ADVENT(6)

💖 ADVENT(6) — bestie edition 💖

okay so. sit down. hydrate. because we're about to talk about advent, aka Colossal Cave Adventure, and this is literally the blueprint, the moment, the origin story. ✨

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✨ NAME ✨

advent — Colossal Cave Adventure, the mother of us all. no cap. 👑

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🌸 SYNOPSIS 🌸

advent [-l logfile] [-o] [-r savefile] [-a savefile] [script...]

look at her. one line. iconic.

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🦋 DESCRIPTION 🦋

The original Colossal Cave Adventure dropped in 1976-1977, and it is the origin of, like, every later text adventure, every dungeon-crawl (computer) game, and every computer-hosted roleplaying game. the way that one program birthed an entire genre?? main character energy fr fr. 🔥

This right here is the last version released by Crowther & Woods, its original authors, in 1995. it's been known as "adventure 2.5" and "430-point adventure". wanna know what changed since the 350-point original? type news at the command prompt, bestie, it's all in there. 📜

small tea: there's an adventure in the BSD games package that's a C port by Jim Gillogly of the 1977 version. to avoid a name collision, this game builds as advent — which reflects the fact that the PDP-10 it originally ran on limited filenames to 6 characters. historically constrained and still slaying. 💅

This version is released as open source with the permission and encouragement of the original authors. 🫶 (yes, they said yes, we're allowed to be here.)

Unlike the original, this version has a command prompt AND supports use of your arrow keys to edit your command line in place. Basic Emacs keystrokes are supported, and your up/down arrows access a command history. glow-up honestly. ⭐

Some minor bugs and message typos have been fixed. Otherwise, the version command is almost the only way to tell you're not running Don's 1977 version — until you get to the new cave sections added for 2.5. 🕳️

To exit the game, type Ctrl+D (EOF). that's your escape hatch, don't forget it.

There have been no gameplay changes. periodt. 🎀

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💅 OPTIONS 💅

• -l — log commands to the specified file. receipts, but for your cave journey. 📝
• -r — restore game from the specified save file. welcome back, queen.
• -a — load from the specified save file and autosave to it on exit or signal. she remembers everything so you don't have to. ✨
• -o — old-style. reverts some minor cosmetic fixes in game messages. restores the original interface, no prompt or line editing. also ignores new-school one-letter commands l, x, g, z, i. also case-smashes and truncates unrecognized text when echoed. it's giving time capsule. 🕰️

Normally, game input is taken from standard input. if script file arguments are given, input is taken from them instead. and a script file argument of - is taken as a directive to read from standard input. cute little handshake. 🤝

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💀 BUGS 💀

The binary save file format is fragile, dependent on your machine's endianness, and unlikely to survive through version bumps. 😭 There are version and endianness checks when attempting to restore from a save, so at least she warns you before things get weird.

The input parser was the first attempt ever at natural-language parsing in a game, and it has some known deficiencies. later text adventures distinguished between transitive and intransitive verbs — Adventure's grammar distinguishes only between motion and action verbs. here's the whole situation:

• Motions are always immediate in their behavior, so both ACTION MOTION and MOTION ACTION (and even MOTION NOUN and MOTION MOTION) are invariably equivalent to MOTION (thus GO NORTH means NORTH and JUMP DOWN means JUMP).
• With actions and nouns, the parser collects words until it's seen one of each, and then dispatches; if it reaches the end of the command without seeing a noun, it'll dispatch an "intransitive" action. this makes ACTION1 ACTION2 equivalent to ACTION2 (thus TAKE INVENTORY means INVENTORY), and NOUN ACTION equivalent to ACTION NOUN.

Thus you get anomalies like "eat building" interpreted as a command to move to the building. 🏠 these should not be reported as bugs; instead, consider them historical curiosities. they're vintage. they're lore. leave them alone. 🙈

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📮 REPORTING BUGS 📮

Report bugs to Eric S. Raymond at esr@thyrsus.com. the project page is at http://catb.org/~esr/open-adventure. go say hi if you find something real (not a historical curiosity, bestie, read the section above first). 💌

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👀 SEE ALSO 👀

wumpus(6), adventure(6), zork(6), rogue(6), nethack(6).

the whole ancestral friend group. go visit them all. 🧚

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mwah, that's the whole page. ADVENT(6), dated 2026-03-27, and it's still eating after all these years. take care of your save files, log your commands, and type news at the prompt like I told you. bye bestie!! 🌈💖