xboard(6)

📦

version 4.9.1 · 6 versions

4.9.1 · debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking (latest)
4.9.1-unstable-2026-08 · nixpkgs unstable
4.9.1 · alpine 3.24
4.9.1 · arch rolling, nixos 26.05
4.9.1 · fedora 43
4.9.1 · fedora 44

, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

🌸 xboard — X graphical user interface for chess 🌸

ok so bestie, welcome to xboard(6), from the Games Manual section 💖 this is THE page, and it's a long one, so buckle up 🎀

✨ NAME ✨

xboard — X graphical user interface for chess 👑

🦋 SYNOPSIS 🦋

xboard [options]
xboard -ics -icshost hostname [options]
xboard -ncp [options]
|pxboard
cmail [options]

💅 DESCRIPTION 💅

XBoard is a graphical chessboard, and it's giving main character energy fr fr. It can be your user interface to:

chess engines (like GNU Chess) 🤖
the Internet Chess Servers 🌐
electronic mail correspondence chess 📧
or literally just your own collection of saved games 📚

this manual documents version 4.9.1 of XBoard. no cap.

👑 MAJOR MODES 👑

XBoard always runs in one of four major modes. You pick which one from the command line when you start it up. periodt.

`xboard [options]`

As an interface to GNU Chess or another chess engine running on your machine, XBoard lets you:

play a game against the machine 🎮
set up arbitrary positions
force variations
watch a game between two chess engines 👀
interactively analyze your stored games
set up and analyze arbitrary positions

To run engines that use the UCI standard, XBoard will draw upon the Polyglot adapter fully transparently, but you will need to have the polyglot package installed for this to work. (iykyk)

`xboard -ics -icshost hostname [options]`

As Internet Chess Server (ICS) interface, XBoard lets you play against other ICS users, observe games they are playing, or review games that have recently finished. Most of the ICS "wild" chess variants are supported, including bughouse. 🔥

`xboard -ncp [options]`

XBoard can also be used simply as an electronic chessboard to play through games. It will read and write game files and allow you to play through variations manually. You can use it to browse games off the net or review games you have saved. These features are also available in the other modes. 🫶

`|pxboard`

If you want to pipe games into XBoard, use the supplied shell script pxboard. For example, from the news reader xrn, find a message with one or more games in it, click the Save button, and type |pxboard as the file name. 🌈

`cmail [options]`

As an interface to electronic mail correspondence chess, XBoard works with the cmail program. See CMail below for instructions. 📬

🎀 BASIC OPERATION 🎀

To move a piece, you can drag it with the left mouse button, or you can click the left mouse button once on the piece, then once more on the destination square. 🖱️

To under-promote a Pawn you can drag it backwards until it morphs into the piece you want to promote to, after which you drag that forward to the promotion square. Or after selecting the pawn with a first click you can then click the promotion square and move the mouse while keeping the button down until the piece that you want appears in the promotion square. ✨

To castle you move the King to its destination or, in Chess960, on top of the Rook you want to castle with. 🏰

In crazyhouse, bughouse or shogi you can drag and drop pieces to the board from the holdings squares displayed next to the board.

Old behavior, where right-clicking a square brings up a menu where you can select what piece to drop on it, can still be selected through the Drop Menu option. Only in Edit Position mode right and middle clicking a square is still used to put a piece on it, and the piece to drop is selected by sweeping the mouse vertically with the button held down. 🙈

The default function of the right mouse button in other modes is to display the position the chess program thinks it will end up in. While moving the mouse vertically with this button pressed XBoard will step through the principal variation to show how this position will be reached. Lines of play displayed in the engine-output window, or PGN variations in the comment window, can similarly be played out on the board, by right-clicking on them. Only in Analysis mode, when you walk along a PV, releasing the mouse button might forward the game upto that point, like you entered all previous PV moves. As the display of the PV in that case starts after the first move a simple right-click will play the move the engine indicates. 🧠

In Analysis mode you can also make a move by grabbing the piece with a double-click of the left mouse button (or while keeping the Ctrl key pressed). In this case the move you enter will not be played, but will be excluded from the analysis of the current position. (Or included if it was already excluded; it is a toggle.) This only works for engines that support this feature. 🔁

When connected to an ICS, it is possible to call up a graphical representation of players seeking a game in stead of the chess board, when the latter is not in use (i.e. when you are not playing or observing). Left-clicking the display area will switch between this 'seek graph' and the chess board. Hovering the mouse pointer over a dot will show the details of the seek ad in the message field above the board. Left-clicking the dot will challenge that player. Right-clicking a dot will 'push it to the back', to reveal any dots that were hidden behind it. Right-clicking off dots will refresh the graph. 🎯

Most other XBoard commands are available from the menu bar. The most frequently used commands also have shortcut keys or on-screen buttons. These shortcut keystrokes are mostly non-printable characters. Typing a letter or digit while the board window has focus will bring up a type-in box with the typed letter already in it. You can use that to type a move in situations where it is your turn to enter a move, type a move number to call up the position after that move in the display, or, in Edit Position mode, type a FEN. Some rarely used parameters can only be set through options on the command line used to invoke XBoard. ⌨️

XBoard uses a settings file, in which it can remember any changes to the settings that are made through menus or command-line options, so they will still apply when you restart XBoard for another session. The settings can be saved into this file automatically when XBoard exits, or on explicit request of the user. Note that the board window can be sized by the user, but that this will not affect the size of the clocks above it, and won't be remembered in the settings file. To persistently change the size of the clocks, use the size command-line option when starting XBoard. 💾

The default name for the settings file is /etc/xboard/xboard.conf, but in a standard install this file is only used as a master settings file that determines the system-wide default settings, and defers reading and writing of user settings to a user-specific file like ~/.xboardrc in the user's home directory. 🏠

When XBoard is iconized, its graphical icon is a white knight if it is White's turn to move, a black knight if it is Black's turn. ♞

🌟 MENUS, BUTTONS, AND KEYS 🌟

New Game — Resets XBoard and the chess engine to the beginning of a new chess game. The Ctrl-N key is a keyboard equivalent. In Internet Chess Server mode, clears the current state of XBoard, then resynchronizes with the ICS by sending a refresh command.

If you want to stop playing, observing, or examining an ICS game, use an appropriate command from the Action menu, not New Game. See Action Menu.

New Shuffle Game — Similar to New Game, but allows you to specify a particular initial position (according to a standardized numbering system) in chess variants which use randomized opening positions (e.g. Chess960). 🎲
shuffle — Ticking shuffle will cause the current variant to be played with shuffled initial position. Shuffling will preserve the possibility to castle in the way allowed by the variant.
Fischer castling — Ticking Fischer castling will allow castling with Kings and Rooks that did not start in their normal place, as in Chess960. 🏰
Start-position number
randomize
pick fixed

The Start-position number selects a particular start position from all allowed shufflings, which will then be used for every new game. Setting this to -1 (which can be done by pressing the randomize button) will cause a fresh random position to be picked for every new game. Pressing the pick fixed button causes Start-position number to be set to a random value, to be used for all subsequent games.

New Variant — Allows you to select a new chess variant in non-ICS mode. (In ICS play, the ICS is responsible for deciding which variant will be played, and XBoard adapts automatically.) The shifted Alt+V key is a keyboard equivalent.

If you play with an engine, the engine must be able to play the selected variant, or the corresponding choice will be disabled.

XBoard supports all major variants, such as xiangqi, shogi, chess, chess960, makruk, Capablanca Chess, shatranj, crazyhouse, bughouse. 🌈

You can overrule the default board format of the selected variant, (e.g. to play suicide chess on a 6 x 6 board), in this dialog, but normally you would not do that, and leave them at -1, which means 'default' for the chosen variant.

Load Game — Plays a game from a record file. The Ctrl-O key is a keyboard equivalent. A pop-up dialog prompts you for the file name. If the file contains more than one game, a second pop-up dialog displays a list of games (with information drawn from their PGN tags, if any), and you can select the one you want. Alternatively, you can load the Nth game in the file directly, by typing the number N after the file name, separated by a space. 📂

The game-file parser is so chill about what you feed it — it'll happily accept PGN (portable game notation), or honestly almost any file that contains moves written in algebraic notation. 💅

Piece-drops in bughouse games? Yeah bb, notation of the form P@f7 is accepted for those. It's a nonstandard extension to PGN, iykyk. 🦋

If your file includes a PGN position (that's a FEN tag), or an old-style XBoard position diagram bracketed by [-- and --] before the first move, then the game starts from that position. No cap. ✨

Text wrapped in parentheses, square brackets, or curly braces gets assumed to be commentary and pops up in a little window. 🌸 Anything else in the file? Ignored. Not even a vibe check.

PGN variations (the ones in parentheses) also get treated as comments — but plot twist, bestie: if you right-click them in the comment window, XBoard will shelve the current line and load the selected variation, so you can step through it. You can always bounce back to the previous line later with the Revert command. So basically you can walk through quite complex variation trees with XBoard. The range? Unmatched. 🌈

There's also a nonstandard PGN tag — [Variant "varname"] — and it functions similarly to the -variant command-line option (see below), letting games in certain chess variants get loaded up. 👑

⚠️ Heads up though: it must appear before any FEN tag for XBoard to recognize variant FENs appropriately. Order matters, don't play yourself.

There's also a heuristic that recognizes chess variants from the Event tag, by looking for the strings that the Internet Chess Servers put there when saving variant ("wild") games. 🧚

🎀 Load Position 🎀

Sets up a position from a position file. A pop-up dialog asks you for the file name, cute and simple. The shifted Ctrl-O key is the keyboard equivalent.

If the file contains more than one saved position and you want to load the Nth one, type the number N after the file name, separated by a space. 🍓

Position files have to be in FEN (Forsythe-Edwards notation), or in the format that the Save Position command writes when oldSaveStyle is turned on.

🎀 Load Next Position 🎀

Loads the next position from the last position file you loaded. The shifted PgDn key is a keyboard equivalent. 💖

🎀 Load Previous Position 🎀

Loads the previous position from the last position file you loaded. The shifted PgUp key is a keyboard equivalent.

Not available if the last position was loaded from a pipe. Just saying. 🙈

🎀 Save Game 🎀

Appends a record of the current game to a file. The Ctrl-S key is a keyboard equivalent. A pop-up dialog prompts you for the file name.

If the game did not begin with the standard starting position, the game file includes the starting position that was used. 📌

Games are saved in the PGN (portable game notation) format, unless the oldSaveStyle option is true — in which case they get saved in an older format that's specific to XBoard. Both formats are human-readable, and both can be read back by the Load Game command. 🫶

Notation of the form P@f7 is accepted for piece-drops in bughouse games; this is a nonstandard extension to PGN.

🎀 Save Position 🎀

Appends a diagram of the current position to a file. The shifted Ctrl+S key is a keyboard equivalent. A pop-up dialog prompts you for the file name.

Positions are saved in FEN (Forsythe-Edwards notation) format unless the oldSaveStyle option is true, in which case they're saved in an older, human-readable format that's specific to XBoard. Both formats can be read back by the Load Position command. ✨

🎀 Save Selected Games 🎀

Will cause all games selected for display in the current Game List to be appended to a file of the user's choice. 💅

🎀 Save Games as Book 🎀

Creates an opening book from the currently loaded game file, incorporating only the games currently selected in the Game List.

The book will be saved on the file specified in the Common Engine options dialog. The value of Book Depth specified in that same dialog is what determines how many moves of each game get added to the internal book buffer.

This command can take a long time to process, and the size of the buffer is currently limited. Fair warning bestie, go make a snack. 😭

At the end the buffer will be saved as a Polyglot book, but the buffer will not be cleared — so you can keep adding games from other game files. Obsessed with the convenience actually. 👑

🎀 Mail Move 🎀

🎀 Reload CMail Message 🎀

See CMail.

🎀 Exit 🎀

Exits from XBoard. The Ctrl-Q key is a keyboard equivalent.

🌟 Copy Game 🌟

Copies a record of the current game to an internal clipboard in PGN format, and sets the X selection to the game text. The Ctrl-C key is a keyboard equivalent.

The game can then be pasted to another application (like a text editor, or another copy of XBoard) using that application's paste command. In many X applications, such as xterm and emacs, the middle mouse button can be used for pasting — but in XBoard, you must use the Paste Game command. 🫶

🌟 Copy Position 🌟

Copies the current position to an internal clipboard in FEN format, and sets the X selection to the position text. The shifted Ctrl-C key is a keyboard equivalent.

The position can be pasted to another application (like a text editor, or another copy of XBoard) using that application's paste command. In many X applications, such as xterm and emacs, the middle mouse button can be used for pasting — but in XBoard, you must use the Paste Position command. 💅

🌟 Copy Game List 🌟

Copies the current game list to the clipboard, and sets the X selection to this text.

A format of comma-separated double-quoted strings is used, including all tags, so it can be easily imported into spread-sheet programs. Slay. 📊

🌟 Paste Game 🌟

Interprets the current X selection as a game record and loads it, as with Load Game. The Ctrl-V key is a keyboard equivalent. ✨

🌟 Paste Position 🌟

Interprets the current X selection as a FEN position and loads it, as with Load Position. The shifted Ctrl-V key is a keyboard equivalent. ✨

🌟 Edit Game 🌟

Allows you to make moves for both Black and White, and to change moves after backing up with the Backward command. The clocks do not run. The Ctrl-E key is a keyboard equivalent. ⏱️

In chess engine mode, the chess engine continues to check moves for legality but does not participate in the game. You can bring the chess engine into the game by selecting Machine White, Machine Black, or Two Machines. 👑

In ICS mode, the moves are not sent to the ICS: Edit Game takes XBoard out of ICS Client mode and lets you edit games locally. If you want to edit games on ICS in a way that other ICS users can see, use the ICS examine command, or start an ICS match against yourself. 🌸

🌟 Edit Position 🌟

Lets you set up an arbitrary board position. The shifted Ctrl-E key is a keyboard equivalent.

Use mouse button 1 to drag pieces to new squares, or to delete a piece by dragging it off the board or dragging an empty square on top of it. When you do this keeping the Ctrl key pressed, or start dragging with a double-click, you'll move a copy of the piece, leaving the piece itself where it was. 🦋

In variants where pieces can promote (such as Shogi), left-clicking an already selected piece promotes or demotes it.

To drop a new piece on a square, press mouse button 2 or 3 over the square. This puts a white or black pawn in the square, respectively, but you can change that to any other piece type by dragging the mouse down before you release the button. You'll then see the piece on the originally clicked square cycle through the available pieces (including those of opposite color), and can release the button when you see the piece you want. 🌈

(Note you can swap the function of button 2 and 3 by pressing the shift key, and that there is an option monoMouse to combine all functions in one button, which then acts as button 3 over an empty square, and as button 1 over a piece.)

To alter the side to move, you can click the clock (the words White and Black above the board) of the side you want to give the move to. To clear the board you can click the clock of the side that already has the move (which is highlighted in black).

If you repeat this, the board will cycle from empty to a pallette board containing every piece once to the initial position to the one before clearing. 🎨

The quickest way to set up a position is usually to start with the pallette board, and move the pieces to where you want them, duplicating them where necessary by using the Ctrl key, dragging those you don't want off board, and use static button 2 or 3 clicks to place the Pawns. The old behavior with a piece menu can still be configured with the aid of the pieceMenu option. 📌

Dragging empty squares off board can create boards with holes (inaccessible black squares) in them.

Selecting Edit Position causes XBoard to discard all remembered moves in the current game. Gone. Poof. 💀

In ICS mode, changes made to the position by Edit Position are not sent to the ICS: Edit Position takes XBoard out of ICS Client mode and lets you edit positions locally. If you want to edit positions on ICS in a way that other ICS users can see, use the ICS examine command, or start an ICS match against yourself. (See also the ICS Client topic above.) 🌸

🌟 Edit Tags 🌟

Lets you edit the PGN (portable game notation) tags for the current game. After editing, the tags must still conform to the PGN tag syntax:

<tag-section> ::= <tag-pair> <tag-section>
                        <empty>
<tag-pair> ::= [ <tag-name> <tag-value> ]
<tag-name> ::= <identifier>
<tag-value> ::= <string>

See the PGN Standard for full details. Here's an example, bestie:

[Event "Portoroz Interzonal"]
[Site "Portoroz, Yugoslavia"]
[Date "1958.08.16"]
[Round "8"]
[White "Robert J. Fischer"]
[Black "Bent Larsen"]
[Result "1-0"]

Any characters that don't match that syntax? silently ignored, bestie. Not a whisper, not a peep. 😶 And lowkey important: the PGN standard says every game has to carry at least those seven tags we showed you up above. If you leave any out, XBoard fills them in for you — with ? for an unknown value, or - for a value that just doesn't apply. 🫶

Edit Comment

Adds or modifies a comment on the current position. ✍️ Comments get saved by Save Game and shown again by Load Game. PGN variations also get printed in this very window, and you can promote one to the main line just by right-clicking it. Forward, and Backward do their thing in here too.

Edit Book

Pops up a window listing all the moves available in the GUI book — the one you specified over in the Common Engine Settings dialog — from whatever position you're currently displaying, together with their weights and (optionally, in braces) their learn info. 📖 You can then edit that list, and the new list gets stored straight back into the book when you press 'save changes'. And when you press the button 'add next move' and then play a move on the board, that move gets added to the list with weight 1. Heads up though: those listed percentages are neither used nor updated when you change the weights — they're literally just there as an optical aid, bestie, purely decorative. 💅 Right-click a move in the list and it'll get played.

Revert / Annotate

If you're examining an ICS game and Pause mode is off, Revert issues the ICS command revert. In local mode, when you were editing or analyzing a game and the -variations command-line option is switched on, you can start a new variation by holding the Shift key down while entering a move that isn't at the end of the game. Variations can also become the currently displayed line if you click a PGN variation shown in the Comment window. 🦋 And this works recursively — variations on variations on variations, the whole vibe — because each time you create a new variation by entering an alternative move with Shift pressed, or select a new one from the Comment window, the current variation gets shelved. Revert lets you go back to the most recently shelved variation.

The difference between Revert and Annotate? With Annotate, the variation you're now abandoning gets added as a comment — in PGN variation syntax, i.e. between parentheses — onto the original move where you deviated, so you can recall it later. 🎀 And the Home key is a keyboard equivalent to Revert.

Truncate Game

Discards all remembered moves of the game beyond the current position. 😤 Puts XBoard into Edit Game mode if it wasn't there already. The End key is a keyboard equivalent.

Backward (`<`)

Steps backward through a series of remembered moves. The [<] button and the Alt+LeftArrow key are equivalents, and so is turning the mouse wheel towards you. 🖱️ Bonus: pressing the ??? key steps back one move, and releasing it steps forward again.

In most modes, Backward only lets you look back at old positions — it does not retract moves. That's the case if you're playing against a chess engine, playing or observing a game on an ICS, or loading a game. So if you hit Backward in any of those situations, you will not be allowed to make a different move. 😭 Use Retract Move or Edit Game if you actually want to change past moves.

If you're examining an ICS game, what Backward does depends on whether XBoard is in Pause mode. Pause mode off → Backward issues the ICS backward command, which backs up everyone's view of the game and lets you make a different move. Pause mode on → Backward only backs up your own local view. ✨

Forward (`>`)

Steps forward through a series of remembered moves (undoing the effect of Backward) or forward through a game file. The [>] button and the Alt+RightArrow key are equivalents, and so is turning the mouse wheel away from you. 🖱️

If you're examining an ICS game, the behavior of Forward depends on whether XBoard is in Pause mode. Pause mode off → Forward issues the ICS forward command, which moves everyone's view of the game forward along the current line. Pause mode on → Forward only moves your local view forward, and it will not go past the position the game was in when you paused. 🛑

Back to Start (`<<`)

Jumps backward to the first remembered position in the game. The [<<] button and the Alt+Home key are equivalents. ⏮️

In most modes, Back to Start only lets you look back at old positions; it does not retract moves. That's the case if you're playing against a local chess engine, playing or observing a game on a chess server, or loading a game. If you select Back to Start in any of those situations, you will not be allowed to make different moves. Use Retract Move or Edit Game if you want to change past moves; or use Reset to start a whole new game. 🌸

If you're examining an ICS game, the behavior of Back to Start depends on whether XBoard is in Pause mode. Pause mode off → Back to Start issues the ICS backward 999999 command, which backs up everyone's view of the game to the start and lets you make different moves. Pause mode on → Back to Start only backs up your local view. 💜

Forward to End (`>>`)

Jumps forward to the last remembered position in the game. The [>>] button and the Alt+End key are equivalents. ⏭️

If you're examining an ICS game, the behavior of Forward to End depends on whether XBoard is in Pause mode. Pause mode off → Forward to End issues the ICS forward 999999 command, which moves everyone's view of the game forward to the end of the current line. Pause mode on → Forward to End only moves your local view forward, and it will not go past the position the game was in when you paused. 🧚

Flip View

Inverts your view of the chess board for the duration of the current game. 🔄 Starting a new game returns the board to normal, no cap. The F2 key is a keyboard equivalent.

Show Engine Output

Shows or hides a window where the thinking output of any loaded engines gets displayed. 👀 The shifted Alt+O key is a keyboard equivalent.

Here's the tea: XBoard displays lines of thinking output of the same depth ordered by score (highest score on top), rather than in the order the engine produced them. Usually that amounts to the same thing, because a normal engine search will only find a new PV — and emit it as thinking output — when it searches a move with a higher score than the previous variation. But when the engine is in multi-variation mode, that need not always be true, and honestly it's way more convenient for someone analyzing games to see the moves sorted by score. 📊 The order in which the engine found them is only of interest to the engine author, and you can still deduce it from the time or node count printed with the line. iykyk.

Right-clicking a line in this window, and then moving the mouse vertically with the right button kept down, will make XBoard play through the PV listed there. 🎬 The use of the board window as 'variation board' will normally end when you release the right button, or when the opponent plays a move. But beware: in Analysis mode, moves thus played out might be added to the game, depending on the setting of the option 'Play moves of clicked PV', when you initiate the click left of the PV in the score area. ⚠️

The Engine-Output pane for each engine will contain a header displaying the multi-PV status and a list of excluded moves in Analysis mode, and those are responsive to right-clicking too: clicking the words 'fewer' or 'more' alters the number of variations shown at each depth, through the engine's MultiPV option, while clicking in between those and moving the mouse horizontally adjusts the option 'Multi-PV Margin'. (In so far the engines support those.) 🎛️

Show Move History

Shows or hides a list of moves of the current game. 📜 The shifted Alt+H key is a keyboard equivalent. This list lets you move the display to any earlier position in the game just by clicking on the corresponding move — iconic.

Show Evaluation Graph

Shows or hides a window that displays a graph of how the engine score(s) evolved as a function of the move number. 📈 The shifted Alt+E key is a keyboard equivalent. The title bar shows the score (and the search depth at which it was obtained) of the currently displayed position, numerically. Clicking on the graph brings the corresponding position up in the board display. A button 3 click toggles the display mode between plain and differential (showing the difference in score between successive half moves). And using the mouse wheel over the window changes the scale of the low-score region (from -1 to +1). 🎡

Show Game List

Shows or hides the list of games generated by the last Load Game command. 🗂️ The shifted Alt+G key is a keyboard equivalent.

The line describing each game is built from a selection of the PGN tags. Which tags contribute, and in what order, can be changed by the Game list tags menu dialog, which you pop up through the Tags button below the Game List. Display can be restricted to a sub-set of the games meeting certain criteria. A text entry below the game list lets you type a text that the game lines must contain in order to be displayed. Games can also be selected based on their Elo PGN tag, as set in the Load Game Options dialog, which you pop up through the Thresholds button below the Game List. 🏷️

And finally, they can be selected based on containing a position similar to the one currently displayed in the main window, by pressing the 'Position' button below the Game List (which searches the entire list for the position), or the 'Narrow' button (which only searches the already-selected games). 🔍 What counts as similar enough to be selected can also be set in the Load Game Options dialog, and it ranges all the way from an exact match to just the same material. ✨

Tags — pops open a whole window showing the PGN (portable game notation) tags for the game you're currently in. ngl, right now it's just a duplicate of the Edit Tags item living in the Edit menu. Same energy, same thing. 🏷️
Comments — opens up a window showing whatever comments or variations are attached to the current move. And yeah, for now it's a straight duplicate of the Edit Comment item in the Edit menu. 💬
ICS Input Box — if you've got this turned on in ICS mode, XBoard makes you an extra little window just for typing in ICS commands. Bestie, this is a lifesaver when you wanna type something long or actually edit your input, because the ICS output does NOT get mixed in with your typing like it would in the main terminal window. chef's kiss. ✨
ICS/Chat Console — this menu item opens a window where you can interact with the ICS directly, so you don't have to use that messy xterm you launched XBoard from. periodt. The window has a text entry at the bottom for typing your commands and messages totally unhindered by the stream of ICS output — and that output gets displayed in a big pane above the input field, aka the ICS Console. Up and down arrow keys recall your previous input lines. Type an <Esc> character in the input field and focus hops back to the board window (so you can run the menus there with accelerator keys). Type any printable character in the board window and focus comes right back to the input field of the ICS Chat/Console window. 🦋
Chats — there's a row of buttons at the top of the ICS Chat/Console dialog, and you use them to navigate between up to 5 'chats' with other ICS users (or channels). These switch the window into 'chat mode', where the ICS output pane gets vertically split so messages from one specific user or ICS channel get diverted to the lower half. Lines you type in the input field then get read as messages to send to that user or channel — automatically prefixed with the appropriate ICS command and user name — instead of as commands to the ICS. Chats keep collecting their ICS output even when they're not on screen, and their buttons turn orange to let you know there's been activity. Typing <Tab> in the input field switches you to another active chat, and it gives priority to the ones with content you haven't seen yet. 👑
New Chat — buttons for chats that aren't currently assigned to a user or channel carry the text New Chat, and pressing one switches you to chat mode so you can type in the user name or channel number you want it for. Typing Ctrl-N in the input field is the keyboard equivalent. 💅
Chat partner — to (re-)assign a chat, write the name of your chat partner, the channel number, or the words 'shouts', 'whispers', 'cshouts' in the Chat partner text entry (and end it with <Enter>!). Typing Ctrl-O in the input field at the bottom of the window opens a chat with the person who last sent you a 'tell' that got printed in the ICS Console output pane. The ICS text menu can hold a button Open Chat (name) that opens a chat with, as partner, the word/number you right-clicked in the output pane to pop that menu up. 🫶
End Chat — this button only shows up when the chat pane is open, and it clears the Chat partner field so the chat can be reassigned to a new user or channel. Typing Ctrl-E in the input field is the keyboard equivalent. 🙈
Hide — also only visible when the chat pane is open, this button closes the pane so you can use the input field to give commands to the ICS again. Typing Ctrl-H in the input field is the keyboard equivalent. 🌸
ICS text menu — brings up a menu you can configure yourself through the icsMenu option. Buttons in this menu can send pre-configured commands straight to the ICS, or they can drop partial commands into the input field of the ICS Chat/Console window so you can finish them off with some text of your own before sending them with Enter. You can also pop this menu up by right-clicking in the text memos of the ICS Chat/Console window — and in that case, the word you clicked can get incorporated into the message sent to the ICS. E.g. to challenge a player whose name you clicked for a game, or to prepare sending him a message through a 'tell' command. iykyk. 🌈
Edit ICS menu — brings up an edit box with the definition of the ICS text menu, so you can adapt its appearance to whatever you need. The menu is defined by a semi-colon-separated list, with each button taking up a pair of items in it. The first item of each pair is the text on the button, the second is the text sent when the button is pressed. The word $input in the text puts that text in the input field of the ICS Chat/Console with the cursor in that exact place, and the word $name gets replaced by the word you right-clicked to pop up the text menu. 🔥
Edit Theme List — brings up an edit box with the definitions of the themes shown in the listbox of the Board dialog, so you can delete, re-order, or alter themes you defined before. ✨
Board — summons a dialog where you customize the look of the chess board. 💖
White Piece Color
Black Piece Color
Light Square Color
Dark Square Color
Highlight Color
Premove Highlight Color — these items set the color of the pieces, the board squares, and the move highlights (borders or arrow). Heads up: square colors only get used when the Use Board Textures option is off, and the piece colors only when Use piece bitmaps with their own colors is off. You can type the color as a hexadecimally encoded RGB value preceded by #, or tweak it with the R, G, B, and D buttons to make it redder, greener, bluer, or darker. A sample of the adjusted color shows up behind its text description, and pressing that colored button restores the default value for the color. 🎨
Flip Pieces Shogi Style — with this option on, XBoard swaps the white and black pieces whenever you flip the view of the board to make white play downward. Use it with piece themes that don't tell sides apart by color, but by orientation. 🧚
Mono Mode — this option puts XBoard in pure black-and-white display: no grey scales, and therefore no anti-aliasing. 💀
Logo Size — specifies the width of the engine logos displayed next to the clocks, in pixels. Set it to 0 and those logos just don't show. The height of the logo will be half its width. In the GTK build of XBoard any non-zero value is equivalent, and the logos are always sized to 1/4 of the board width. 📏
Line Gap — specifies the width of the grid lines that separate the squares, which change color when a move is highlighted. Set it to 0 and those lines vanish, which generally looks better, but it hides the square-border highlights — so you'd have to rely on other forms of highlighting. Set the value to -1 and XBoard picks a width by itself, depending on the square size. 🌟
Use Board Textures
Light-Squares Texture File
Dark-Squares Texture File — when Use Board Textures is set, the squares aren't drawn as evenly colored surfaces, they get cut from a texture image as specified by the Texture Files. Separate images can be used for light and dark squares. XBoard will try to cut the squares out of the texture image with as little overlap as possible, so they all look different. The name of the texture file can carry a size hint, e.g. xqboard-9x10.png, which alerts XBoard to the fact that it contains a whole-board image, out of which squares have to be cut in register with the nominal sub-division. 🎀
Use external piece bitmaps with their own color — when this is on, XBoard ignores the piece-color settings and draws the piece images in their original colors. The piece-color settings would only work well for evenly colored pieces, like the default theme. 🖼️
Directory with Pieces Images — when a directory is specified here, XBoard first looks for piece images (SVG or PNG files) in that directory, and only falls back on the image from the default theme for the images it can't find there. An image file called White/BlackTile in the directory will be preferred as fall-back for missing pieces over the default image, though. 📁
Selectable themes
New name for current theme — when a theme name is specified while you press 'OK', the combination of settings in the dialog gets stored in XBoard's list of themes, which is saved along with the other options in the settings file (as the themeNames option). That name then shows up in the selection listbox next time you open the dialog, so you can recall the entire combination of settings by double-clicking it.

Here you can specify the directory from which piece images should be taken, when you don't want the built-in piece images (see the pieceImageDirectory option), external images to use for the board squares (the liteBackTextureFile and darkBackTextureFile options), and the square and piece colors for the default pieces. The current combination of these settings can be given a 'theme' name by typing one into the text entry in the lower-left of the dialog and closing it with OK. It'll then appear in the themes listbox next time you open the dialog, where you can recall the complete settings combination with a double-click. 👑

Fonts — pops up a dialog where you set the fonts used in the main elements of the various windows. Pango font names can be typed for each window type, and behind each text entry there are buttons to adjust the point size, and toggle the 'bold' or 'italic' attributes of the font. 🖋️
Game List Tags — a duplicate of the Game List dialog in the Options menu.

Machine White — tells the chess engine to play White. The Ctrl-W key is the keyboard equivalent. ⭐

🖤 Machine Black

Tells the chess engine to play Black, bestie. That's it, that's the whole vibe. The Ctrl-B key is a keyboard equivalent. 💅

🎮 Two Machines

Plays a whole game between two chess engines and you just sit there like 👑 watching them go. The Ctrl-T key is a keyboard equivalent.

🔍 Analysis Mode

XBoard tells the chess engine to start analyzing the current game/position and shows you the analysis as you move pieces around. The Ctrl-A key is a keyboard equivalent.

Note: Some chess engines do not support Analysis mode. Not every engine is main-character enough for this, no cap. 😭

So to set up a position to analyze, here's the lil ritual:

Set up the position by any means. (E.g. using Edit Position mode, pasing a FEN or loading a game and stepping to the position.)
Select Analysis Mode from the Mode Menu to start the analysis.

You can now play legal moves to create follow-up positions for the engine to analyze, while the moves will be remembered as a stored game, and then step backward through this game to take the moves back. Note that you can also click on the clocks to set the opposite side to move (adding a so-called null move to the game). ✨

You can also tell the engine to exclude some moves from analysis. (Engines that do not support the exclude-moves feature will ignore this, however.) The general way to do this is to play the move you want to exclude starting with a double click on the piece. When you use drag-drop moving, the piece you grab with a double click will also remain on its square, to show you that you are not really making the move, but just forbid it from the current position. Playing a thus excluded move a second time will include it again. Excluded moves will be listed as text in a header line in the Engine Output window, and you can also re-include them by right-clicking them there. This header line will also contain the words 'best' and 'tail'; right-clicking those will exclude the currently best move, or all moves not explicitly listed in the header line. Once you leave the current position all memory of excluded moves will be lost when you return there. 🙈

Selecting this menu item while already in Analysis Mode will toggle the participation of the second engine in the analysis. The output of this engine will then be shown in the lower pane of the Engine Output window. The analysis function can also be used when observing games on an ICS with an engine loaded (zippy mode); the engine then will analyze the positions as they occur in the observed game. 🦋

📊 Analyze Game

This option subjects the currently loaded game to automatic analysis by the loaded engine. The Ctrl-G key is a keyboard equivalent. XBoard will start auto-playing the game from the currently displayed position, while the engine is analyzing the current position. The game will be annotated with the results of these analyses. In particlar, the score and depth will be added as a comment, and the PV will be added as a variation. 🔥

Normally the analysis would stop after reaching the end of the game. But when a game is loaded from a multi-game file while Analyze Game was already switched on, the analysis will continue with the next game in the file until the end of the file is reached (or you switch to another mode). It just keeps going, iconic behaviour fr fr.

The time the engine spends on analyzing each move can be controlled through the command-line option -timeDelay, which can also be set from the Load Game Options menu dialog.

Note: Some chess engines do not support Analysis mode. 💀

✏️ Edit Game

Duplicate of the item in the Edit menu. Note that Edit Game is the idle mode of XBoard, and can be used to get you out of other modes. E.g. to stop analyzing, stop a game between two engines or stop editing a position. It's basically the "touch grass" button. 🌸

📐 Edit Position

Duplicate of the item in the Edit menu.

🧠 Training

Training mode lets you interactively guess the moves of a game for one of the players. You guess the next move of the game by playing the move on the board. If the move played matches the next move of the game, the move is accepted and the opponent's response is auto-played. If the move played is incorrect, an error message is displayed. You can select this mode only while loading a game (that is, after selecting Load Game from the File menu). While XBoard is in Training mode, the navigation buttons are disabled. 😤

🌐 ICS Client

This is the normal mode when XBoard is connected to a chess server. If you have moved into Edit Game or Edit Position mode, you can select this option to get out. 🫶

To use xboard in ICS mode, run it in the foreground with the -ics option, and use the terminal you started it from to type commands and receive text responses from the chess server. See Chess Servers below for more information.

XBoard activates some special position/game editing features when you use the examine or bsetup commands on ICS and you have ICS Client selected on the Mode menu. First, you can issue the ICS position-editing commands with the mouse. Move pieces by dragging with mouse button 1. To drop a new piece on a square, press mouse button 2 or 3 over the square. This brings up a menu of white pieces (button 2) or black pieces (button 3). Additional menu choices let you empty the square or clear the board. Click on the White or Black clock to set the side to play. You cannot set the side to play or drag pieces to arbitrary squares while examining on ICC, but you can do so in bsetup mode on FICS. In addition, the menu commands Forward, Backward, Pause, and Stop Examining have special functions in this mode; see below. ✨

🏆 Machine Match

Starts a match between two chess programs, with a number of games and other parameters set through the Tournament Options menu dialog. When a match is already running, selecting this item will make XBoard drop out of match mode after the current game finishes. 👑

⏸️ Pause

Pauses updates to the board, and if you are playing against a chess engine, also pauses your clock. To continue, select Pause again, and the display will automatically update to the latest position. The P button and keyboard Pause key are equivalents. 🎀

If you select Pause when you are playing against a chess engine and it is not your move, the chess engine's clock will continue to run and it will eventually make a move, at which point both clocks will stop. Since board updates are paused, however, you will not see the move until you exit from Pause mode (or select Forward). This behavior is meant to simulate adjournment with a sealed move.

If you select Pause while you are observing or examining a game on a chess server, you can step backward and forward in the current history of the examined game without affecting the other observers and examiners, and without having your display jump forward to the latest position each time a move is made. Select Pause again to reconnect yourself to the current state of the game on ICS. 🦋

If you select Pause while you are loading a game, the game stops loading. You can load more moves manually by selecting Forward, or resume automatic loading by selecting Pause again.

🤝 Accept

Accepts a pending match offer. The F3 key is a keyboard equivalent. If there is more than one offer pending, you will have to type in a more specific command instead of using this menu choice. 🙃

🙅 Decline

Declines a pending offer (match, draw, adjourn, etc.). The F4 key is a keyboard equivalent. If there is more than one offer pending, you will have to type in a more specific command instead of using this menu choice.

🚩 Call Flag

Calls your opponent's flag, claiming a win on time, or claiming a draw if you are both out of time. The F5 key is a keyboard equivalent. You can also call your opponent's flag by clicking on his clock. 😌

🪢 Draw

Offers a draw to your opponent, accepts a pending draw offer from your opponent, or claims a draw by repetition or the 50-move rule, as appropriate. The F6 key is a keyboard equivalent.

🕰️ Adjourn

Asks your opponent to agree to adjourning the current game, or agrees to a pending adjournment offer from your opponent. The F7 key is a keyboard equivalent.

🛑 Abort

Asks your opponent to agree to aborting the current game, or agrees to a pending abort offer from your opponent. The F8 key is a keyboard equivalent. An aborted game ends immediately without affecting either player's rating. ✨

🏳️ Resign

Resigns the game to your opponent. The F9 key is a keyboard equivalent. 😭

👀 Stop Observing

Ends your participation in observing a game, by issuing the ICS observe command with no arguments. ICS mode only. The F10 key is a keyboard equivalent.

🔎 Stop Examining

Ends your participation in examining a game, by issuing the ICS unexamine command. ICS mode only. The F11 key is a keyboard equivalent.

📤 Upload to Examine

Create an examined game of the proper variant on the ICS, and send the game there that is currenty loaded in XBoard (e.g. through pasting or loading from file). You must be connected to an ICS for this to work. 🫶

⚖️ Adjudicate to White / Adjudicate to Black / Adjudicate Draw

Adjudicate to White
Adjudicate to Black
Adjudicate Draw

Terminate an ongoing game in Two-Machines mode (including match mode), with as result a win for white, for black, or a draw, respectively. The PGN file of the game will accompany the result string by the comment "user adjudication". 👑

📝 Edit Engine List

Opens a window that shows the list of engines registered for use by XBoard, together with the options that would be used with them when you would select them from the Load Engine dialogs. You can then edit this list, e.g. for re-ordering the engines, or adding uncommon options needed by this engine (e.g. to cure non-compliant behavior). It's giving engine rosters, and we're obsessed. 💖

okay so here's a lil secret about the editing situation: you can also organize the engines into collapsible groups 🎀 Here's the trick — sandwich a bunch of engine lines between a line that says # NAME and a line that says # end, and the engines you tucked in there will not initially show up in the engine listboxes of other dialogs. Nope. Instead, only that single line # NAME appears in their place (and NAME can be literally any arbitrary text you want, slay). Select that line and boom, the enclosed engines appear in the listbox — and yes bestie, those can recursively contain other groups too, it's giving nesting doll energy 🪆 The line with the group name will still present as a header, and selecting that line will collapse the group again, which makes the listbox go back to displaying the surrounding group. Collapse and expand, main character behavior 💅

Load New 1st Engine
Load New 2nd Engine — Pops up a dialog where you can select or specify an engine to be loaded ✨ You can even swap out engines during a game without disturbing that game, iconic. > ⚠️ But beware bestie: after loading an engine, XBoard will always be in Edit Game mode, so you will have to tell the new engine what to do before it does anything! No cap.
Select engine from list — The listbox shows the engines registered for use with XBoard before. (Which means XBoard has info on the engine type, whether it plays book etc., all chillin' in the engine list stored in its settings file 💾) Double-clicking an engine here will load it and close the dialog. The list can also contain groups, indicated by a starting # sign. Double-clicking such a group will 'open' it and show the group contents in the listbox instead of the total list, with the group name as header. Double-clicking the header will 'close' the group again 🔁
Nickname
Use nickname in PGN player tags of engine-engine games — When a Nickname is specified, the engine will appear under this name in the Select Engine listbox. Otherwise the name there will be a tidied version of the engine command. The user can specify if the nickname is also to be used in PGN tags; normally the name engines report themselves would be used there 🏷️
Engine Command — The command needed to start the engine from the command line. For a compliantly installed engine this is usually just a single word, the name of the engine package (e.g. crafty or stockfish) 🐟 Some engines need additional parameters on the command line. For engines that are not in a place where the system would expect them, a full pathname can be specified, and usually the browse button for this option is the easiest way to obtain that.
Engine Directory — Compliant engines could run from any directory, and by default this option is proposed as ., the current directory. If a (path)name is specified here, XBoard will start the engine in that directory 📁 If you make the field empty, it will try to derive the directory from the engine command (if that was a path name).
UCI — When the UCI checkbox is ticked, XBoard will assume the engine is of UCI type, and will invoke the corresponding adapter (as specified in the adapterCommand option stored in its settings file) to use it. By default this adapter is Polyglot, which must be installed from a separate package! 🫶
USI/UCCI — Ticking this checkbox informs XBoard that the engine is of USI or UCCI type (as Shogi or Xiangqi engines often are). This makes XBoard invoke an adapter to run the engines, as specified by the uxiAdapter option stored in its settings file. The UCI2WB program is an adapter that can handle both these engine types, as well as UCI 🌈
WB protocol v1 — Ticking this checkbox informs XBoard the engine is using an old version (1) of the communication protocol, so that it won't respond to a request to interrogate its properties. XBoard then won't even try that, saving you a wait of several seconds each time the engine is started ⏳ > ⚠️ Do not use this on state-of-the-art engines, as it would prevent XBoard from interrogating its capabilities, so that many of its features might not work!
Must not use GUI book — By default XBoard assumes engines are responsible for their own opening book, but unticking this option makes XBoard consult its own book (as per Opening-Book Filename) on behalf of the engine 📖
Add this engine to the list — By default XBoard would add the engine you specified, with all the given options, to its list of registered engines (kept in its settings file) when you press 'OK'. Next time you could then simply select it from the listbox, or use the command xboard -fe NICKNAME to start XBoard with the engine and accompanying options 😌 New engines are always added at the end of the existing list, or, when you have opened a group in the Select Engine listbox, at the end of that group. But it can be re-ordered later with the aid of the Edit Engine List menu item. When you untick this checkbox before pressing 'OK', the engine will be loaded, but will not be added to the engine list.
Force current variant with this engine — Ticking this option will make XBoard automatically start the engine in the current variant, even when XBoard was set for a different variant when you loaded the engine. Useful when the engine plays multiple variants, and you specifically want to play one different from its primary one 🎯
Engine #1 Settings
Engine #2 Settings — Pop up a menu dialog to alter the settings specific to the applicable engine. For each parameter the engine allows to be set, a control element will appear in this dialog that can be used to alter the value. Depending on the type of parameter (text string, number, multiple choice, on/off switch, instantaneous signal), the appropriate control will appear, with a description next to it 📝 XBoard has no idea what these values mean; it just passes them on to the engine. How this dialog looks is completely determined by the engine, and XBoard just passes it on to the user. Many engines do not have any parameters that can be set by the user, and in that case the dialog will be empty (except for the OK and cancel buttons). UCI engines usually have many parameters. (But these are only visible with a sufficiently modern version of the Polyglot adapter needed to run UCI engines, e.g. Polyglot 2.0.1.) For native XBoard engines this is less common.
Common Settings — Pops up a menu dialog where you can set some engine parameters common to most engines, such as hash-table size, tablebase cache size, and maximum number of processors that SMP engines can use 🧠 The shifted Alt+U key is a keyboard equivalent. Older XBoard/WinBoard engines might not respond to these settings, but UCI engines always should.
Maximum Number of CPUs per Engine — Specifies the number of search threads any engine can maximally use. > ⚠️ Do not set it to a number larger than the number of cores your computer has. (Or half of it when you want two engines to run simultaneously, as in a Two-Machines game with Ponder Next Move on.)
Polyglot Directory — (no blurb for this one in the docs, bestie, it's just vibes and a path 🦋)
Hash-Table Size — Specifies the maximum amount of memory (RAM) each engine is allowed to use for storing info on positions it already searched, so it would not have to search them again. > ⚠️ Do not set it so that it is more than half (or if you use two engines, more than a quarter) of the memory your computer has, or it would slow the engines down by an extreme amount 💀
EGTB Path — Sets the value of the egtFormats option, which specifies where on your computer the files for End-Game Tables are stored. It must be a comma-separated list of path names, the path for each EGT flavor prefixed with the name of the latter and a colon. E.g. "nalimov:/home/egt/dtm,syzygy:/home/egt/dtz50". The path names after the colon will be sent to the engines that say they can use the corresponding EGT flavor 🔥
EGTB Cache Size — Specifies the amount of memory the engine should use to buffer end-game information. Together with the Hash-Table Size this determines how much memory the engine is allowed to use in total 🍓
Use GUI Book
Opening-Book Filename — The Opening-Book Filename specifies an opening book in Polyglot format (usually a .bin file), from which XBoard can play moves on behalf of the engine 📚 This is also the book file on which the Edit Book and Save Games as Book menu items operate. A checkbox Use GUI Book can be used to temporarily disable the book without losing the setting. (This does not prevent editing or saving games on it!)
Book Depth
Book Variety — The way moves are selected from the book can be controlled by two options. Book Depth controls for how deep into the game the book will be consulted (measured in full moves). Book Variety controls the likelihood of playing weaker moves. When the variety is set to 50, moves will be played with the probability specified in the book. When set to 0, only the move(s) with the highest probability will be played. When set to 100, all listed moves will be played with equal probability. Other settings interpolate between that 🎲
Engine #1 Has Own Book
Engine #2 Has Own Book — These checkboxes control on a per-engine basis whether XBoard will consult the opening book for them. If ticked, XBoard will never play moves from its GUI book, giving the engine the opportunity to use its own. These options are automatically set whenever you load an engine, based on the setting of Must not use GUI book when you installed that through the Load Engine menu dialog 🫶
Hint — Displays a move hint from the chess engine 💡

Book — pops up a lil list of possible moves straight from the chess engine's opening book, bestie 📖. The exact format is literally up to whichever chess engine you're running. With GNU Chess 4 tho: first column = the moves, second column = one possible response for each move, and third column = the number of lines in the book that include the move from the first column. If you click this and nothing happens, don't panic 💀 — the engine is either out of its book or just doesn't support this feature at all.
Move Now — forces the chess engine to move right this second, no waiting 💅. Chess engine mode only, so don't try it elsewhere. The Ctrl-M key is the keyboard equivalent. Heads up tho: many engines won't respond to this 🙈.
Retract Move — takes back your last move, no cap 🫶. In chess engine mode, you can only do this after the chess engine has replied to your move — if it's still thinking, use Move Now first. In ICS mode, Retract Move issues the command takeback 1 or takeback 2 depending on whether it is your opponent's move or yours. The Ctrl-X key is a keyboard equivalent.
Recently Used Engines — at the bottom of the engine menu there can be a list of names of engines you recently loaded through the Load Engine menu dialog in previous sessions 👑. Clicking one of those names loads that engine as first engine, so you don't have to go hunting through your (possibly enormous) list of installed engines. The maximum number of displayed engine names is set by the recentEngines command-line option.

🔇 Mute all Sounds

Ticking this menu item toggles all sounds XBoard can make on or off, without losing their definitions 🎀. Like, the vibes go silent but nothing gets deleted. Slay.

⚙️ General Options

The following items to set option values appear in the dialog summoned by the general Options menu item.

Absolute Analysis Scores — controls if scores on the Engine Output window during analysis will be printed from the white or the side-to-move point-of-view 👀.
Almost Always Queen — if this option is on, 7th-rank pawns automatically change into Queens when you pick them up, and when you drag them to the promotion square and release them there, they will promote to that 💖. But when you drag such a pawn backwards first, its identity will start to cycle through the other available pieces. This keeps going until you start to move it forward, at which point the identity of the piece is fixed, so you can safely put it down on the promotion square. If this option is off, what happens depends on the option alwaysPromoteToQueen, which would force promotion to Queen when true. Otherwise XBoard brings up a dialog box whenever you move a pawn to the last rank, asking what piece you want to promote to.
Animate Dragging — if Animate Dragging is on, while you're dragging a piece with the mouse, an image of the piece follows the mouse cursor 🦋. If it's off, there's no visual feedback while you're dragging, but if Animate Moving is on, the move gets animated when it's complete.
Animate Moving — if Animate Moving is on, all piece moves are animated ✨. An image of the piece is shown moving from the old square to the new square when the move is completed (unless the move was already animated by Animate Dragging). If Animate Moving is off, a moved piece instantly disappears from its old square and reappears on its new square when the move is complete. The shifted Ctrl-A key is a keyboard equivalent.
Auto Flag — if this option is on and one player runs out of time before the other, XBoard will automatically call his flag, claiming a win on time ⏰. The shifted Ctrl-F key is a keyboard equivalent. In ICS mode, Auto Flag will only call your opponent's flag, not yours, and the ICS may award you a draw instead of a win if you have insufficient mating material. In local chess engine mode, XBoard may call either player's flag.
Auto Flip View — if the Auto Flip View option is on when you start a game, the board will be automatically oriented so that your pawns move from the bottom of the window towards the top 🔄.

If you are playing a game on an ICS, the board is always oriented at the start of the game so that your pawns move from the bottom of the window towards the top. Otherwise, the starting orientation is determined by the flipView command line option; if it is false (the default), White's pawns move from bottom to top at the start of each game; if it is true, Black's pawns move from bottom to top. See User interface options.

Blindfold — if this option is on, XBoard displays the board as usual but does not display pieces or move highlights 🙈. You can still move in the usual way (with the mouse or by typing moves in ICS mode), even though the pieces are invisible. Main character energy tbh.
Drop Menu — controls if right-clicking the board in crazyhouse / bughouse will pop up a menu to drop a piece on the clicked square (old, deprecated behavior) or allow you to step through an engine PV (new, recommended behavior) 👑.
Enable Variation Trees — if this option is on, playing a move in Edit Game or Analyze mode while keeping the Shift key pressed will start a new variation 🌈. You can then recall the previous line through the Revert menu item. When off, playing a move will truncate the game and append the move irreversibly.
Headers in Engine Output Window — controls the presence of column headers above the variations and associated information printed by the engine, on which you can issue button 3 clicks to open or close the columns 🎀. Available columns are search depth, score, node count, time used, tablebase hits, search speed and selective search depth.
Hide Thinking — if this option is off, the chess engine's notion of the score and best line of play from the current position is displayed as it is thinking 👀. The score indicates how many pawns ahead (or if negative, behind) the chess engine thinks it is. In matches between two machines, the score is prefixed by W or B to indicate whether it is showing White's thinking or Black's, and only the thinking of the engine that is on move is shown. The shifted Ctrl-H key is a keyboard equivalent.
Highlight Last Move — if Highlight Last Move is on, after a move is made, the starting and ending squares remain highlighted 💅. In addition, after you use Backward or Back to Start, the starting and ending squares of the last move to be unmade are highlighted.
Highlight with Arrow — causes the highlighting described in Highlight Last Move to be done by drawing an arrow between the highlighted squares, so that it's visible even when the width of the grid lines is set to zero ➡️.
One-Click Moving — if this option is on, XBoard does not wait for you to click both the from- and the to-square, or drag the piece, but performs a move as soon as it is uniqely specified ⚡. This applies to clicking an own piece that only has a single legal move, clicking an empty square or opponent piece where only one of your pieces can move (or capture) to. Furthermore, a double-click on a piece that can only make a single capture will cause that capture to be made. Promoting a Pawn by clicking its to-square will suppress the promotion popup or other methods for selecting an under-promotion, and make it promote to Queen.
Periodic Updates — if this option is off (or if you're using a chess engine that does not support periodic updates), the analysis window will only be updated when the analysis changes 🕐. If this option is on, the Analysis Window will be updated every two seconds.
Play Move(s) of Clicked PV — if this option is on, right-clicking on the first move of a PV or on the data fields left of it in the Engine Output window during Analyze mode will cause the first move of that PV to be played 🎯. You could also play more than one (or no) PV move by moving the mouse to engage in the PV walk such a right-click will start, to seek out another position along the PV where you want to continue the analysis, before releasing the mouse button. Clicking on later moves of the PV only temporarily show the moves for as long you keep the mouse button down, without adding them to the game.
Ponder Next Move — if this option is off, the chess engine will think only when it is on move 🤔. If the option is on, the engine will also think while waiting for you to make your move. The shifted Ctrl-P key is a keyboard equivalent.
Popup Exit Message — if this option is on, when XBoard wants to display a message just before exiting, it brings up a modal dialog box and waits for you to click OK before exiting 💬. If the option is off, XBoard prints the message to standard error (the terminal) and exits immediately.
Popup Move Errors — if this option is off, when you make an error in moving (such as attempting an illegal move or moving the wrong color piece), the error message is displayed in the message area 😭. If the option is on, move errors are displayed in small pop-up windows like other errors. You can dismiss an error pop-up either by clicking its OK button or by clicking anywhere on the board, including down-clicking to start a move.
Scores in Move List — if this option is on, XBoard will display the depth and score of engine moves in the Move List, in the format of a PGN comment 📝.
Show Coords — if this option is on, XBoard displays algebraic coordinates along the board's left and bottom edges 🔤.
Show Target Squares — if this option is on, all squares a piece that is 'picked up' with the mouse can legally move to are highighted with a fat colored dot in yellow (non-captures) or red (captures) 🔴🟡. Special moves might have other colors (e.g. magenta for promotion, cyan for a partial move). Legality testing must be on for XBoard to know how the piece moves, but with legality testing off some engines would offer this information.

Sticky Windows 💖

Controls whether the auxiliary windows such as Engine Output, Move History and Evaluation Graph should keep touching XBoard's main window when you move the latter. Like, they come with you. Ride or die. 🫶

Test Legality ✨

If this option is on, XBoard tests whether the moves you try to make with the mouse are legal and refuses to let you make an illegal move. The shifted Ctrl-L key is a keyboard equivalent. Moves loaded from a file with Load Game are also checked. If the option is off, all moves are accepted, but if a local chess engine or the ICS is active, they will still reject illegal moves. Turning off this option is useful if you are playing a chess variant with rules that XBoard does not understand. (Bughouse, suicide, and wild variants where the king may castle after starting on the d file are generally supported with Test Legality on.)

Top-Level Dialogs 🪟

Controls whether the auxiliary windows will appear as icons in the task bar and independently controllable, or whether they open and minimize all together with the main window. Group project or solo era — your call bestie.

Flash Moves

Flash Rate ⚡

If this option is non-zero, whenever a move is completed, the moved piece flashes the specified number of times. The flash-rate setting determines how rapidly this flashing occurs. It's giving strobe light, honestly.

Animation Speed 🎬

Determines the duration (in msec) of an animation step, when Animate Moving is switched on.

Zoom factor in Evaluation Graph 📈

Sets the value of the evalZoom option, indicating the factor by which the score interval (-1,1) should be blown up on the vertical axis of the Evaluation Graph. Stretch that graph, queen.

Time Control ⏰

Pops up a sub-menu where you can set the time-control parameters interactively. The shifted Alt+T key is a keyboard equivalent.

classical 🏛️

Selects classical TC, where the game is divided into sessions of a certain number of moves, and after each session the start time is again added to the clocks.

incremental ➕

Selects a TC mode where the game will start with a base time on the clocks, and after every move an 'increment' will be added to it.

fixed max 🧱

Selects a TC mode where you have to make each move within a given time, and any left-over time is not carried over to the next move.

Divide entered times by 60 🍰

To allow entering of sub-minute initial time or sub-second increment, you can tick this checkbox. The initial time can then be entered in seconds, and the increment in units of 1/60 second.

Moves per session 🔁

Sets the duration of a session for classical time control.

Initial time ⏱️

Time initially on the clock in classical or incremental time controls. In classical time controls this time will also be added to the clock at the start of each new session.

Increment or max 🎁

Time to be added to the clock after every move in incremental TC mode. For 'fixed maximum' TC mode, the clock will be set to this time before every move, irrespective of how much was left on that clock.

Time-Odds factors ⚖️

When these options are set to 1 the clocks of the players will be set according to the other specified TC parameters. Players can be given unequal times by specifying a time-odds factor for one of them (or a different factor for both of them). Any time received by that player will then be divided by that factor.

Adjudications ⚖️

Pops up a sub-menu where you can enable or disable various adjudications that XBoard can perform in engine-engine games. The shifted Alt+J key is a keyboard equivalent.

Detect all Mates 🏁

When this option is set XBoard will terminate the game on checkmate or stalemate, even if the engines would not do so. Only works when Test Legality is on.

Verify Engine Result Claims 🔍

When this option is set XBoard will verify engine result claims, (forfeiting engines that make false claims), rather than naively believing the engine. Only works when Test Legality is on.

Draw if Insufficient Mating Material 🤝

When this option is set XBoard will terminate games with a draw result when so little material is left that checkmate is not longer possible. In normal Chess this applies to KK, KNK, KBK and some positions with multiple Bishops all on the same square shade. Only works when Test Legality is on.

Adjudicate Trivial Draws 🥱

When this option is set XBoard will terminate games with a draw result in positions that could only be won against an idiot. In normal Chess this applies to KNNK, KRKR, KBKN, KNKN, and KBKB with Bishops on different square shades. KQKQ will also be adjudicated a draw (possibly unjustly so). Only works when Test Legality is on.

N-Move Rule 🔄

When this option is set to a value different from zero XBoard will terminate games with a draw result after the specified number of reversible moves (i.e. without captures or pawn pushes) is made.

N-fold Repeats 🔂

When this option is set to a value larger than 1, XBoard will terminate games with a draw result when the same position has occurred the specified number of times.

Draw after N Moves Total 🧮

When this option is set to a value different from zero, XBoard will terminate games with a draw result after that many moves have been played. Useful in automated engine-engine matches, to prevent one game between stubborn engines will soak up all your computer time. Facts. Those games go on foreverrr.

Win / Loss Threshold 📊

When this option is set to a value different from zero, XBoard will terminate games as a win when both engines agree the score is above the specified value (interpreted as centi-Pawn) for three successive moves.

Negate Score of Engine #1

Negate Score of Engine #2 🪞

These options should be used with engines that report scores from the white point of view, rather than the side-to-move POV as XBoard would otherwise assume when adjudicating games based on the engine score. When the engine is installed with the extra option firstScoreIsAbs true in the engine list the option would be automatically set when the engine is loaded through the Engine menu, or with the fe or se command-line option.

ICS Options 🌐

Pops up a menu dialog where options can be set that affect playing against an Internet Chess Server.

Auto-Kibitz 💬

Setting this option when playing with or against a chess program on an ICS will cause the last line of thinking output of the engine before its move to be sent to the ICS in a kibitz command. In addition, any kibitz message received through the ICS from an opponent chess program will be diverted to the engine-output window, (and suppressed in the console), where you can play through its PV by right-clicking it.

Auto-Comment 📝

If this option is on, any remarks made on ICS while you are observing or playing a game are recorded as a comment on the current move. This includes remarks made with the ICS commands say, tell, whisper, and kibitz. Limitation: remarks that you type yourself are not recognized; XBoard scans only the output from ICS, not the input you type to it.

Auto-Observe 👀

If this option is on and you add a player to your gnotify list on ICS, XBoard will automatically observe all of that player's games, unless you are doing something else (such as observing or playing a game of your own) when one starts. The games are displayed from the point of view of the player on your gnotify list; that is, his pawns move from the bottom of the window towards the top. Exceptions: If both players in a game are on your gnotify list, if your ICS highlight variable is set to 0, or if the ICS you are using does not properly support observing from Black's point of view, you will see the game from White's point of view.

Auto-Raise Board 🪟

If this option is on, whenever a new game begins, the chessboard window is deiconized (if necessary) and raised to the top of the stack of windows. Main character energy, literally.

Auto Save 💾

If this option is true, at the end of every game XBoard prompts you for a file name and appends a record of the game to the file you specify. Disabled if the saveGameFile command-line option is set, as in that case all games are saved to the specified file. See Load and Save options.

Background Observe while Playing 🕵️

Setting this option will make XBoard suppress display of any boards from observed games while you are playing. Instead the last such board will be remembered, and shown to you when you right-click the board. This allows you to peek at your bughouse partner's game when you want, without disturbing your own game too much.

Dual Board for Background-Observed Game 🪞

Setting this option in combination with Background Observe will display boards of observed games while you are playing on a second board next to that of your own game.

Get Move List 📜

If this option is on, whenever XBoard receives the first board of a new ICS game (or a different game from the one it is currently displaying), it retrieves the list of past moves from the ICS. You can then review the moves with the Forward and Backward commands or save them with Save Game. You might want to turn off this option if you are observing several blitz games at once, to keep from wasting time and network bandwidth fetching the move lists over and over. When you turn this option on from the menu, XBoard immediately fetches the move list of the current game (if any).

Quiet Play 🤫

If this option is on, XBoard will automatically issue an ICS set shout 0 command whenever you start a game and a set shout 1 command whenever you finish one. Thus, you will not be distracted by shouts from other ICS users while playing.

Seek Graph 🔎

Setting this option will cause XBoard to display a graph of currently active seek ads when you left-click the board while idle and logged on to an ICS.

Auto-Refresh Seek Graph

okay so if you also have the Seek Graph option turned on, this one makes the seek graph auto-update itself while it's chillin' on your screen ✨. Small catch though bestie: it only works on FICS and ICC, and it gobbles up a lot of bandwidth on a busy server 💀. Choose wisely.

This one controls whether the ICS Input Box pops up all by itself when you type a printable character to the board window in ICS mode. Very "surprise, I'm here" of it 🎀.

Quit After Game

Controls whether XBoard automatically disconnects from the ICS and closes once the game currently in progress finishes. It's giving "and that's a wrap, goodbye" 👋.

Premove

Premove for White

Premove for Black

First White Move

First Black Move

If Premove is on while you're playing a game on an ICS, you can register your next planned move before it's even your turn — main character foresight, honestly 👑. Move the piece with the mouse the ordinary way, and the starting and ending squares get highlighted in a special color (red by default 🩸). When your turn arrives, if your registered move is legal, XBoard sends it to ICS immediately; if it's not legal, it gets ignored and you can just make a different move. No harm, no foul.

Changed your mind about your premove? Either make a different move, or double-click on any piece to cancel the move entirely. Poof 💨.

You can also enter premoves for the first white and black moves of the game.

Alarm

Alarm Time

When this option is on, an alarm sound plays when your clock counts down to the Alarm Time in an ICS game 🔔. (By default, the time is 5 seconds, but you can specify other values with the Alarm Time spin control.) For games with time controls that include an increment, the alarm will sound each time the clock counts down to the icsAlarmTime. By default, the alarm sound is the terminal bell, but on some systems you can change it to a sound file using the soundIcsAlarm option; see below.

Colorize Messages

Ticking this option makes various types of ICS messages show up with different foreground or background colors in the console 🌈. You can individually select the colors for each type through the accompanying text edits. Aesthetic AND functional? We love to see it.

`-icsMenu` string

The string defines buttons for the ICS text menu. Each button definition consists of two semi-colon-terminated pieces of text — the first giving the label to be written on the button, the second the text that should be sent to the ICS when that button is pressed. This second part (the 'message') can contain linefeeds, so you can send multiple ICS commands with one button. Slay, efficient.

Some messages in the text, all starting with a $-sign, are treated special 👀. When the message contains $input, it will not be sent directly to the ICS, but will be put in the input field of the ICS Chat/Console, with the text cursor at the indicated place, so you can add some text to the message before sending it off. If such a message starts with $add it will be placed behind any text that is already present in the input field, otherwise this field will be cleared first. The word $name occurring in the message will be replaced by the word that was clicked (through button 3) in the ICS Chat/Console.

There are two special messages: $chat will open a new chat with the clicked word in the chat-partner field, while $copy will copy the text that is currently-selected in the ICS Console to the clipboard.

An example of a text menu as it might occur in your settings file (where you could edit it):

-icsMenu {copy;$copy;
list players;who;
list games;games;
finger (player);finger $name;
bullet (player);match $name 1 1 r;
blitz (player);match $name 5 1 r;
rapid (player);match $name 30 0 r;
open chat (player);$chat;
tell (player);tell $name $input;
ask pieces;ptell Please give me a $input;
P;$add Pawn $input;
N;$add Knight $input;
B;$add Bishop $input;
R;$add Rook $input;
Q;$add Queen $input;
}

Tournament Options

Summons a dialog where you can set options important for playing automatic matches between two or more chess programs (e.g. by using the Machine Match menu item in the Mode menu). It's giving tournament director era 🏆.

Tournament file

To run a tournament, XBoard needs a file to record its progress, so it can resume the tourney when it is interrupted. When you want to conduct anything more complex than a simple two-player match with the currently loaded engines — i.e. when you select a list of participants — you must not leave this field blank 🙈.

When you enter the name of an existing tournament file, XBoard will ignore all other input specified in the dialog, and will take the corresponding info from that tournament file. This resumes an interrupted tournament, or adds another XBoard agent playing games for it to those that are already doing so. Specifying a not-yet-existing file will cause XBoard to create it, according to the tournament parameters specified in the rest of the dialog, before it starts the tournament on 'OK'. Provided that you specify participants; without participants no tournament file will be made, but other entered values (e.g. for the file with opening positions) will take effect. Default: configured by the defaultTourneyName option.

Sync after round / Sync after cycle

The sync options, when on, will cause WinBoard to refrain from starting games of the next round or cycle before all games of the previous round or cycle are finished. This guarantees correct ordering in the games file, even when multiple XBoard instances are concurrently playing games for the same tourney. Default: sync after cycle, but not after round.

Select Engine / Tourney participants

From the Select Engine listbox you can pick an engine from your list of engines registered in the settings file, to be added to the tournament. The engines selected so far will be listed in the 'Tourney participants' memo. The latter is a normal text edit, so you can use normal text-editing functions to delete engines you selected accidentally, or change their order. Typing names here yourself is not recommended, because names that do not exactly match one of the names from the selection listbox will lead to undefined behavior ⚠️.

Tourney type

Here you can specify the type of tournament you want. XBoard's intrinsic tournament manager support round-robins (type = 0), where each participant plays every other participant, and (multi-)gauntlets, where one (or a few) so-called 'gauntlet engines' play an independent set of opponents. In the latter case, you specify the number of gauntlet engines. E.g. if you specified 10 engines, and tourney type = 2, the first 2 engines each play the remaining 8. A value of -1 instructs XBoard to play Swiss; for this to work an external pairing engine must be specified through the pairingEngine option. Each Swiss round will be considered a tourney cycle in that case. Default: 0.

Number of tourney cycles / Default Number of Games in Match

You can specify tourneys where every two opponents play each other multiple times. Such multiple games can be played in a row, as specified by the 'number of games per pairing', or by repeating the entire tournament schedule a number of times (specified by the 'number of tourney cycles'). The total number of times two engines meet will be the product of these two. Default is 1 cycle; the number of games per pairing is the same as the default number of match games, stored in your settings file through the defaultMatchGames option.

Pause between Match Games

Time (in milliseconds) XBoard waits before starting a new game after a previous match or tournament game finishes ⏸️. Such a waiting period is important for engines that do not support 'ping', as these sometimes still produce a move long after the game finished because of the opponent resigning, which would be mistaken for a move in the next game if that had already started. Messy. We avoid 😭.

Save Tourney Games on

File where the tournament games are saved (duplicate of the item in the Save Game Options).

Game File with Opening Lines / File with Start Positions / Game Number / Position Number / Rewind Index after this many Games

These items optionally specify the file with move sequences or board positions the tourney games should start from. The corresponding numbers specify the number of the game or position in the file. Here a value -1 means automatic stepping through all games on the file, -2 automatic stepping every two games. The Rewind-Index parameter causes a stepping index to reset to one after reaching a specified value.

A setting of -2 for the game number will also be effective in a tournament without specifying a game file, but playing from the GUI book instead. In this case the first (odd) games will randomly select from the book, but the second (even) games will select the same moves from the book as the previous game. (Note this leads to the same opening only if both engines use the GUI book!) Default: No game or position file will be used. The default index if such a file is used is 1.

Disable own engine books by default

Setting this option reverses the default situation for use of the GUI opening book in tournaments from what it normally is, namely not using it. So unless the engine is installed with an option to explicitly specify it should not use the GUI book (i.e. -firstHasOwnBookUCI true), it will be made to use the GUI book. Sneaky little flip 📚✨.

Replace Engine

Upgrade Engine

okay so bestie, these two buttons are your tournament glow-up tools 💅 They let you swap out the actual participants of a tournament that's already running. Here's the vibe: open the Match Options dialog on an XBoard that's playing for the tourney, and boom — all the tourney parameters show up right there in the dialog fields. Then you just edit the name of one engine into the name of another by editing the participants field.

🚨 But preserve the order of the others! Do not shuffle, do not reorder, do not get creative. The order matters, fr fr.

Once you've done that, hit the button and the substitution happens:

Upgrade Engine — the substitution only affects future games. Clean, low drama, no retroactive chaos.
Replace Engine — the substitution is retroactive: every game the substituted engine already played gets invalidated, and they get replayed with the substitute engine instead. ✨

In that second case the engine must not be playing when you do this. But otherwise? No need to pause the tournament play at all to make a substitution. Slay. 👑

Clone Tourney

Press this button after you've specified an existing tournament file and it will copy the contents of that file into the dialog, and then put the originally proposed name for the tourney file back. 🎀 Then you can run a tourney with the same parameters by pressing OK — possibly after changing the proposed name of the tourney file for the new tourney. Iconic little copy-paste moment, ngl.

Continue Later

Pressing the Continue Later button confirms the current value of all items in the dialog and closes it — but it will not automatically start the tournament. Why would you want this? So you can come back to the dialog later without losing all the settings you already typed in, and adjust parameters through other menu dialogs in the meantime. 🦋

(And FYI, the Common Engine Setting, Time Control and General Options dialogs can be accessed without closing the Tournament Options dialog, through the respective buttons at the bottom of the latter. Convenience queen.)

✨ Load Game Options ✨

Summons a dialog where you can set the options that control how games get loaded. 🍓

Auto-Display Tags

Setting this option causes a window to pop up when you load a game, showing you the PGN Tags for that game. Very "receipts on arrival".

Auto-Display Comment

Setting this option causes a window to pop up whenever there's a comment to (or a variation on) the currently displayed move. 💬

Auto-Play speed of loaded games

This sets the number of seconds between moves when a newly loaded game is auto-playing. A decimal fraction on the number is understood, because we're precise like that. Then:

Set it to -1 and auto-play is disabled — you just stay in the start position of the game after the loading completes.
Set it to 0 and it will instantly jump to the final position of the game. 💀

The Auto-Play speed is also used to determine the analysis time for each move during Analyze Game. And note that auto-playing (including game analysis) can be stopped at any time through the P button above the board. 🫶

options to use in game-viewer mode

Specifies the options that get automatically set when XBoard is invoked with the -viewer option on its command line — which is exactly what happens when it's started in response to you clicking a PGN game file. 📂

The default setting would start XBoard without an engine (due to the -ncp option). But if you want it to automatically start with your favorite engine and automatically start analyzing, you could include the necessary options for that right here, e.g. -fe <engine> -initialMode analysis.

Thresholds for position filtering in game list

The following options can be set to limit the display of games in the Game List window down to a sub-set that meets the specified criteria. Narrowing the field, as one does. 🔍

Elo of strongest player at least

Elo of weakest player at least

Games with an Elo tag specifying a lower rating for the mentioned player will not be displayed in the Game List. Bye. 🙈

No games before year

Games with a Date tag before the specified year will not be displayed in the Game List. Ancient history stays in the archives.

Final nr of pieces

A single number, or a range (like 8-10), can be entered here. Only games where the number of men in the final position falls inside the given range will be displayed in the Game List.

Minimum nr consecutive positions

Specifies for how many consecutive positions the more fuzzy position-matching criteria have to be satisfied in order to count as a match. Consistency check, basically. ⭐

Search mode

find position

XBoard can select games for display in the Game List based on whether they contain a position matching the position currently displayed on the board — that's in addition to the conditions on the PGN tags — by pressing the find position or narrow buttons in the Game List window. The Search mode setting determines what actually counts as a match. Your options, bestie:

an exact match,
a position that has all shown material in the same place, but might contain additional material,
a position that has all Pawns in the same place, but can have the shown material anywhere,
a position that can have all shown material anywhere,
or a position that has material between certain limits anywhere.

For that last one you have to place the material that must minimally be present in the four lowest ranks of the board, and the optional additional material in the four highest ranks of the board. You can also request the optional material to be balanced — i.e. equal for white and black. ⚖️

narrow

The narrow button is similar in function to the find position button, but it only searches in the games you've already selected rather than the complete game file. Which means you can use it to refine a search based on multiple criteria. Layering, chef's kiss. 🎀

Also match reversed colors

Also match left-right flipped position

When you're looking for matching positions rather than matching by material, these settings determine whether mirror images also count as a match — that's a vertical flip combined with a color reversal, for the first one. The left-right flipping is only useful after all castling rights have expired (or in Xiangqi). 🦋

💖 Save Game Options 💖

Summons a dialog where you can specify whether XBoard should automatically save files of games when they finish, and where and how it should do that.

Auto-Save Games

When set, XBoard will automatically save games to a file as they finish. (Not when you abort them by pressing New Game, though!) It will either prompt you for a filename, or use the file specified by the saveGameFile option. 🔥

Own Games Only

Setting this option will exclude games by others observed on an Internet Chess Server from automatic saving. Your file, your games, your rules. 💅

Save Games on File

The name of the file on which games should be saved automatically. Games are always appended to the file, and will never overwrite anything. No accidental deletions in this house.

Save Final Position on File

When a name is defined here, the final position of each game is appended to the mentioned file. 📌

PGN Event Header

Specifies the name of the event used in the PGN event tag of new games that you create. Branding, basically. ✨

Old Save Style

Saves games in an obsolete and now long forgotten format, rather than as PGN.

💀 Never use this for orthodox Chess! Like, never never.

Include Number Tag in tourney PGN

When on, this option will cause the non-standard 'Number' tag to be written in any game saved in PGN format. It will contain the unique number of the game in the tourney. (As opposed to the 'Round' tag, which can be shared by many games.) 🔢

Save Score/Depth Info in PGN

When on, this option will cause the score and the depth at which it was calculated by an engine — and, when available, the thinking time — to be saved with the move as a comment to the move, in the format {score/depth time}. Here score is in pawn units from the point of view of the player that made the move, with two digits behind the decimal Pawn. 📊

Save Out-of-Book Info in PGN

When on, this option causes the score of the first move the engine made after coming out of book to be put in an 'Annotator' PGN tag. 🎯

🌈 Game List 🌈

Pops up a dialog where you can select the PGN tags that should appear on the lines in the Game List, and also decide their order. Customize your lil dashboard, bestie. 🎀

🎵 Sound Options 🎵

Summons a dialog where you can specify the sounds that should accompany the various events that can occur in XBoard. Most of these events are only relevant to ICS play, but the move sound is an important exception. For each event listed in the dialog, you can select a standard sound from a menu. 🔊

Sound Program

Specifies the command XBoard should invoke to play sounds. The specified text will be suffixed by the name of the sound file, and then run as a command.

Sounds Directory

Specifies the directory where XBoard will look for files with the names of the standard sounds. 📁

User WAV File

When you type a filename here, it can be assigned to the events by selecting Above WAV File from the drop downs. 🎶

Try-Out Sound

Play

The 'event' that triggers the Try-Out sound is you pressing the Play button behind it. This lets you judge the sounds. Audition era. 👑

👑 Save Settings Now 👑

Selecting this menu item causes the current XBoard settings to be written to the settings file (.xboardrc in your home directory), so they'll also apply in future sessions. 💾

But heads up: some settings are 'volatile' and are not saved, because XBoard considers it too unlikely that you'd want those to apply next time. In particular this applies to:

the Chess program, and all options giving information on those Chess programs (such as their directory, if they have their own opening book, if they are UCI or native XBoard),
or the variant you are playing.

Such options would still be understood when they appear in the settings file in case they were put there with the aid of a text editor — but they would disappear from the file as soon as you save the settings. 🙈

Also note that XBoard no longer pays attention to option values specified in the .Xresources file. (Specifying key bindings there will still work, though. 🫶)

To alter the default of volatile options, you can use the following method: rename your ~/.xboardrc settings file (to ~/.yboardrc, say), and create a new file ~/.xboardrc which only contains the options

    -settingsFile  ~/.yboardrc
    -saveSettingsFile  ~/.yboardrc

This will cause your settings to be saved on ~/.yboardrc in the future, so that ~/.xboardrc is no longer overwritten. You can then safely specify volatile options in ~/.xboardrc, either before or after the settingsFile options. Note that when you specify persistent options after the settingsFile options in this ~/.xboardrc, you will essentially turn them into volatile options with the specified value as default, because that value will overrule the value loaded from the settings file (being read later). 💅

Save Settings on Exit

Setting this option has no immediate effect, but causes the settings to be saved when you quit XBoard. What happens then is otherwise identical to what happens when you use select "Save Settings Now", see there. 👑

Info XBoard — Displays the XBoard documentation in info format. For this feature to work, you must have the GNU info program installed on your system, and the file xboard.info must either be present in the current working directory, or have been installed by the make install command when you built XBoard. 📖
Man XBoard — Displays the XBoard documentation in man page format. The F1 key is a keyboard equivalent. For this feature to work, the file xboard.6 must have been installed by the make install command when you built XBoard, and the directory it was placed in must be on the search path for your system's man command.
About XBoard — Shows the current XBoard version number. ⭐

Other Shortcut Keys

Show Last Move — By hitting Enter the last move will be re-animated. ✨
Load Next Game — Loads the next game from the last game record file you loaded. The Alt+PgDn key triggers this action.
Load Previous Game — Loads the previous game from the last game record file you loaded. The Alt+PgUp key triggers this action. Not available if the last game was loaded from a pipe. 🚫
Reload Same Game — Reloads the last game you loaded. Not available if the last game was loaded from a pipe. Currently no keystroke is assigned to this ReloadGameProc.
Reload Same Position — Reloads the last position you loaded. Not available if the last position was loaded from a pipe. Currently no keystroke is assigned to this ReloadPositionProc.

In the Xaw build of XBoard you can add or remove shortcut keys using the X resources paneA.translations. Here is an example of what could go into your .Xdefaults file:

XBoard*paneA.translations: \
  Shift<Key>?: MenuItem(Help.About) \n\
  Ctrl<Key>y: MenuItem(Action.Accept) \n\
  Ctrl<Key>n: MenuItem(Action.Decline) \n\
  Ctrl<Key>i: MenuItem(Nothing)

So the key should always be bound to the action 'MenuItem', with the (hierarchical) name of the menu item as argument. There are a few actions available for which no menu item exists: Binding a key to Nothing makes it do nothing, thus removing it as a shortcut key. Other such functions that can be bound to keys are:

AboutGame, DebugProc (switches the -debug option on or off),
LoadNextGame, LoadPrevGame, ReloadGame, ReloadPosition.

✨ OPTIONS ✨

This section documents the command-line options to XBoard. You can set these options in two ways: by typing them on the shell command line you use to start XBoard, or by editing the settings file (usually ~/.xboardrc) to alter the value of the setting that was saved there. Some of the options cannot be changed while XBoard is running; others set the initial state of items that can be changed with the Options menu. 🎀

Most of the options have both a long name and a short name. To turn a boolean option on or off from the command line, either give its long name followed by the value true or false (-longOptionName true), or give just the short name to turn the option on (-opt), or the short name preceded by x to turn the option off (-xopt). For options that take strings or numbers as values, you can use the long or short option names interchangeably. 💖

Chess Engine Options

-tc or -timeControl minutes[:seconds] — Each player begins with his clock set to the timeControl period. Default: 5 minutes. The additional options movesPerSession and timeIncrement are mutually exclusive. ⏰
-mps or -movesPerSession moves — When both players have made movesPerSession moves, a new timeControl period is added to both clocks. Default: 40 moves.
-inc or -timeIncrement seconds — If this option is specified, movesPerSession is ignored. Instead, after each player's move, timeIncrement seconds are added to his clock. Use -inc 0 if you want to require the entire game to be played in one timeControl period, with no increment. Default: -1, which specifies movesPerSession mode. 🌸
-clock/-xclock or -clockMode true/false — Determines whether or not to display the chess clocks. If clockMode is false, the clocks are not shown, but the side that is to play next is still highlighted. Also, unless searchTime is set, the chess engine still keeps track of the clock time and uses it to determine how fast to make its moves. 🕐
-shoMoveTime true/false — When this option is set the time that has been thought about the current move will be displayed behind the remaining time in parentheses (in seconds). Default: false.
-st or -searchTime minutes[:seconds] — Tells the chess engine to spend at most the given amount of time searching for each of its moves. Without this option, the chess engine chooses its search time based on the number of moves and amount of time remaining until the next time control. Setting this option also sets clockMode to false. 🔥
-depth or -searchDepth number — Tells the chess engine to look ahead at most the given number of moves when searching for a move to make. Without this option, the chess engine chooses its search depth based on the number of moves and amount of time remaining until the next time control. With the option, the engine will cut off its search early if it reaches the specified depth.
-firstNPS number
-secondNPS number — Tells the chess engine to use an internal time standard based on its node count, rather then wall-clock time, to make its timing decisions. The time in virtual seconds should be obtained by dividing the node count through the given number, like the number was a rate in nodes per second. Xboard will manage the clocks in accordance with this, relying on the number of nodes reported by the engine in its thinking output. If the given number equals zero, it can obviously not be used to convert nodes to seconds, and the time reported by the engine is used to decrement the XBoard clock in stead. The engine is supposed to report in CPU time it uses, rather than wall-clock time, in this mode. This option can provide fairer conditions for engine-engine matches on heavily loaded machines, or with very fast games (where the wall clock is too inaccurate). showThinking must be on for this option to work. Default: -1 (off). Not many engines might support this yet! 😭
-firstTimeOdds factor
-secondTimeOdds factor — Reduces the time given to the mentioned engine by the given factor. If pondering is off, the effect is indistinguishable from what would happen if the engine was running on an n-times slower machine. Default: 1.
-timeOddsMode mode — This option determines how the case is handled where both engines have a time-odds handicap. If mode=1, the engine that gets the most time will always get the nominal time, as specified by the time-control options, and its opponent's time is renormalized accordingly. If mode=0, both play with reduced time. Default: 0.
-hideThinkingFromHuman true/false — Controls the Hide Thinking option. See Options Menu. Default: true. (Replaces the Show-Thinking option of older xboard versions.) 🙈
-thinking/-xthinking or -showThinking true/false — Forces the engine to send thinking output to xboard. Used to be the only way to control if thinking output was displayed in older xboard versions, but as the thinking output in xboard 4.3 is also used for several other purposes (adjudication, storing in PGN file) the display of it is now controlled by the new option Hide Thinking. See Options Menu. Default: false. (But if xboard needs the thinking output for some purpose, it makes the engine send it despite the setting of this option.)
-ponder/-xponder or -ponderNextMove true/false — Sets the Ponder Next Move menu option. See Options Menu. Default: true.
-smpCores number — Specifies the maximum number of CPUs an SMP engine is allowed to use. Only works for engines that support the XBoard/WinBoard-protocol cores feature. 👑
-mg or -matchGames n — Automatically runs an n-game match between two chess engines, with alternating colors. If the loadGameFile or loadPositionFile option is set, XBoard starts each game with the given opening moves or the given position; otherwise, the games start with the standard initial chess position. If the saveGameFile option is set, a move record for the match is appended to the specified file. If the savePositionFile option is set, the final position reached in each game of the match is appended to the specified file. When the match is over, XBoard displays the match score and exits. Default: 0 (do not run a match). 🔥
-mm/-xmm or -matchMode true/false — Setting matchMode to true is equivalent to setting matchGames to 1.
-sameColorGames n — Automatically runs an n-game match between two chess engines, without alternating colors. Otherwise the same applies as for the -matchGames option, over which it takes precedence if both are specified. (See there.) Default: 0 (do not run a match). 🌈
-epd — bestie, this one flips XBoard into EPD test-suite solving mode for the entire session. Games get aborted after a single move, and that move gets compared against the best-move or avoid-move from the EPD position description the "game" started from. Playing a best move = a win 🏆, playing an avoid move = a loss 💀, and playing literally anything else = a draw 🤝. Run this alongside match mode, plus an EPD file of starting positions with an auto-incrementing index. Color assignment goes so that the first engine plays all the moves and the second engine is never involved, periodt. Results for each position — and the time used solving them — get reported in the lower pane of the Engine Output window. ✨
-fcp or -firstChessProgram program, -scp or -secondChessProgram program — the names of your first and second chess engines respectively. Heads up: a second engine only gets started in Two Machines (match) mode, or in Analyze mode with two engines. The second engine defaults to being the same as the first. Default for the first engine: fairymax.
-fe or -firstEngine nickname, -se or -secondEngine nickname — a whole alternative to fcp and scp for specifying your engines, designed for engines you already registered via the Load Engine dialog in XBoard's settings file. It doesn't just grab the real name of the engine, it also pulls in all the options configured with it. (Like, if it's UCI, whether it should use book.) iykyk 🫶
-fb, -xfb or -firstPlaysBlack true/false — in games between two engines, firstChessProgram normally plays white. Set this true and it plays black instead. In a multi-game match, this only affects the colors for the first game — they still alternate in the subsequent ones.
-fh or -firstHost host, -sh or -secondHost host — the hosts your engines run on. Default for each is localhost. Specify another host and XBoard uses rsh to run the engine over there. (You can swap in a different remote shell program for rsh using the remoteShell option described below.) 🌐
-fd or -firstDirectory dir, -sd or -secondDirectory dir — the working directories the engines get run in. Default is "", which means run the engine in the same working directory as XBoard itself. (See the CHESSDIR environment variable.) Lowkey important: this only works when the engine is running on the local host — it does not work if the engine runs remotely via the -fh or -sh option. 😭
-initString string or -firstInitString, -secondInitString string — the string sent to initialize each engine for a new game. Default:

new
random

Setting this from the command line is tricky, bestie, because you have to type real newline characters, including one at the very end. In most shells you do that by entering a \ character followed by a newline. Using the character sequence \n in the string should work too, though.

If you change this option, don't remove the new command — it's required by all chess engines to start a new game.

You can remove the random command if you want; including it causes GNU Chess 4 to randomize its move selection slightly so it doesn't play the same moves in every game. Even without random, GNU Chess 4 randomizes its choice of moves from its opening book. Many other engines ignore this command entirely and always (or never) randomize.

You can also try adding other commands to the initString; see the documentation of whatever engine you're using for the deets.

-firstComputerString string, -secondComputerString string — the string sent to the engine if its opponent is another computer chess engine. Default is computer\n. Probably the only useful alternative is the empty string (''), which keeps the engine from knowing it's playing another computer. 🙈
-reuse, -xreuse or -reuseFirst true/false, -reuse2, -xreuse2 or -reuseSecond true/false — set it false and XBoard kills off the engine after every single game and starts it fresh for the next one. Set it true (that's the default) and XBoard starts the engine just once and reuses it for multiple games. Some old engines may not work properly with reuse turned on, but otherwise games start faster if you leave it on. ✨
-firstProtocolVersion version-number, -secondProtocolVersion version-number — which version of the chess engine communication protocol to use. By default, version-number is 2. In version 1, the "protover" command is not sent to the engine; since version 1 is a subset of version 2, nothing else changes. Other values for version-number are not supported. 🚫
-firstScoreAbs true/false, -secondScoreAbs true/false — set this and the score reported by the engine is taken to be the one in favor of white, even when the engine plays black. Important when XBoard uses the score for adjudications, or in PGN reporting.
-niceEngines priority — lets you lower the priority of the engine processes, so the generally insatiable hunger for CPU time that chess engines have doesn't interfere so much with smooth operation of XBoard (or the rest of your system). Negative values could increase the engine priority, which is not recommended.
-firstOptions string, -secondOptions string — the given string is a comma-separated list of (option name=option value) pairs, like this example: "style=Karpov,blunder rate=0". If an option announced by the engine at startup through the feature commands of the XBoard/WinBoard protocol matches one of the option names (i.e. "style" or "blunder rate"), it gets set to the given value (i.e. "Karpov" or 0) through a corresponding option command to the engine. All this provided the type of the value (text or numeric) matches as well. 💅
-firstNeedsNoncompliantFEN string, -secondNeedsNoncompliantFEN string — the castling rights and e.p. fields of the FEN sent to the mentioned engine with the setboard command get replaced by the given string. You could use this to run engines that don't understand Chess960 FENs in variant fischerandom, making them at least understand the opening position, by setting the string to "KQkq -". (Note you also have to give the e.p. field!) Other possible uses: workarounds for engines that want to see castling and e.p. fields in variants that don't have castling or e.p. (shatranj, courier, xiangqi, shogi) so that XBoard would normally omit them (string = "- -"), or to add variant-specific fields not yet supported by XBoard (e.g. to indicate the number of checks in 3check).
-shuffleOpenings — forces shuffling of the opening setup in variants that normally have a fixed initial position. The shufflings are symmetric for black and white, and exempt King and Rooks in variants with normal castling. Stays in force until a new variant is selected. 🎲
-fischerCastling — specifies that Fischer castling (as in Chess960) should be enabled in variants that normally would not have it. Remains in force until a new variant is selected.

👑 UCI + WB Engine Settings 👑

-fUCI or -firstIsUCI true/false, -sUCI or -secondIsUCI true/false — says whether the mentioned engine executable file is a UCI engine, and should be run with the aid of the Polyglot adapter rather than directly. XBoard then passes the other UCI options and the engine name to Polyglot on its command line, according to the option adapterCommand.
-fUCCI, -sUCCI, -fUSI, -sUSI — options similar to fUCI and sUCI, except they use the indicated engine with the protocol adapter specified in the uxiAdapter option. You can configure that for running a UCCI or USI adapter, as the need arises. 🦋
-adapterCommand string — the string holds the command XBoard should issue to start an engine that comes with the fUCI option. Any identifier following a percent sign in the command (e.g. %fcp) gets treated as the name of an XBoard option, and replaced by that option's value at the time the engine is started. For starting the second engine, any leading "f" or "first" in the option name gets replaced by "s" or "second" first, before its value is found. Default: 'polyglot -noini -ec "%fcp" -ed "%fd"'
-uxiAdapter string — similar to adapterCommand, but used for engines accompanied by the fUCCI or fUSI option, so you can configure XBoard to be ready to handle more than one flavor of non-native protocols. Default: ""
-polyglotDir filename — the name of the directory where the Polyglot adapter for UCI engines lives. Default: "".
-usePolyglotBook true/false — specifies whether the Polyglot book should be used as the GUI book.
-polyglotBook filename — the filename of the opening book. The book is only used when the usePolyglotBook option is set to true, and the option firstHasOwnBookUCI or secondHasOwnBookUCI applying to the engine is set to false. The engine gets kept in force mode as long as the current position is in book, and XBoard selects the book moves for it. Default: "".
-fNoOwnBookUCI or -firstXBook or -firstHasOwnBookUCI true/false, -sNoOwnBookUCI or -secondXBook or -secondHasOwnBookUCI true/false — indicates whether the mentioned engine has its own opening book it should play from, rather than using the external book through XBoard. Default: depends on the setting of the option discourageOwnBooks. 📚
-discourageOwnBooks true/false — okay so when this is turned on, any engine you load fresh is assumed to be using the GUI book unless it says otherwise out loud. If you don't set it, they're assumed to NOT use the GUI book unless they specify differently (like with firstXBook). Default: false. 🎀
-bookDepth n — caps how much the GUI book gets used, only for the first n moves of each side. Default: 12. ✨
-bookVariation n — a value n from 0 to 100 that tunes how the GUI books pick moves, all the way from totally random to best-only. Default: 50. 💅
-mcBookMode — bestie, this is a volatile option and it's lowkey iconic. When you specify it, the probing algorithm of the GUI book gets altered so it always picks the move that's most under-represented based on its performance. Once all moves have been played in roughly the right proportion, a book miss gets reported, so the engine gets a chance to go explore a new move. On top of that, the score of the moves gets tracked during the session in a book buffer. If you play a match in this mode, you basically build a book from scratch, fr fr. The only output is the saved games, which you can convert into an actual book later with the Save Games as Book command. That same command can also pre-fill the book buffer before you add new games based on the probing algorithm. 🧚
-fn string or -firstPgnName string
-sn string or -secondPgnName string

These tell XBoard what name to use for the engine in the PGN tags of engine-engine games. The whole point is letting you install different versions of the same engine with different settings and still tell them apart. Default: "". 👑

-defaultHashSize n — sets the hash table size to n MegaBytes. Together with the EGTB cache size, this number also gets used to calculate the memory setting of XBoard/WinBoard engines — for the ones that support the memory feature of the XBoard/WinBoard protocol, anyway. Default: 64. 💾
-defaultCacheSizeEGTB n — sets the EGTB cache size to n MegaBytes. Together with the hash-table size, this number also gets used to calculate the memory setting of XBoard/WinBoard engines, again for those that support the memory feature of the XBoard/WinBoard protocol. Default: 4. 🌸
-defaultPathEGTB filename — gives the name of the directory where the end-game tablebases live, for UCI engines. Default: "/usr/local/share/egtb". 🗂️
-egtFormats string — tells XBoard which end-game tables are installed on the computer, and where. The argument is a comma-separated list of format specifications, and each specification is a format name, a colon, and a directory path name, like "nalimov:/usr/local/share/egtb". If the name part matches a format the engine asks for through a feature command, xboard relays the path name for that format to the engine through an egtpath command. One egtpath command gets sent for each matching format. The popular formats are "nalimov" and "gaviota" DTM tablebases, syzygy DTZ tablebases and "scorpio" bitbases. Default: "". 🌈
-firstChessProgramNames={names} — this one lets you customize the listbox with chess-engine names that shows up in the Load Engine and Tournament Options dialog. It's a list of strings, one per line. When an engine gets loaded, the matching line gets prefixed with -fcp and processed like it just showed up on the command line. Which means — apart from the engine command — it can contain any number of XBoard options you want to use with that engine. (The commonly used ones here are -fd, -firstXBook, -fUCI, -variant.)

The value of this option gets gradually built up as you load new engines through the Load Engine menu dialog with Add to list ticked. Wanna change it some other way (deleting engines, say)? Use the menu item Edit Engine List in the Engine menu. 💖

🏆 Tournament options 🏆

-defaultMatchGames n — sets how many games a match between two engines started from the menu will be, to n. It also gets used as games per pairing in other tournament formats. Default: 10. ✨
-matchPause n — specifies the duration of the pause between two games of a match or tournament between engines, as n milliseconds. Engines that don't support ping especially need this, so that the move they're thinking about when an opponent unexpectedly resigns doesn't get counted for the next game (which would lead to illegal moves over there 😭). Default: 10000. 💅
-tf filename or -tourneyFile filename — specifies the name of the tournament file used in match mode to run a multi-player tournament. This file is a special settings file that stores the description of the tournament (progress info included) through normal options (time control, load and save files, etc.) and through some special-purpose options listed below. 🎀
-tt number or -tourneyType number — specifies the type of tourney: 0 = round-robin, N>0 = (multi-)gauntlet with N gauntlet engines, -1 = Swiss through external pairing engine. Volatile option, but stored in tourney file. 🌟
-cy number or -tourneyCycles number — specifies the number of cycles in a tourney. Volatile option, but stored in tourney file. 🔁
-participants list — the list is a multi-line text string that specifies engines occurring in the firstChesProgramNames list in the settings file by their (implied or explicitly given) nicknames, one engine per line. The engines you mention will play in the tourney. Volatile option, but stored in tourney file. 👑
-results string — the string of +=- characters lists the result of all played games in a tourney. Games currently playing get listed as *, while a space means a game that hasn't been played yet. Volatile option, but stored in tourney file. 📊
-defaultTourneyName string — specifies the name of the tournament file XBoard should propose when the Match Options dialog gets opened. Any %y, %M, %d, %h, %m, %s in the string get replaced by the current year, month, day of the month, hours, minutes, seconds of the current time, respectively, as two-digit numbers. A %Y would get replaced by the year as a 4-digit number. Default: empty string. 🕰️
-pairingEngine filename — specifies the external program to use to pair the participants in Swiss tourneys. XBoard talks to this engine the same way it talks to Chess engines. The only commands sent to the pairing engine are results N string (where N is the number of participants and string the results so far in the format of the results option) and pairing N (where N is the number of the tourney game). To the latter, the pairing engine should answer with A-B, where A and B are participant numbers (in the range 1-N). (There should be no reply to the results command.) Default: empty string. 🧩
-afterGame string
-afterTourney string

When non-empty, the given string gets executed as a system command after each tournament game, or after the tourney completes, respectively. You could use this, for example, to automatically run a cross-table generator on the PGN file where games are saved, to update the tourney standings. Default: "". 🔥

-syncAfterRound true/false
-syncAfterCycle true/false

Controls whether different instances of XBoard concurrently running the same tournament will wait for each other. Defaults: sync after cycle, but not after round. 🫶

-seedBase number — used to store the seed of the pseudo-random-number generator in the tourneyFile, so that separate instances of XBoard working on the same tourney can take coherent 'random' decisions, like picking an opening for a given game number. 🎲

🌐 ICS options 🌐

-ics / -xics or -internetChessServerMode true/false — connect with an Internet Chess Server to play chess against its other users, watch games they're playing, or review games that recently finished. Default: false. 💻
-icshost or -internetChessServerHost host — the Internet host name or address of the chess server to connect to when in ICS mode. Default: chessclub.com. Another popular chess server to try is freechess.org. If your site doesn't have a working Internet name server, try specifying the host address in numeric form. You may also need to specify the numeric address when using the icshelper option with timestamp or timeseal (see below). 🛰️
-icsport or -internetChessServerPort port-number — the port number to use when connecting to a chess server in ICS mode. Default: 5000. 🔌
-icshelper or -internetChessServerHelper prog-name — an external helper program used to communicate with the chess server. You'd set it to "timestamp" for ICC (chessclub.com) or "timeseal" for FICS (freechess.org), after getting the correct version of timestamp or timeseal for your computer. See "help timestamp" on ICC and "help timeseal" on FICS. This option is shorthand for -useTelnet -telnetProgram program. 🧚
-telnet / -xtelnet or -useTelnet true/false — okay, this option is poorly named; it should be called useHelper. If set to true, it tells XBoard to run an external program to communicate with the Internet Chess Server. The program to use is given by the telnetProgram option. If the option is false (the default), XBoard opens a TCP socket and uses its own internal implementation of the telnet protocol to communicate with the ICS. See Firewalls. 🔥
-telnetProgram prog-name — also poorly named; it should be called helperProgram. It gives the name of the telnet program to be used with the gateway and useTelnet options. The default is telnet. The telnet program gets invoked with the value of internetChessServerHost as its first argument and the value of internetChessServerPort as its second argument. See Firewalls. 🚪
-gateway host-name — set this to a host name and XBoard stops doing its own lil internal telnet thing and instead talks to the Internet Chess Server by running rsh to fire up the telnetProgram on that host. You can swap in a different remote shell program instead of rsh using the remoteShell option (it's described below, bestie, keep scrolling 💅). Also: see Firewalls.
-internetChessServerCommPort or -icscomm dev-name — set this and XBoard chats with the ICS through whatever character I/O device you name, instead of opening a TCP connection. Use it when your system literally has no kind of Internet connection of its own (not even SLIP or PPP 😭) but you do have dial-up access (or a hardwired terminal line) to an Internet service provider that you can telnet to the ICS from.

The support for this option in XBoard is minimal, fr fr. You gotta set all the communication parameters and tty modes before you enter XBoard. 👑

Use a script kinda like this:

    stty raw -echo 9600 > /dev/tty00
    xboard -ics -icscomm /dev/tty00

Here you replace /dev/tty00 with the name of the device your modem is hooked up to. You might have to add several more options to those stty commands. Check the man pages for stty and tty if you run into problems. Also, on many systems stty works on its standard input instead of standard output, so you have to use < instead of >. 💀

If you're on linux, try starting with the script below. Change it as necessary for your installation.

#!/bin/sh -f
# configure modem and fire up XBoard

# configure modem
(
  stty 2400 ; stty raw ; stty hupcl ; stty -clocal
  stty ignbrk ; stty ignpar ; stty ixon ; stty ixoff
  stty -iexten ; stty -echo
) < /dev/modem
xboard -ics -icscomm /dev/modem

After you start XBoard this way, type whatever commands are necessary to dial out to your Internet provider and log in. Then telnet to ICS, using a command like telnet chessclub.com 5000. Important: see the paragraph below about extra echoes, in Limitations.

-icslogon or -internetChessServerLogonScript file-name — whenever XBoard connects to the Internet Chess Server, if it finds a file with the name you gave in this option, it feeds that file's contents to the ICS as commands. The default file name is .icsrc. Usually the first two lines of the file should be your ICS user name and password. The file can live either in $CHESSDIR, in XBoard's working directory if CHESSDIR is not set, or in your home directory. 🏠
-msLoginDelay delay — if you're having trouble logging on to an ICS while using the -icslogon option, sneaking some delay between characters of the logon script may help. This option adds delay milliseconds of delay between characters. Good values to try are 100 and 250. ✨
-icsinput/-xicsinput or -internetChessServerInputBox true/false — sets the ICS Input Box menu option. See Mode Menu. Default: false.
-autocomm/-xautocomm or -autoComment true/false — sets the Auto Comment menu option. See Options Menu. Default: false.
-autoflag/-xautoflag or -autoCallFlag true/false — sets the Auto Flag menu option. See Options Menu. Default: false.
-autobs/-xautobs or -autoObserve true/false — sets the Auto Observe menu option. See Options Menu. Default: false.
-autoKibitz — enables kibitzing of the engine's last thinking output (depth, score, time, speed, PV) before it moved, to the ICS, in zippy mode. The showThinking option must be switched on for this option to work. It also diverts similar kibitz information from an opponent engine that's playing you through the ICS over to the engine-output window, as if that engine was playing locally. 🧠
-seekGraph true/false or -sg — enables displaying of the seek graph by left-clicking the board when you're logged on to an ICS and currently idle. The seek graph shows all players currently seeking games on the ICS, plotted according to their rating and the time control of the game they seek, in three different colors (for rated, unrated and wild games). Computer ads show up as squares, human ads as dots. Default: false. 🔍
-autoRefresh true/false — enables automatic updating of the seek graph, by having the ICS send a running update of all newly placed and removed seek ads. This eats a substantial amount of communication bandwidth, and is only supported for FICS and ICC. Default: false. 🌈
-backgroundObserve true/false — when true, boards sent to you by the ICS from other games while you're playing (e.g. because you're observing them) will not be automatically displayed. Only a summary of time left and material of both players will appear in the message field above the board. XBoard will remember the last board it received this way, and will display it instead of the position in your own game when you press the right mouse button. No other information is stored on such games observed in the background; you cannot save such a game later, or step through its moves. This feature exists solely for the benefit of bughouse players, so they can peek at their partner's game without needing to logon twice. Default: false. 👀
-dualBoard true/false — in combination with -backgroundObserve true, this option displays the board of the background game side by side with your own game's board, so you can have it in view permanently. Any board or holdings info coming in will be displayed on the secondary board immediately. This feature is still experimental and largely unfinished. There's no animation or highlighting of moves on the secondary board. Default: false. 🛠️
-disguisePromotedPieces true/false — when set, promoted Pawns in crazyhouse/bughouse are displayed identical to primordial pieces of the same type, rather than distinguishable. Default: true.
-moves/-xmoves or -getMoveList true/false — sets the Get Move List menu option. See Options Menu. Default: true.
-alarm/-xalarm or -icsAlarm true/false — sets the ICS Alarm menu option. See Options Menu. Default: true.
-icsAlarmTime ms — sets the time in milliseconds for the ICS Alarm menu option. See Options Menu. Default: 5000.
lowTimeWarning true/false — controls a color change of the board as a warning that your time is running out. See Options Menu. Default: false.
-pre/-xpre or -premove true/false — sets the Premove menu option. See Options Menu. Default: true.
-prewhite/-xprewhite or -premoveWhite
-preblack/-xpreblack or -premoveBlack
-premoveWhiteText string
-premoveBlackText string

Set the menu options for specifying the first move for either color. See Options Menu. Defaults: false and empty strings, so no pre-moves.

-quiet/-xquiet or -quietPlay true/false — sets the Quiet Play menu option. See Options Menu. Default: false. 🤫
-colorizeMessages or -colorize/-xcolorize — setting colorizeMessages to true tells XBoard to colorize the messages it receives from the ICS. Colorization only works if your xterm supports ISO 6429 escape sequences for changing text colors. Default: true. 🌈
-colorShout foreground,background,bold
-colorSShout foreground,background,bold
-colorCShout foreground,background,bold
-colorChannel1 foreground,background,bold
-colorChannel foreground,background,bold
-colorKibitz foreground,background,bold
-colorTell foreground,background,bold
-colorChallege foreground,background,bold
-colorRequest foreground,background,bold
-colorSeek foreground,background,bold
-colorNormal foreground,background,bold

These options set the colors used when colorizing ICS messages. Every ICS message gets grouped into one of these categories: shout, sshout, channel 1, other channel, kibitz, tell, challenge, request (including abort, adjourn, draw, pause, and takeback), or normal (all other messages).

Each foreground or background argument can be one of the following: black, red, green, yellow, blue, magenta, cyan, white, or default. Here default means the default foreground or background color of your xterm. bold can be 1 or 0. If background is omitted, default is assumed; if bold is omitted, 0 is assumed. 💅

-soundProgram progname — set this to a sound-playing program that's installed and working on your system, and XBoard can play sound files when certain events occur, listed below. The default program name is "play". If any of the sound options is set to "$", the event rings the terminal bell by sending a ^G character to standard output, instead of playing a sound file. If an option is set to the empty string "", no sound is played for that event. 🔊
-soundDirectory directoryname — this option specifies where XBoard will look for sound files, when these aren't given as an absolute path name.
-soundShout filename
-soundSShout filename
-soundCShout filename
-soundChannel filename
-soundChannel1 filename
-soundKibitz filename
-soundTell filename
-soundChallenge filename
-soundRequest filename
-soundSeek filename

These sounds are triggered in the same way as the colorization events described above. They all default to "", no sound. They're played only if the colorizeMessages is on. CShout is synonymous with SShout. 🎀

-soundMove filename — this sound is played when a player other than yourself makes a move. Default: "$".
-soundRoar filename — this sound is played when a Lion makes a hit-and-run or double capture/ Default: "" (no sound). 🦁
-soundIcsAlarm filename — this sound is used by the ICS Alarm menu option. Default: "$".
-soundIcsWin filename — this sound is played when you win an ICS game. Default: "" (no sound). 🏆
-soundIcsLoss filename — this sound is played when you lose an ICS game. Default: "" (no sound). 😭
-soundIcsDraw filename — the lil bop that plays when you draw an ICS game 🎵🤝. Default: "" (aka silence, no sound).
-soundIcsUnfinished filename — the sound for when an ICS game you're actually in gets aborted, adjourned, or just... ends with no real conclusion 😭 (inconclusively, bestie). Default: "" (no sound).

🎀 Load and Save options 🎀

-lgf or -loadGameFile file
-lgi or -loadGameIndex index

okay so if loadGameFile is set, XBoard loads that game file right at startup. The file name - means the standard input, slay. If the file has more than one game in it, XBoard pops up a menu of the available games, with entries based on their PGN (Portable Game Notation) tags ✨. If loadGameIndex is set to N, the menu is suppressed and the Nth game found in the file is loaded immediately. The menu is also suppressed if matchMode is enabled or if the game file is a pipe — in those cases the first game in the file is loaded immediately. Use the pxboard shell script that ships with XBoard if you wanna pipe in files containing multiple games and still see the menu 🫶. If the loadGameIndex specifies an index -1, that triggers auto-increment of the index in matchMode, which means after every game the index gets incremented by one, so each game of the match is played from the next game in the file. Similarly, specifying an index value of -2 makes the index increment every two games, so each game in the file gets used twice (with reversed colors) 🔄. The rewindIndex option causes the index to be reset to the first game of the file when it has reached a specified value.

-rewindIndex n — makes a position file or game file get rewound back to its beginning after n positions or games in auto-increment matchMode. Peep loadPositionIndex and loadGameIndex 👀. Default: 0 (no rewind).
-td or -timeDelay seconds — the time delay between moves during Load Game or Analyze File. Fractional seconds are allowed, so try -td 0.4 ⏱️. A time delay value of -1 tells XBoard not to step through game files automatically. Default: 1 second.
-sgf or -saveGameFile file — if this is set, XBoard appends a record of every game played to the specified file 📝. The file name - means the standard output.
-autosave / -xautosave or -autoSaveGames true/false — sets the Auto Save menu option. See Options Menu. Default: false. Ignored if saveGameFile is set.
-onlyOwnGames true/false — suppresses auto-saving of ICS observed games 🙈. Default: false.
-lpf or -loadPositionFile file
-lpi or -loadPositionIndex index

if the loadPositionFile option is set, XBoard loads the specified position file at startup. The file name - means the standard input. If loadPositionIndex is set to N, the Nth position found in the file is loaded; otherwise the first position is loaded. If loadPositionIndex specifies an index -1, that triggers auto-increment of the index in matchMode, which means after every game the index gets incremented by one, so each game of the match is played from the next position in the file. Similarly, specifying an index value of -2 makes the index increment every two games, so each position in the file gets used twice (with the engines playing opposite colors) 🎨. The rewindIndex option causes the index to be reset to the first position of the file when it has reached a specified value.

-spf or -savePositionFile file — if this is set, XBoard appends the final position reached in every game played to the specified file 📌. The file name - means the standard output.
-positionDir directory — tells XBoard which directory file browsing should start in when you use the Load Position menu item 📂.
-pgnExtendedInfo true/false — when set, XBoard saves depth, score and time used for each move that the engine found as a comment in the PGN file 🧠. Default: false.
-pgnTimeLeft true/false — when set, XBoard saves the remaining clock time for the player who just moved as part of the pgnExtendedInfo, instead of the time that player thought about their latest move ⏳. Default: false.
-pgnEventHeader string — Default: false. Sets the name used in the PGN event tag to string. Default: "Computer Chess Game" 🏆.
-pgnNumberTag true/false — includes the (unique) sequence number of a tournament game in the saved PGN file as a 'number' tag 🔢. Default: false.
-saveOutOfBookInfo true/false — includes the info on how the engine(s) came out of their opening book in a special 'annotator' tag in the PGN file 📖. Default: true.
-oldsave / -xoldsave or -oldSaveStyle true/false — sets the Old Save Style menu option. See Options Menu. Default: false.
-gameListTags string — this character string lists the PGN tags that should be printed in the Game List, and their order 🏷️. The meaning of the codes is e=event, s=site, d=date, o=round, p=players, r=result, w=white Elo, b=black Elo, t=time control, v=variant, a=out-of-book info, c=result comment. Default: "eprd".
-ini or -settingsFile filename
-saveSettingsFile filename
@ filename

when XBoard encounters an option -settingsFile (or -ini for short), or @filename, it tries to read the mentioned file and substitutes its contents (presumably more command-line options) in place of the option 💅. In the case of -ini or -settingsFile, the name of a successfully read settings file is also remembered as the file to use for saving settings (automatically on exit, or on user command). An option of the form @filename does not affect saving. The option -saveSettingsFile does specify a name of the file to use for saving, without reading any options from it, and is therefore also effective when the file did not exist yet ✨. So the settings will be saved to the file specified in the last -saveSettingsFile or successful -settingsFile / -ini command, if any, and in /etc/xboard/xboard.conf otherwise. Usually the latter is only accessible for the system administrator though, and will be used to contain system-wide default settings, amongst which a -saveSettingsFile and -settingsFile options to specify a settings file accessible to the individual user, such as ~/.xboardrc in the user's home directory 🏠.

-saveSettingsOnExit true/false — controls saving of options in the settings file 💾. See Options Menu. Default: true.

🌈 User interface options 🌈

-noGUI — suppresses all GUI functions of XBoard (to speed up automated ultra-fast engine-engine games, which you don't wanna watch anyway 💀). There will be no board or clock updates, no printing of moves, and no update of the icon on the task bar in this mode. Straight-up headless vibes.
-logoSize N — this option controls the drawing of player logos next to the clocks 🖼️. The integer N specifies the width of the logo in pixels; the logo height will always be half the width. When N = 0, no logos will be displayed. Default: 0.
-firstLogo imagefile
-secondLogo imagefile

specify the images to be used as player logos when logoSize is non-zero, next to the white and black clocks respectively 🎀.

-autoLogo true/false
-logoDir filename

when autoLogo is set, XBoard will search for a PNG image file with the name of the engine or ICS in the directory specified by logoDir 🔍. For a human player it will look for a file <username>.png in this directory, but only when ~/.logo.png does not provide one.

-recentEngines number
-recentEngineList list

when the number is larger than zero, it determines how many recently used engines will be appended at the bottom of the Engines menu 📋. The engines will be saved in your settings file as the option recentEngineList, by their nicknames, and the most recently used one will always be sorted to the top 👑. If the list after that is longer than the specified number, the last one is discarded. Changes in the list will only become visible the next session, provided you saved the settings. Default: 6.

-oneClickMove true/false — when set, this option lets you enter moves by only clicking the to- or from-square, when only a single legal move to or from that square is possible 👆. Double-clicking a piece (or clicking an already selected piece) will instruct that piece to make the only capture it can legally do. Default: false.
-monoMouse true/false — when set, button 1 clicks on empty squares in Edit Position mode will be interpreted as button 3 clicks, so they place a piece 🖱️. Default: false.
-movesound / -xmovesound or -ringBellAfterMoves true/false — sets the Move Sound menu option. See Options Menu. Default: false. For compatibility with old XBoard versions, -bell / -xbell are also accepted as abbreviations for this option 🔔.
-analysisBell N — when N is non-zero, the Move Sound will be played whenever a new PV arrives in analysis mode after more than N seconds of analysis 🔕. Default: 0.
-exit / -xexit or -popupExitMessage true/false — sets the Popup Exit Message menu option. See Options Menu. Default: true.
-popup / -xpopup or -popupMoveErrors true/false — sets the Popup Move Errors menu option. See Options Menu. Default: false.
-queen / -xqueen or -alwaysPromoteToQueen true/false — sets the Always Queen menu option. See Options Menu. Default: false.
-sweepPromotions true/false — sets the Almost Always Promote to Queen menu option. See Options Menu. Default: false.
-legal / -xlegal or -testLegality true/false — sets the Test Legality menu option. See Options Menu. Default: true.
-size / -boardSize — okay so this one is literally the glow-up for your board 💅 It decides how big everything is by picking the pixel size of the pieces and setting a few related params. The sizeName can be one of: Titanic (129x129 pixel pieces), Colossal (116x116), Giant (108x108), Huge (95x95), Big (87x87), Large (80x80), Bulky (72x72), Medium (64x64), Moderate (58x58), Average (54x54), Middling (49x49), Mediocre (45x45), Small (40x40), Slim (37x37), Petite (33x33), Dinky (29x29), Teeny (25x25), or Tiny (21x21). Xboard installs with a set of scalable (svg) piece images, which it scales to any of the requested sizes. The square size can further be continuously scaled by sizing the board window, but this only adapts the size of the pieces, and has no effect on the width of the grid lines or the font choice (both of which would depend on the selected boardSize). The default depends on the size of your screen; it is approximately the largest size that will fit without clipping.

You can select other sizes or vary other layout parameters by providing a list of comma-separated values (with no spaces) as the argument. You do not need to provide all the values; for any you omit from the end of the list, defaults are taken from the nearest built-in size. The value n1 gives the piece size, n2 the width of the black border between squares, n3 the desired size for the clockFont, n4 the desired size for the coordFont, n5 the desired size for the messageFont, n6 the smallLayout flag (0 or 1), and n7 the tinyLayout flag (0 or 1). All dimensions are in pixels. If the border between squares is eliminated (0 width), the various highlight options will not work, as there is nowhere to draw the highlight. If smallLayout is 1 and titleInWindow is true, the window layout is rearranged to make more room for the title. If tinyLayout is 1, the labels on the menu bar are abbreviated to one character each and the buttons in the button bar are made narrower.

-overrideLineGap n — when n >= 0, this forces the width of the black border between squares to n pixels for any board size. Mostly used to suppress the grid entirely by setting n = 0, e.g. in xiangqi or just getting a prettier picture. When n < 0 the size-dependent width of the grid lines is used. Default: -1.
-coords / -xcoords / -showCoords true/false — sets the Show Coords menu option. See Options Menu. Default: false. The coordFont option specifies what font to use. 👀
-autoraise / -xautoraise / -autoRaiseBoard true/false — sets the Auto Raise Board menu option. See Options Menu. Default: true. ✨
-autoflip / -xautoflip / -autoFlipView true/false — sets the Auto Flip View menu option. See Options Menu. Default: true. 🔄
-flip / -xflip / -flipView true/false — if Auto Flip View is not set, or if you are observing but not participating in a game, then the positioning of the board at the start of each game depends on the flipView option. If flipView is false (the default), the board is positioned so that the white pawns move from the bottom to the top; if true, the black pawns move from the bottom to the top. In any case, the Flip menu option (see Options Menu) can be used to flip the board after the game starts. 🧚
-title / -xtitle / -titleInWindow true/false — if this option is true, XBoard displays player names (for ICS games) and game file names (for Load Game) inside its main window. If the option is false (the default), this information is displayed only in the window banner. You probably won't want to set this option unless the information is not showing up in the banner, as happens with a few X window managers. 💀
-buttons / -xbuttons / -showButtonBar True/False — if this option is False, xboard omits the [<<] [<] [P] [>] [>>] button bar from the window, allowing the message line to be wider. You can still get the functions of these buttons using the menus or their keyboard shortcuts. Default: true. 🎀
-evalZoom factor — the score interval (-1,1) is blown up on the vertical axis of the Evaluation Graph by the given factor. Default: 1. 📈
-evalThreshold n — score below n (centiPawn) are plotted as 0 in the Evaluation Graph. Default: 25. 🍓
-mono / -xmono / -monoMode true/false — determines whether XBoard displays its pieces and squares with two colors (true) or four (false). You shouldn't have to specify monoMode; XBoard will determine if it is necessary. 🌈
-showTargetSquares true/false — determines whether XBoard can highlight the squares a piece has legal moves to, when you grab that piece with the mouse. Default: false. 👑
-flashCount count / -flashRate rate / -flash / -xflash — these options enable flashing of pieces when they land on their destination square. flashCount tells XBoard how many times to flash a piece after it lands on its destination square. flashRate controls the rate of flashing (flashes/sec). Abbreviations: flash sets flashCount to 3. xflash sets flashCount to 0. Defaults: flashCount=0 (no flashing), flashRate=5. ✨
-highlight / -xhighlight / -highlightLastMove true/false — sets the Highlight Last Move menu option. See Options Menu. Default: false. 💖
-highlightMoveWithArrow true/false — sets the Highlight with Arrow menu option. See Options Menu. Default: false. 🏹
-blind / -xblind / -blindfold true/false — sets the Blindfold menu option. See Options Menu. Default: false. 🙈
-periodic / -xperiodic / -periodicUpdates true/false — controls updating of current move andnode counts in analysis mode. Default: true. 😭 (yes, “andnode” is exactly what it says, bestie)
-fSAN / -sSAN — causes the PV in thinking output of the mentioned engine to be converted to SAN before it is further processed.

⚠️ Warning: this might lose engine output not understood by the parser, and uses a lot of CPU power. Default: the PV is displayed exactly as the engine produced it.

-showEvalInMoveHistory true/false — controls whether the evaluation scores and search depth of engine moves are displayed with the move in the move-history window. Default: true. 🔥
-clockFont font — the font used for the clocks. If the option value is a pattern that does not specify the font size, XBoard tries to choose an appropriate font for the board size being used. Default Xaw: -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*. Default GTK: Sans Bold %d. ⏰
-coordFont font — the font used for rank and file coordinate labels if showCoords is true. If the option value is a pattern that does not specify the font size, XBoard tries to choose an appropriate font for the board size being used. Default Xaw: -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*. Default GTK: Sans Bold %d. 🔤
-messageFont font — the font used for popup dialogs, menus, etc. If the option value is a pattern that does not specify the font size, XBoard tries to choose an appropriate font for the board size being used. Default Xaw: -*-helvetica-medium-r-normal--*-*-*-*-*-*-*-*. Default GTK: Sans Bold %d. 💬
-tagsFont font — the font used in the Edit Tags dialog. If the option value contains %d, XBoard will replace it by an appropriate font for the board size being used. (Only used in GTK build.) Default: Sans Normal %d. 🏷️
-commentFont font — the font used in the Edit Comment dialog. If the option value contains %d, XBoard will replace it by an appropriate font for the board size being used. (Only used in GTK build.) Default: Sans Normal %d. ✍️
-icsFont font — the font used to display ICS output in the ICS Chat window. As ICS output often contains tables aligned by spaces, a mono-space font is recommended here. If the option value contains %d, XBoard will replace it by an appropriate font for the board size being used. (Only used in GTK build.) Default: Monospace Normal %d. 🗨️
-moveHistoryFont font — the font used in Move History and Engine Output windows. As these windows display mainly moves, one could use a figurine font here. If the option value contains %d, XBoard will replace it by an appropriate font for the board size being used. (Only used in GTK build.) Default: Sans Normal %d. 📜
-gameListFont font — the font used in the listbox of the Game List window. If the option value contains %d, XBoard will replace it by an appropriate font for the board size being used. (Only used in GTK build.) Default: Sans Bold %d. 📋
-fontSizeTolerance tol — in the font selection algorithm, a nonscalable font will be preferred over a scalable font if the nonscalable font's size differs by tol pixels or less from the desired size. A value of -1 will force a scalable font to always be used if available; a value of 0 will use a nonscalable font only if it is exactly the right size; a large value (say 1000) will force a nonscalable font to always be used if available. Default: 4. 📏
-pid / -pieceImageDirectory dir — this options control what piece images xboard uses. XBoard will look in the specified directory for an image in png or svg format for every piece type, with names like BlackQueen.svg, WhiteKnight.svg etc. When neither of these is found (or no valid directory is specified) XBoard will first ty to use an image White/BlackTile.svg in that same directory, and if that is not present either use the svg piece that was installed with it (from the source-tree directory svg). Both svg and png images will be scaled by XBoard to the required size, but the png pieces lose much in quality when scaled too much. Default: "". 🖼️
-inscriptions utf8string — the positions in the utf8string correspond to XBoard's piece types, and for each type a glyph can be defined. This glyph will then be rendered on top of the image for the piece. This is useful in combination with the White/BlackTile.svg images, which could be the image of a blank Shogi tile, for writing the kanji piece name on top of it on the fly. Default: "". 🈴
-whitePieceColor color
-blackPieceColor color
-lightSquareColor color
-darkSquareColor color
-highlightSquareColor color
-preoveHighlightColor color
-lowTimeWarningColor color

These are the colors for the pieces, the squares, and the square highlights. Yes, the manpage really does spell that one -preoveHighlightColor up there and -premoveHighlightColor down in the defaults — both spellings are in the original, bestie, I'm just the messenger 🫶 💅

Defaults, periodt:

    -whitePieceColor       #FFFFCC
    -blackPieceColor       #202020
    -lightSquareColor      #C8C365
    -darkSquareColor       #77A26D
    -highlightSquareColor  #FFFF00
    -premoveHighlightColor #FF0000
    -lowTimeWarningColor   #FF0000

And if you're living that grayscale monitor life, the original says you might prefer:

    -whitePieceColor       gray100
    -blackPieceColor       gray0
    -lightSquareColor      gray80
    -darkSquareColor       gray60
    -highlightSquareColor  gray100
    -premoveHighlightColor gray70
    -lowTimeWarningColor   gray70

Okay so important tea ☕: the PieceColor options only work properly if the image files defining the pieces were pure black & white (possibly anti-aliased to produce gray scales and semi-transparancy), like the piece images that come with the install. Their effect on colored pieces is undefined. And the SquareColor option only has an effect when no board textures are used. Noted and filed 💀

-trueColors true/false — when you set this, it suppresses the effect of the PieceColor options mentioned above. Recommended for images that are already colored ✨
-useBoardTexture true/false
-liteBackTextureFile filename
-darkBackTextureFile filename

These say which .png image files get used to draw the board squares, and whether they should be used rather than just using simple colors. The algorithm for cutting squares out of a given bitmap is such that the picture is perfectly reproduced when a bitmap the size of the complete board is given. If the filename ends in -NxM.png, with integer N and M, it's assumed to contain a bitmap of a complete board of N files and M ranks, and XBoard will scale it to exactly match the current square size. If N=M=0 it scales the entire bitmap to the size of the board, irrespective of the number of files and ranks of the latter. Without any -NxM suffix, textures are only blown up by an integer factor when they're smaller than the square size, or, when the name starts with xq, too small to cover the complete Xiangqi board. Default: false and "".

-drag / -xdrag or -animateDragging true/false — sets the Animate Dragging menu option. See Options Menu. Default: true.
-animate / -xanimate or -animateMoving true/false — sets the Animate Moving menu option. See Options Menu. Default: true.
-animateSpeed n — number of milliseconds delay between each animation frame when Animate Moves is on.
-autoDisplayComment true/false
-autoDisplayTags true/false

If set to true, these options cause the window with the move comments, and the window with PGN tags, respectively, to pop up automatically when such tags or comments are encountered during the replaying of a stored or loaded game. Default: true.

-pasteSelection true/false — if this is true, the Paste Position and Paste Game options paste from the currently selected text. If false, they paste from the clipboard. Default: false.
-autoCopyPV true|false — when this is set, the position displayed on the board when you terminate a PV walk (initiated by a right-click on board or engine-output window) gets automatically put on the clipboard as FEN. Default: false.
-dropMenu true|false — lets you emulate old behavior, where the right mouse button brings up the (now deprecated) drop menu rather than displaying the position at the end of the principal variation. Default: False.
-pieceMenu true|false — lets you emulate old behavior, where the right mouse button brings up the (now deprecated) piece menu in Edit Position mode. From this menu you can select the piece to put on the square you clicked to bring up the menu, or select items such as clear board. You can also promote or demote a clicked piece to convert it into an unorthodox piece that is not directly in the menu, or give the move to black or white.
-variations true|false — when this is on, you can start new variations in Edit Game or Analyze mode by holding the Shift key down while entering a move. When it's off, the Shift key will be ignored. Default: False.
-appendPV true|false — when this is on, a button 3 click left of a PV in the Engine Output window will play the first move of that PV in Analyze mode, or as many moves as you walk through it by moving the mouse. Default: False.
-absoluteAnalysisScores true|false — when true, scores on the Engine Output window during analysis will be printed from the white point-of-view, rather than the side-to-move point-of-view. Default: False.
-scoreWhite true|false — when true, scores will always be printed from the white point-of-view, rather than the side-to-move point-of-view. Default: False.
-memoHeaders true|false — when true, column headers will be displayed in the Engine Output window for the depth, score, time and nodes data. A button 3 click on these headers will hide or show the corresponding data. (Not intended for dynamic use, as already printed data of the current search will not be affected!) Defaul: False.

Not me reading "Defaul" and leaving it exactly as-is because that's literally what the manpage says 😭 keeping the source honest, fr fr.

👑 Adjudication Options 👑

-adjudicateLossThreshold n — if the given value is non-zero, XBoard adjudicates the game as a loss if both engines agree for a duration of 6 consecutive ply that the score is below the given score threshold for that engine. Make sure the score is interpreted properly by XBoard, using -firstScoreAbs and -secondScoreAbs if needed. Default: 0 (no adjudication).
-adjudicateDrawMoves n — if the given value is non-zero, XBoard adjudicates the game as a draw if after the given number of moves it was not yet decided. Default: 0 (no adjudication).
-checkMates true/false — if this is set, XBoard detects all checkmates and stalemates, and ends the game as soon as they occur. Legality-testing must be switched on for this option to work. Default: true.
-testClaims true/false — if this is set, XBoard verifies all result claims made by engines, and those who send false claims will forfeit the game because of it. Legality-testing must be switched on for this option to work. Default: true.
-materialDraws true/false — if this is set, XBoard adjudicates games as draws when there's no sufficient material left to inflict a checkmate. This applies to KBKB with like bishops (any number, actually), and to KBK, KNK and KK. Legality-testing must be switched on for this option to work. Default: true.
-trivialDraws true/false — if this is set, XBoard adjudicates games as draws that cannot be usually won without opponent cooperation. This applies to KBKB with unlike bishops, and to KBKN, KNKN, KNNK, KRKR and KQKQ. The draw is called after 6 ply into these end-games, to allow quick mates that can occur in some exceptional positions to be found by the engines. KQKQ does not really belong in this category, and might be taken out in the future. (When bitbase-based adjudications are implemented.) Legality-testing must be on for this option to work. Default: false.
-ruleMoves n — if the given value is non-zero, XBoard adjudicates the game as a draw after the given number of consecutive reversible moves. Engine draw claims are always accepted after 50 moves, irrespective of the given value of n.
-repeatsToDraw n — if the given value is non-zero, xboard adjudicates the game as a draw if a position is repeated the given number of times. Engines draw claims are always accepted after 3 repeats, (on the 3rd occurrence, actually), irrespective of the value of n. Beware that positions that have different castling or en-passant rights do not count as repeats, XBoard is fully e.p. and castling aware! 🧚

🌸 Install options 🌸

--show-config parameter — when called with this option, XBoard will close immediately after printing the value of the indicated configuration parameter, or, when no parameter was given, after printing a list of all such parameters. Currently the only valid values for parameter are Datadir and Sysconfdir. This option can be used by install scripts for board themes to figure out where the currently active XBoard stores its data.
-date timestamp
-saveDate timestamp

These options specify an epoch as an integer number. The saveDate option is written by XBoard in the settings file every time the settings are saved, with the current time, so that later runs of XBoard can know this. The date option can be included in settings files to indicate when lines following it were added to those files. Some options will be ignored if the epoch specified by the latest date option predates the -saveDate setting (implying they must have been seen before).

-autoInstall list — when the list is set to a non-empty string, XBoard will scan the operating system's plugin directory for engines supporting UCI and XBoard protocol at startup. When it finds an engine that was installed after it last saved its settings, a line to launch that engine (as per specs in the plugin file) is appended to the -firstChessProgramNames list of installed engines. In the future it will be possible to use the autoInstall list to limit this automatic adding of engines based on the chess variant they play. future features, we love to see it 💜
-addMasterOption string — drops the string you give it as an extra line in XBoard's master settings file, but only after it first adds a line with a date option to timestamp the whole thing. The whole point is to sneak options of the install type (iykyk, more below) into the master file, so that any XBoard that hasn't peeped them since it last saved its own settings will then process them. 💅
-autoClose — the mere presence of this option makes XBoard dip out immediately after it's done processing all its options (from the settings file and the command line, bestie). Usually you'd call it from install scripts alongside options that change XBoard's settings files, so XBoard can run in batch mode instead of being interactive. ✨
-installEngine string — appends the given string as an extra line to the value of the firstChessProgramNames option, but only when the -saveDate setting comes before the -date setting. The idea is to add it to the master settings file with the help of -addMasterOption in an engine's install script, as a way to broadcast that a new engine exists to all users, who'd then see it automatically registered with XBoard. 🫶 Lowkey made obsolete by the plugin standard (check the autoInstall option) which broadcasts that same presence in a non-XBoard-specific way by dropping *.eng files in some system directory. Not me living in the past…
-installTheme string — adds the given string as an extra line to the value of the -themeNames option when the -saveDate setting comes before the -date setting. Meant to be added to the master settings file with the aid of -addMasterOption in the install script of board graphics themes, so you can broadcast that a new theme is available to all users — who'd then see the theme pop up automatically in the listbox in the View Board menu dialog the next time they run XBoard. 🎀

🌈 Other options 🌈

-ncp / -xncp or -noChessProgram true/false — if this one's true, XBoard just vibes as a passive chessboard; it won't start a chess engine at all. Flipping this on also turns off clockMode. Default: false. 🧊
-viewer
-viewerOptions string — if the volatile option viewer shows up on the command line, then the value of the persistent option viewerOptions (as stored in the settings file) gets appended to the command line. The view option gets used by desktop associations with game or position file types, so that viewerOptions can configure the exact mode XBoard starts in when it's acting on such a file (e.g. in -ncp mode, or analyzing with your favorite engine 💖). These options also get appended automatically when Board is invoked with a single argument that isn't an option name — that argument is then assumed to be the name of a loadGameFile, or (when the name ends in .fen) a loadPositionFile. Default: "-ncp -engineOutputUp false -saveSettingsOnExit false".
-tourneyOptions string — when XBoard is invoked with a single argument that's a file with a .trn extension, it'll assume that argument is the value of a tourneyFile option, and then append the value of the persistent option tourneyOptions (as stored in the settings file) to the command line. So the value of tourneyOptions can configure XBoard to automatically start running a tournament when it should act on that file. Default: "-ncp -mm -saveSettingsOnExit false". 🏆
-mode or -initialMode modename — if you give this, XBoard picks the given modename from the Mode menu after starting and (if applicable) after processing the loadGameFile or loadPositionFile option. Default: "" (no selection). The other supported values are MachineWhite, MachineBlack, TwoMachines, Analysis, AnalyzeFile, EditGame, EditPosition, and Training.
-variant varname — activates (sometimes partial) support for playing chess variants against a local engine, or for editing variant games. You don't need this flag in ICS mode. The recognized variant names are:

normal        Normal chess
wildcastle    Shuffle chess, king can castle from d file
nocastle      Shuffle chess, no castling allowed
fischerandom  Fischer Random shuffle chess
bughouse      Bughouse, ICC/FICS rules
crazyhouse    Crazyhouse, ICC/FICS rules
losers        Lose all pieces or get mated (ICC wild 17)
suicide       Lose all pieces including king (FICS)
giveaway      Try to have no legal moves (ICC wild 26)
twokings      Weird ICC wild 9
kriegspiel    Opponent's pieces are invisible
atomic        Capturing piece explodes (ICC wild 27)
3check        Win by giving check 3 times (ICC wild 25)
shatranj      An ancient precursor of chess (ICC wild 28)
xiangqi       Chinese Chess (on a 9x10 board)
shogi         Japanese Chess (on a 9x9 board & piece drops)
capablanca    Capablanca Chess (10x8 board, with Archbishop
              and Chancellor pieces)
gothic        similar, with a better initial position
caparandom    An FRC-like version of Capablanca Chess (10x8)
janus         A game with two Archbishops (10x8 board)
courier       Medieval intermediate between shatranj and
              modern Chess (on 12x8 board)
falcon        Patented 10x8 variant with two Falcon pieces
berolina      Pawns capture straight ahead, and move diagonally
cylinder      Pieces wrap around the board edge
knightmate    King moves as Knight, and vice versa
super         Superchess (shuffle variant with 4 exo-pieces)
makruk        Thai Chess (shatranj-like, P promotes on 6th rank)
asean         ASEAN Chess (a modernized version of Makruk)
spartan       Spartan Chess (black has unorthodox pieces)
great         Great Shatranj, a 10x8 variant without sliders
grand         Grand Chess, on 10x10 with Capablanca pieces
lion          Mighty-Lion Chess, with a multi-capturing Lion
elven         Eleven Chess, with Lion and crowned sliders on 10x10
chu           Chu Shogi, historic 12x12 variant with 2x46 pieces
fairy         A catchall variant in which all piece types
              known to XBoard can participate (8x8)
unknown       Catchall for other unknown variants

In the shuffle variants, XBoard does shuffle the pieces for you, though you can still do it by hand using Edit Position. Some variants are only supported in ICS mode, including bughouse and kriegspiel. Berolina and cylinder chess are only partially supported, and can only be played with legality testing off. 😭

Beyond these standard variants, engines can define variants with totally arbitrary names, briefing XBoard transparently on the rules for piece movement, board size and initial setup, so they work nearly as well as the fully-supported standard variants. (But obvi only while using that engine.) Heads up though: you might have to change the adjudication settings for some variants. E.g. it makes zero sense to adjudicate a draw after 50 reversible moves in variants that have a 64-move rule, or no similar rule at all. 💀

Default: "normal". Except when the first engine gave an explicit list of variants it supports, and 'normal' isn't amongst those — in that case, the first variant the engine mentioned it did play gets chosen.

-boardHeight N — lets you set a non-standard number of board ranks in any variant. If the height is given as -1, the default height for the variant is used. Default: -1.
-boardWidth N — lets you set a non-standard number of board files in any variant. If the width is given as -1, the default width for the variant is used. With a non-standard width, the initial position will always be an empty board, since the usual opening array won't fit. Default: -1. 🦋
-holdingsSize N — lets you set a non-standard size for the holdings in any variant. If the size is given as -1, the default holdings size for the variant is used. The first N piece types will go into the holdings on capture, and you'll be able to drop them on the board instead of making a normal move. If the size equals 0, there will be no holdings. Default: -1.
-defaultFrcPosition N — specifies the number of the opening position in shuffle games like Chess960. A value of -1 means the position is randomly generated by XBoard at the beginning of every game. Default: -1. ⭐
-pieceToCharTable string — okay so these are the characters XBoard uses to represent the piece types it knows about, in FEN diagrams and in SAN moves. Real talk, you should basically never have to touch this one, because every variant already ships with its own default piece representation for FEN and that's plenty for normal human behaviour. 💅 But if you do use it: your string argument has to name an even number of pieces, otherwise it just gets straight-up ignored, because white and black pieces have to be listed separately, in that order. The last letter for each color is the King. The letters before that are PNBRQ, and then a whole glittery parade of fairy pieces in an order that, and I quote, has not fully crystallized yet — currently FEACWMOHIJGDVLSU, where F=Ferz, Elephant, A=Archbishop, C=Chancellor, W=Wazir, M=Commoner, O=Cannon, H=Nightrider. You should list at least all the pieces that actually show up in the variant you're playing, bestie. If your string has fewer characters than XBoard has pieces, the un-mentioned pieces get assigned a period . and become unusable in that variant. You can also deliberately hand a piece a period, and in that case it won't be counted when deciding which captured pieces can go into the holdings. A tilde ~ as a piece name means this piece is what represents a promoted Pawn in crazyhouse-like games, i.e. on capture it turns back into a Pawn. A + similarly means the piece is a shogi-style promoted piece that reverts to its non-promoted version on capture (not to a Pawn, okay, different thing entirely). By default the second 11 pieces XBoard knows are the promoted forms of the first 11. A piece specified by the character combination ^ plus letter is assumed to be the promoted form of the piece indicated by that letter, and gets a + assigned. And because the alphabet is so limiting, piece IDs can also be 'dressed letters' — a single letter (upper case for white, lower case for black) followed by a single quote or an exclamation point. Default: "" (meaning the default for the variant is used).
-pieceNickNames string — the characters in this string get interpreted the exact same way as in the pieceToCharTable option. The twist: on input, piece-ID letters are looked up in the nicknames first, and only if they're not defined there do they fall back to the normal pieceToCharTable. Which means you can have two different letters designate the same piece — like N as an alternative to H for Horse in Xiangqi — so reading non-compliant notations is way easier. Default: ""
-colorNickNames string — the side-to-move field in a FEN gets matched against the letters in this string first (first character for white, second for black), before it's ever matched to the regular w and b. So if some cursed FEN out there uses r for white, you're covered. Default: ""
-debug / -xdebug or -debugMode true/false — turns on debugging printout. ✨
-debugFile filename or -nameOfDebugFile filename — sets the name of the file where XBoard saves debug information, including all communication to and from the engines. A %d in the given file name (e.g. game%d.debug) gets replaced by the unique sequence number of a tournament game, so the debug output of each game lands in its own separate file. Very organized of her. 🎀
-engineDebugOutput number — specifies how XBoard should handle unsolicited output from the engine, with respect to saving it in the debug file. The output is further (hopefully) ignored. If number=0, XBoard refrains from writing such spurious output to the debug file. If number=1, all engine output is written faithfully to the debug file. If number=2, any protocol-violating line is prefixed with a # character — as the engine itself should have done if it wanted to submit info for inclusion in the debug file. This option exists for the benefit of applications that use the debug file as a source of information, like the broadcaster of live games TLCV / TLCS. Such applications can be protected from spurious engine output that might otherwise confuse them. 🫶
-rsh or -remoteShell shell-name — name of the command used to run programs remotely. The default is rsh or remsh, determined when XBoard is configured and compiled.
-ruser or -remoteUser user-name — user name on the remote system when running programs with the remoteShell. The default is your local user name.
-userName username — the name under which the Human player will be listed in the PGN file. Default is the login name on your local computer.
-delayBeforeQuit number
-delayAfterQuit number — these options order pauses before and after sending the "quit" command to an engine that must be terminated. The pause between quit and the previous command is specified in milliseconds. The pause after quit is used to schedule a kill signal to be sent to the engine process after the number of specified seconds plus one. Heads up: this signal is a different one than the termination signal described in the protocol specs — the one engines can suppress or ignore, which is sent directly after the "quit" command. Setting delayAfterQuit to -1 will suppress sending of the kill signal. Default: 0
-searchMode n — the integer n encodes the mode for the find position function. Default: 1 (= Exact position match)
-eloThresholdBoth elo
-eloThresholdAny elo — defines a lower limit for the Elo rating, which has to be surpassed before a game will even be considered when searching for a board position. Default: 0
-dateThreshold year — only games not played before the given year will be considered when searching for a board position.

🦋 CHESS SERVERS 🦋

An "Internet Chess Server", or "ICS", is a place on the Internet where people get together to play chess, watch other people's games, or just vibe and chat. You can connect with either telnet or a client program like XBoard. There are thousands of registered users on the different ICS hosts, and it is not unusual to meet 200 on both chessclub.com and freechess.org. So many besties. 👑

Most people can just type xboard -ics to start XBoard as an ICS client. Invoking XBoard this way connects you to the Internet Chess Club (ICC), a commercial ICS — and you can log in there as a guest even if you don't have a paid account. 💖 To connect to the largest Free ICS (FICS), use the command xboard -ics -icshost freechess.org instead, or swap in a different host name to connect to your favorite ICS. For a full description of the command-line options that control the ICS connection and change the default values of ICS options, see ICS options.

While you're running XBoard as an ICS client, you use the terminal window you started XBoard from as the place to type in commands and read information that isn't available on the chessboard. Lowkey essential.

The first time you need the terminal is to enter your login name and password, if you're a registered player. (You don't have to do this manually though — the icsLogon option can do it for you. See ICS options.) If you are not registered, just enter g as your name, and the server will pick a unique guest name for you. Slay. ✨

Some useful ICS commands include:

help <topic> — to get help on the given <topic>. To get a list of possible topics, type help with no topic. Try the help command before you ask other people on the server for help, bestie, fr fr. For example, help register tells you how to become a registered ICS player.
who <flags> — to see a list of people who are logged on. Administrators (the people you should talk to if you have a problem) are marked with the character *, an asterisk. The <flags> let you display only selected players: for example, who of shows a list of players who are interested in playing but do not have an opponent.
games — to see what games are being played.
match <player> [<mins>] [<inc>] — to challenge another player to a game. Both opponents get <mins> minutes for the game, and <inc> seconds will be added after each move. If another player challenges you, the server asks if you want to accept the challenge; use the accept or decline commands to answer.
accept
decline — to accept or decline another player's offer. The offer may be to start a new game, or to agree to a draw, adjourn or abort the current game. See Action Menu. If you have more than one pending offer (for example, if more than one player is challenging you, or if your opponent offers both a draw and to adjourn the game), you have to supply additional information, by typing something like accept <player>, accept draw, or draw.
draw
adjourn
abort — asks your opponent to terminate a game by mutual agreement. Adjourned games can be continued later. Your opponent can either decline your offer or accept it (by typing the same command or typing accept). In some cases these commands work immediately, without asking your opponent to agree. For example, you can abort the game unilaterally if your opponent is out of time, and you can claim a draw by repetition or the 50-move rule if available simply by typing draw. 💀 iconic.
finger <player> — to get information about the given <player>. (Default: yourself.)
vars — to get a list of personal settings.
set <var> <value> — to modify these settings.
observe <player> — to observe an ongoing game of the given <player>.
examine
oldmoves — to review a recently completed game.

Some special XBoard features are activated when you are in examine mode on ICS. See the descriptions of the menu commands Forward, Backward, Pause, ICS Client, and Stop Examining on the Edit Menu, Mode Menu, and Action Menu. 🌸

🔥 FIREWALLS 🔥

okay bestie so here's the tea ☕ — by default, XBoard talks to an Internet Chess Server by opening a TCP socket directly from the machine it's running on to the ICS. But if there's a firewall sitting between your machine and the ICS?? that's just not gonna happen, bestie. so here are some recipes for getting around the common kinds of firewalls using special options to XBoard. ✨

IMPORTANT: see the paragraph in the below about extra echoes, in Limitations. 👀

🧚 Recipe #1: telnet to the firewall, then telnet from there

Say you can't telnet directly to ICS, but you can telnet to a firewall host, log in, and then telnet from there to ICS. let's say the firewall is called firewall.example.com. set command-line options like this:

xboard -ics -icshost firewall.example.com -icsport 23

then when you run XBoard in ICS mode, you'll be prompted to log in to the firewall host. this works because port 23 is the standard telnet login service. do that, then telnet to ICS, using a command like telnet chessclub.com 5000, or whatever command the firewall provides for telnetting to port 5000. 💅

🧚 Recipe #2: port 23 because your firewall is picky

if your firewall lets you telnet (or rlogin) to remote hosts but doesn't let you telnet to port 5000, you may be able to connect to the chess server on port 23 instead — that's the port the telnet program uses by default. some chess servers support this (including chessclub.com and freechess.org), while some do not. 🥲

🧚 Recipe #3: hop through a host outside the firewall

if your chess server does not allow connections on port 23 and your firewall does not allow you to connect to other ports, you may be able to connect by hopping through another host outside the firewall that you have an account on. for instance, suppose you have a shell account at foo.edu. follow the recipe above, but instead of typing telnet chessclub.com 5000 to the firewall, type telnet foo.edu (or rlogin foo.edu), log in there, and then type telnet chessclub.com 5000. 🦋

🧚 Recipe #4: rsh gateway

suppose you can't telnet directly to ICS, but you can use rsh to run programs on a firewall host, and that host can telnet to ICS. let's say the firewall is called rsh.example.com. set command-line options like this:

xboard -ics -gateway rsh.example.com -icshost chessclub.com

then when you run XBoard in ICS mode, it will connect to the ICS by using rsh to run the command telnet chessclub.com 5000 on host rsh.example.com. iconic. 👑

🧚 Recipe #5: the special `ptelnet` program

suppose you can telnet anywhere you want, but you have to run a special program called ptelnet to do so. 👀

first, we'll consider the easy case, in which ptelnet chessclub.com 5000 gets you to the chess server. in this case set command line options like this:

xboard -ics -telnet -telnetProgram ptelnet

then when you run XBoard in ICS mode, it will issue the command ptelnet chessclub.com 5000 to connect to the ICS. slay. ✨

next, suppose that ptelnet chessclub.com 5000 doesn't work — that is, your ptelnet program doesn't let you connect to alternative ports. as noted above, your chess server may allow you to connect on port 23 instead. in that case, just add the option -icsport "" to the above command. but if your chess server doesn't let you connect on port 23, you will have to find some other host outside the firewall and hop through it. for instance, suppose you have a shell account at foo.edu. set command line options like this:

xboard -ics -telnet -telnetProgram ptelnet -icshost foo.edu -icsport ""

then when you run XBoard in ICS mode, it will issue the command ptelnet foo.edu to connect to your account at foo.edu. log in there, then type telnet chessclub.com 5000. 💖

🧚 timestamp and timeseal, and firewalls

ICC timestamp and FICS timeseal do not work through some firewalls. you can use them only if your firewall gives a clean TCP connection with a full 8-bit wide path. if your firewall allows you to get out only by running a special telnet program, you can't use timestamp or timeseal across it. 😭 but if you have access to a computer just outside your firewall, and you have much lower netlag when talking to that computer than to the ICS, it might be worthwhile running timestamp there. follow the instructions above for hopping through a host outside the firewall (foo.edu in the example), but run timestamp or timeseal on that host instead of telnet. 🧚

🧚 SOCKS firewalls

suppose you have a SOCKS firewall that will give you a clean 8-bit wide TCP connection to the chess server, but only after you authenticate yourself via the SOCKS protocol. in that case, you could make a socksified version of XBoard and run that. if you are using timestamp or timeseal, you will to socksify it, not XBoard — this may be difficult seeing that ICC and FICS do not provide source code for these programs. 😬 socksification is beyond the scope of this document, but see the SOCKS Web site at http://www.socks.permeo.com/. if you are missing SOCKS, try http://www.funbureau.com/. 🌈

🌸 ENVIRONMENT VARIABLES 🌸

game and position files are found in a directory named by the CHESSDIR environment variable. if this variable is not set, the current working directory is used. if CHESSDIR is set, XBoard actually changes its working directory to $CHESSDIR, so any files written by the chess engine will be placed there too. 🫶

💀 LIMITATIONS AND KNOWN BUGS 💀

okay bestie, the messy part. no cap, here's everything that's lowkey cursed:

there is no way for two people running copies of XBoard to play each other without going through an Internet Chess Server. 🙈
under some circumstances, your ICS password may be echoed when you log on. 💀
if you are connecting to the ICS by running telnet on an Internet provider or firewall host, you may find that each line you type is echoed back an extra time after you hit <Enter>. if your Internet provider is a Unix system, you can probably turn its echo off by typing stty -echo after you log in, and/or typing <^E><Enter> (Ctrl+E followed by the Enter key) to the telnet program after you have logged into ICS. it is a good idea to do this if you can, because the extra echo can occasionally confuse XBoard's parsing routines. 👀
the game parser recognizes only algebraic notation. periodt.
many of the following points used to be limitations in XBoard 4.2.7 and earlier, but are now fixed:
- the internal move legality tester in XBoard 4.3.xx does look at the game history, and is fully aware of castling or en-passant-capture rights. it permits castling with the king on the d file because this is possible in some "wild 1" games on ICS. ✨
- the piece-drop menu does not check piece drops in bughouse to see if you actually hold the piece you are trying to drop. but this way of dropping pieces should be considered an obsolete feature, now that pieces can be dropped by dragging them from the holdings to the board. anyway, if you would attempt an illegal move when using a chess engine or the ICS, XBoard will accept the error message that comes back, undo the move, and let you try another. 🫶
- FEN positions saved by XBoard do include correct information about whether castling or en passant are legal, and also handle the 50-move counter.
- the mate detector does not understand that non-contact mate is not really mate in bughouse. the only problem this causes while playing is minor: a "#" (mate indicator) character will show up after a non-contact mating move in the move list. XBoard will not assume the game is over at that point, not even when the option Detect Mates is on.
- Edit Game mode always uses the rules of the selected variant, which can be a variant that uses piece drops. you can load and edit games that contain piece drops. the (obsolete) piece menus are not active, but you can perform piece drops by dragging pieces from the holdings.
- Fischer Random castling is fully understood. you can enter castlings by dragging the King on top of your Rook. you can probably also play Fischer Random successfully on ICS by typing castling moves into the ICS Interaction window. 👑
the menus may not work if your keyboard is in Caps Lock or Num Lock mode. this seems to be a problem with the Athena menu widget, not an XBoard bug. (not me blaming the widget 💅)
also see the ToDo file included with the distribution for many other possible bugs, limitations, and ideas for improvement that have been suggested. 🦋

🎀 REPORTING PROBLEMS 🎀

you can report bugs and problems with XBoard using the bug tracker at https://savannah.gnu.org/projects/xboard/ or by sending mail to <bug-xboard@gnu.org>. it can also be useful to report or discuss bugs in the WinBoard Forum at http://www.open-aurec.com/wbforum/, WinBoard development section. 🫶

please use the script program to start a typescript, run XBoard with the -debug option, and include the typescript output in your message. also tell us what kind of machine and what operating system version you are using. the command uname -a will often tell you this. ✨

if you improve XBoard, please send a message about your changes, and we will get in touch with you about merging them in to the main line of development. 🌈

💖 AUTHORS AND CONTRIBUTORS 💖

Okay so bestie, before we get into cmail, we gotta give credit where credit is due, because this whole thing was a group project that ate. 💅

Chris Sears and Dan Sears wrote the original XBoard. They were responsible for versions 1.0 through 1.2. The color scheme was taken from Wayne Christopher's XChess program. 🎨

Tim Mann was primarily responsible for XBoard versions 1.3 through 4.2.7, and for WinBoard (a port of XBoard to Microsoft Win32) from its inception through version 4.2.7.

John Chanak contributed the initial implementation of ICS mode. Evan Welsh wrote CMail, and Patrick Surry helped in designing, testing, and documenting it. Elmar Bartel contributed the new piece bitmaps introduced in version 3.2. Jochen Wiedmann converted the documentation to texinfo. Frank McIngvale added click/click moving, the Analysis modes, piece flashing, ZIICS import, and ICS text colorization to XBoard. Hugh Fisher added animated piece movement to XBoard, and Henrik Gram added it to WinBoard. Mark Williams contributed the initial (WinBoard-only) implementation of many new features added to both XBoard and WinBoard in version 4.1.0, including copy/paste, premove, icsAlarm, autoFlipView, training mode, auto raise, and blindfold. Ben Nye contributed X copy/paste code for XBoard.

In a fork from version 4.2.7, Alessandro Scotti added many elements to the user interface of WinBoard, including the board textures and font-based rendering, the evaluation-graph, move-history and engine-output window. He was also responsible for adding the UCI support. ✨

H. G. Muller continued this fork of the project, producing version 4.3. He made WinBoard castling- and e.p.-aware, added variant support with adjustable board sizes, the crazyhouse holdings, and the fairy pieces. In addition he added most of the adjudication options, made WinBoard more robust in dealing with buggy and crashing engines, and extended time control with a time-odds and node-count-based modes. Most of the options that initially were WinBoard only have now been back-ported to XBoard.

Michel van den Bergh provided the code for reading Polyglot opening books. 📚

Meanwhile, some work continued on the GNU XBoard project maintained at savannah.gnu.org, but version 4.2.8 was never released. Daniel Mehrmann was responsible for much of this work.

Most recently, Arun Persaud worked with H. G. Muller to merge all the features of the never-released XBoard/WinBoard 4.2.8 of the GNU XBoard project and the never-released 4.3.16 from H. G.'s fork into a unified XBoard/WinBoard 4.4, which is now available both from the savannah.gnu.org web site and the WinBoard forum. 👑

🎀 CMAIL 🎀

The cmail program can help you play chess by email with opponents of your choice using XBoard as an interface. It's giving snail mail but make it chess, and honestly? Iconic. 🦋

You will usually run cmail without giving any options.

CMail options

-h — Displays cmail usage information.
-c — Shows the conditions of the GNU General Public License. See Copying.
-w — Shows the warranty notice of the GNU General Public License. See Copying.
-v, -xv — Provides or inhibits verbose output from cmail and XBoard, useful for debugging. The -xv form also inhibits the cmail introduction message.
-mail, -xmail — Invokes or inhibits the sending of a mail message containing the move.
-xboard, -xxboard — Invokes or inhibits the running of XBoard on the game file.
-reuse, -xreuse — Invokes or inhibits the reuse of an existing XBoard to display the current game.
-remail — Resends the last mail message for that game. This inhibits running XBoard.
-game <name> — The name of the game to be processed.
-wgames <number>, -bgames <number>, -games <number> — Number of games to start as White, as Black or in total. Default is 1 as white and none as black. If only one color is specified then none of the other color is assumed. If no color is specified then equal numbers of White and Black games are started, with the extra game being as White if an odd number of total games is specified.
-me <short name>, -opp <short name> — A one-word alias for yourself or your opponent.
-wname <full name>, -bname <full name>, -myname <full name>, -oppname <full name> — The full name of White, Black, yourself or your opponent.
-wna <net address>, -bna <net address>, -na <net address>, -oppna <net address> — The email address of White, Black, yourself or your opponent.
-dir <directory> — The directory in which cmail keeps its files. This defaults to the environment variable $CMAIL_DIR or failing that, $CHESSDIR, $HOME/Chess or ~/Chess. It will be created if it does not exist.
-arcdir <directory> — The directory in which cmail archives completed games. Defaults to the environment variable $CMAIL_ARCDIR or, in its absence, the same directory as cmail keeps its working files (above).
-mailprog <mail program> — The program used by cmail to send email messages. This defaults to the environment variable $CMAIL_MAILPROG or failing that /usr/ucb/Mail, /usr/ucb/mail or Mail. You will need to set this variable if none of the above paths fit your system. 🫶
-logFile <file> — A file in which to dump verbose debugging messages that are invoked with the -v option.
-event <event> — The PGN Event tag (default Email correspondence game).
-site <site> — The PGN Site tag (default NET).
-round <round> — The PGN Round tag (default -, not applicable).
-mode <mode> — The PGN Mode tag (default EM, Electronic Mail).

Other options

Any option flags not listed above are passed through to XBoard. Invoking XBoard through CMail changes the default values of two XBoard options: The default value for -noChessProgram is changed to true; that is, by default no chess engine is started. The default value for -timeDelay is changed to 0; that is, by default XBoard immediately goes to the end of the game as played so far, rather than stepping through the moves one by one. You can still set these options to whatever values you prefer by supplying them on CMail's command line. See Options.

Starting a CMail Game

Type cmail from a shell to start a game as white. After an opening message, you will be prompted for a game name, which is optional -- if you simply press <Enter>, the game name will take the form you-VS-opponent. You will next be prompted for the short name of your opponent. If you haven't played this person before, you will also be prompted for his/her email address. cmail will then invoke XBoard in the background. Make your first move and select Mail Move from the File menu. See File Menu. If all is well, cmail will mail a copy of the move to your opponent. If you select Exit without having selected Mail Move then no move will be made. 😭

Answering a Move

When you receive a message from an opponent containing a move in one of your games, simply pipe the message through cmail. In some mailers this is as simple as typing | cmail when viewing the message, while in others you may have to save the message to a file and do cmail < file at the command line. In either case cmail will display the game using XBoard. If you didn't exit XBoard when you made your first move then cmail will do its best to use the existing XBoard instead of starting a new one. As before, simply make a move and select Mail Move from the File menu. See File Menu. cmail will try to use the XBoard that was most recently used to display the current game. This means that many games can be in progress simultaneously, each with its own active XBoard. 💅

If you want to look at the history or explore a variation, go ahead, but you must return to the current position before XBoard will allow you to mail a move. If you edit the game's history you must select Reload Same Game from the File menu to get back to the original position, then make the move you want and select Mail Move. As before, if you decide you aren't ready to make a move just yet you can either select Exit without sending a move or just leave XBoard running until you are ready.

Multi-Game Messages

It is possible to have a cmail message carry more than one game. This feature was implemented to handle IECG (International Email Chess Group) matches, where a match consists of one game as white and one as black, with moves transmitted simultaneously. In case there are more general uses, cmail itself places no limit on the number of black/white games contained in a message; however, XBoard does.

Completing a Game

Because XBoard can detect checkmate and stalemate, cmail handles game termination sensibly. As well as resignation, the Action menu allows draws to be offered and accepted for cmail games. 🎀

For multi-game messages, only unfinished and just-finished games will be included in email messages. When all the games are finished, they are archived in the user's archive directory, and similarly in the opponent's when he or she pipes the final message through cmail. The archive file name includes the date the game was started.

Known CMail Problems

It's possible that a strange conjunction of conditions may occasionally mean that cmail has trouble reactivating an existing XBoard. If this should happen, simply trying it again should work. If not, remove the file that stores the XBoard's PID (game.pid) or use the -xreuse option to force cmail to start a new XBoard. 🙈

Versions of cmail after 2.16 no longer understand the old file format that XBoard used to use and so cannot be used to correspond with anyone using an older version.

Versions of cmail older than 2.11 do not handle multi-game messages, so multi-game correspondence is not possible with opponents using an older version.

✨ OTHER PROGRAMS YOU CAN USE WITH XBOARD ✨

Okay bestie, so XBoard is not a solo act 💅 — here's a lil roster of other programs you can pair it with, and honestly? The range is giving.

🐧 GNU Chess

The GNU Chess engine is available from:

ftp://ftp.gnu.org/gnu/gnuchess/

You can use XBoard to play a game against GNU Chess, or to interface GNU Chess to an ICS. Both. You can do both. Iconic.

🧚 Fairy-Max

Fairy-Max is a derivative from the once World's smallest Chess program micro-Max, which measures only about 100 lines of source code. The main difference with micro-Max is that Fairy-Max loads its move-generator tables from a file, so that the rules for piece movement can be easily configured to implement unorthodox pieces. That's the whole glow-up right there.

Fairy-Max can therefore play a large number of variants, normal Chess being one of those. In addition it plays Knightmate, Capablanca and Gothic Chess, Shatranj, Courier Chess, Cylinder chess, Berolina Chess, while the user can easily define new variants. It can be obtained from:

http://home.hccnet.nl/h.g.muller/dwnldpage.html

🌸 HoiChess

HoiChess is a not-so-very-strong Chess engine, which comes with a derivative HoiXiangqi, able to play Chinese Chess. It can be obtained from the standard Linux repositories through:

sudo apt-get install hoichess

One command. That's it. Slay.

🔥 Crafty

Crafty is a chess engine written by Bob Hyatt. You can use XBoard to play a game against Crafty, hook Crafty up to an ICS, or use Crafty to interactively analyze games and positions for you. Three whole modes, main character energy fr fr 💖

Crafty is a strong, rapidly evolving chess program. This rapid pace of development is good, because it means Crafty is always getting better. This can sometimes cause problems with backwards compatibility, but usually the latest version of Crafty will work well with the latest version of XBoard. Crafty can be obtained from its author's FTP site:

ftp://ftp.cis.uab.edu/hyatt/

To use Crafty with XBoard, give the -fcp and -fd options as follows, where <crafty's directory> is the directory in which you installed Crafty and placed its book and other support files.

©️ COPYRIGHT

Legal o'clock, bestie. Pay attention but don't panic, it's all chill in here.

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Digital not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.

Digital disclaims all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall Digital be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software.

Published by the Free Software Foundation 59 Temple Place - Suite 330 Boston, MA 02111-1307 USA

Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the section entitled ``GNU General Public License,'' is included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the section entitled ``GNU General Public License,'' and this permission notice, may be included in translations approved by the Free Software Foundation instead of in the original English.

📜 GNU GENERAL PUBLIC LICENSE

Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. No edits. Zero. Don't touch it. 🚫

The GNU General Public License is a free, copyleft license for software and other kinds of works.

The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program -- to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too. Bestie, you can literally use it on your own stuff. Pass it on.

When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things.

To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore, you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the freedom of others.

For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights. Reciprocity, but make it software. 🦋

Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License giving you legal permission to copy, distribute and/or modify it.

For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be attributed erroneously to authors of previous versions. Mark your edits, bestie. Don't let your chaos get blamed on someone else.

Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software. The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as needed to protect the freedom of users.

Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the program non-free.

The precise terms and conditions for copying, distribution and modification follow.

🔎 Definitions

``This License'' refers to version 3 of the GNU General Public License.
``Copyright'' also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.
**The Program''** refers to any copyrightable work licensed under this License. Each licensee is addressed as you''. Licensees'' and recipients'' may be individuals or organizations.
To **modify''** a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a modified version'' of the earlier work or a work ``based on'' the earlier work.
A ``covered work'' means either the unmodified Program or a work based on the Program.
To ``propagate'' a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well.
To ``convey'' a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying. So like, just vibing on a network? Not conveying. Handing over a copy? Conveying.
An interactive user interface displays ``Appropriate Legal Notices'' to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion. Yep — a menu item totally counts. That's the vibe check.

🗂️ Source Code

The source code''** for a work means the preferred form of the work for making modifications to it. **Object code'' means any non-source form of a work.

A ``Standard Interface'' means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language.

okay so picking up right where we left off in the System Libraries saga 🫶 stay with me bestie, we're so close

The "System Libraries" of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A "Major Component", in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it. 💅

The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work. 🦋

The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source.

The Corresponding Source for a work in source code form is that same work. periodt. ✨

💖 Basic Permissions

All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work. This License acknowledges your rights of fair use or other equivalent, as provided by copyright law. 🫶

You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you.

Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary. 💀

🛡️ Protecting Users' Legal Rights From Anti-Circumvention Law

No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures.

When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures. 👑

🎀 Conveying Verbatim Copies

You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you:

conspicuously and appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and
give all recipients a copy of this License along with the Program. 💌

You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee. 💸

🦋 Conveying Modified Source Versions

You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions:

The work must carry prominent notices stating that you modified it, and giving a relevant date.
The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to "keep intact all notices".
You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it.
If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so. 🙈

A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an "aggregate" if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate. ✨

🌈 Conveying Non-Source Forms

You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways:

a. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange.
b. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge.
c. Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b.
d. Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements. 👑
e. Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d.

A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work. 🍓

A "User Product" is either (1) a "consumer product", which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, "normally used" refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product. 💜

💾 `Installation Information` — the saga continues 🫶

Okay so when we say Installation Information for a User Product, we mean literally any methods, procedures, authorization keys, or other info you need in order to install and run modified versions of a covered work in that User Product, starting from a modified version of its Corresponding Source. And bestie, that info has to be enough — it must be sufficient to guarantee that the modified object code keeps functioning and that nothing prevents or interferes with it solely because a modification was made. 💅

If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and that conveying happens as part of a transaction where the right of possession and use of the User Product gets transferred to the recipient in perpetuity or for a fixed term (no matter how that transaction is characterized, we see you 👀), then the Corresponding Source conveyed under this section must come with the Installation Information. But — plot twist — this requirement does not apply if neither you nor any third party keeps the ability to install modified object code on the User Product. Example: the work has been installed in ROM. 📀

Also, the requirement to hand over Installation Information does not mean you have to keep providing support service, warranty, or updates for a work that's been modified or installed by the recipient, or for the User Product in which it was modified or installed. And network access may be denied when the modification itself materially and adversely affects the operation of the network, or violates the rules and protocols for communication across the network. 🚫🌐

Any Corresponding Source conveyed, and any Installation Information provided, in accord with this section has to be in a format that is publicly documented — and with an implementation available to the public in source code form — and it must require no special password or key for unpacking, reading or copying. 🔓✨

📝 Additional Terms

Additional permissions are terms that supplement this License's terms by making exceptions from one or more of its conditions. If additional permissions apply to the entire Program, they're treated as though they were included in this License, to the extent they're valid under applicable law. If additional permissions apply to only part of the Program, that part may be used separately under those permissions — but the entire Program stays governed by this License without regard to the additional permissions. 🎀

When you convey a copy of a covered work, you may, at your option, remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work — sneaky like that. 🙈) You may also place additional permissions on material you added to a covered work, for which you have or can give appropriate copyright permission.

Notwithstanding any other provision of this License, for material you add to a covered work, you may — if authorized by the copyright holders of that material — supplement the terms of this License with terms:

Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or
Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or
Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or
Limiting the use for publicity purposes of names of licensors or authors of the material; or
Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or
Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors.

All other non-permissive additional terms are considered further restrictions within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it's governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document — provided that the further restriction does not survive such relicensing or conveying. ✨

If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms. No hiding them in the group chat, bestie. 💬

Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions — the above requirements apply either way.

🚫 Termination

You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License — including any patent licenses granted under the third paragraph of section 11. 💀

However! If you cease all violation of this License, then your license from a particular copyright holder is reinstated:

(a) provisionally — unless and until the copyright holder explicitly and finally terminates your license; and
(b) permanently — if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. ⏳

And moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. 🕐

Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. And if your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10. Sorry babe, that's just how it is. 🫶

📦 Acceptance Not Required for Having Copies

You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. 🌀

But here's the thing — nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. So, by modifying or propagating a covered work, you indicate your acceptance of this License to do so. No cap, that's the deal. ✅

🔁 Automatic Licensing of Downstream Recipients

Every single time you convey a covered work, the recipient automatically receives a license from the original licensors to run, modify and propagate that work, subject to this License. And no, you are not responsible for enforcing compliance by third parties with this License. Not your job, not your problem. 💅

An entity transaction is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph — plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts. 🏢➡️🏢

You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it. 🛑

⚖️ Patents

A contributor is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's contributor version. 👑

A contributor's essential patent claims are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version. But they do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, control includes the right to grant patent sublicenses in a manner consistent with the requirements of this License. 🧠

Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version. 🌍✨

Okay bestie, we're in the home stretch of the legal arc 🎀 and it's giving "my lawyer wrote this at 2am." Buckle up, the vibes are ✨legally binding✨ but I'm gonna walk you through it like we're gossiping. 💅

Real quick, for the next three paragraphs specifically, here's the vocab we're using — no cap:

A "patent license" is any express agreement or commitment, no matter what you call it, to not enforce a patent. Think: an express permission to practice a patent, or a covenant not to sue for patent infringement. 🤝

And to "grant" such a patent license to a party means you're making that kind of agreement or commitment not to enforce a patent against them. Periodt.

Paragraph numero uno: If you convey a covered work while knowingly relying on a patent license, AND the Corresponding Source of the work isn't available for anyone to copy — free of charge, under the terms of this License, through a publicly available network server or other readily accessible means — then you've gotta do one of these three things:

cause the Corresponding Source to be so available, or
arrange to deprive yourself of the benefit of the patent license for this particular work, or
arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients.

And "Knowingly relying" means you have actual knowledge that — but for the patent license — your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid. 🫠

Paragraph two, the glow-up clause: If — pursuant to or in connection with a single transaction or arrangement — you convey, or propagate by procuring conveyance of, a covered work, and you grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it. 💖 Iconic behavior, honestly.

Paragraph three, the mean one: A patent license is "discriminatory" if it doesn't include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. 🚫

You may NOT convey a covered work if you're a party to an arrangement with a third party that's in the business of distributing software, where: - you make payment to the third party based on the extent of your activity of conveying the work, and - the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license: - (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or - (b) primarily for and in connection with specific products or compilations that contain the covered work, …unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007. 📅 (Yes, that date matters. Don't @ me.)

And finally: nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. 🫶

✨ No Surrender of Others' Freedom. ✨

If conditions get imposed on you — whether by court order, agreement or otherwise — that contradict the conditions of this License, they do not excuse you from the conditions of this License. 😤

And if you literally cannot convey a covered work in a way that satisfies simultaneously your obligations under this License and any other pertinent obligations, then as a consequence — you may not convey it at all. 💀

For example: if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program. So… don't do that. 🙈

🌈 Use with the GNU Affero General Public License.

Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. 🦋

The terms of this License will continue to apply to the part which is the covered work, BUT the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such. 🌐

⭐ Revised Versions of this License.

The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Those new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. 💜

Each version is given a distinguishing version number. So:

If the Program specifies that a certain numbered version of the GNU General Public License "or any later version" applies to it, you get to pick — follow the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. ✨
If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation. 👑

If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program. 🤝

Later license versions may give you additional or different permissions. However — and this is the important bit — no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version. 🫶

💀 Disclaimer of Warranty.

Okay so in the original this whole thing is in ALL CAPS because that's the legal-shouting convention, and it means business:

THERE IS NO WARRANTY FOR THE PROGRAM, to the extent permitted by applicable law. Except when otherwise stated in writing, the copyright holders and/or other parties provide the program "AS IS" without warranty of any kind — either expressed or implied — including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose.

The entire risk as to the quality and performance of the Program is with you. 😭 And should the Program prove defective, you assume the cost of all necessary servicing, repair or correction.

No refunds, bestie. It's free software. You knew the vibes. 💅

😭 Limitation of Liability.

IN NO EVENT — unless required by applicable law or agreed to in writing — will any copyright holder, or any other party who modifies and/or conveys the Program as permitted above, be liable to you for damages. That includes any general, special, incidental or consequential damages arising out of the use or inability to use the Program (including but not limited to loss of data or data being rendered inaccurate, losses sustained by you or third parties, or a failure of the Program to operate with any other programs) — even if such holder or other party has been advised of the possibility of such damages. 💀

🧚 Interpretation of Sections 15 and 16.

If the disclaimer of warranty and limitation of liability provided above can't be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program — unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. ⚖️

And now the wholesome part where they teach you how to give your own baby program the same glow-up: 🥹

If you develop a new program and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. 🌸

To do so, attach the following notices to the program. It's safest to attach them to the start of each source file to most effectively state the exclusion of warranty, and each file should have at least the "copyright" line and a pointer to where the full notice is found. ✨

ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
Copyright (C) YEAR NAME OF AUTHOR

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see `http://www.gnu.org/licenses/'.

Also add info on how to contact you by electronic and paper mail. 📬

If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:

PROGRAM Copyright (C) YEAR NAME OF AUTHOR
This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.

The hypothetical commands show w' and show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different — for a GUI interface, you'd use an "about box". 🎀

You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more info on this, and how to apply and follow the GNU GPL, see http://www.gnu.org/licenses/. 👑

And a very important heads-up: The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If that's what you want to do — use the GNU Lesser General Public License instead of this License. But first, please read http://www.gnu.org/philosophy/why-not-lgpl.html. 🙈

And that's a wrap on the whole entire xboard(6) page, bestie!! 🎉💖 You made it all the way to the end of a genuinely enormous manual and I'm so proud of you. 🥹 This final part came from the GNU manual collection — it's xboard(6), section 6 (games/entertainment, iykyk 🎮), and the footer's date field is literally still the unexpanded $Date: RCS keyword, which is such a mood for software that's been slaying since the last millennium. 👑✨ Go play some chess. 🦋♟️

📦 where this page comes from

debian bookworm: xboard 4.9.1-2+b1 · GPL-3.0-or-later AND DEC-license
debian trixie: xboard 4.9.1-3 · GPL-3.0-or-later AND DEC-license
ubuntu jammy: xboard 4.9.1-2build1 · GPL-3.0-or-later AND DEC-license
ubuntu noble: xboard 4.9.1-2build3 · GPL-3.0-or-later AND DEC-license
ubuntu questing: xboard 4.9.1-3
ubuntu resolute: xboard 4.9.1-3.1 · GPL-3.0-or-later AND DEC-license
ubuntu stonking: xboard 4.9.1-5 · GPL-3.0-or-later AND DEC-license
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-18: a language model's rewrite of the original, under its terms