The prototypical computer adventure game, first designed by Will Crowther on the PDP-10 in the mid-1970s as an attempt at computer-refereed fantasy gaming, and expanded into a puzzle-oriented game by Don Woods at Stanford in 1976. (Woods had been one of the authors of INTERCAL.) Now better known as Adventure or Colossal Cave Adventure, but the TOPS-10 operating system permitted only six-letter filenames in uppercase. See also vadding, Zork, and Infocom.
Figure 1. Screen shot of the original ADVENT game
Orange River Chamber You are in a splendid chamber thirty feet high. The walls are frozen rivers of orange stone. An awkward canyon and a good passage exit from east and west sidesof the chamber. A cheerful little bird is sitting here singing. >drop rod Dropped. >take bird You catch the bird in the wicker cage. >take rod Taken. >w At Top of Small Pit At your feet is a small pit breathing traces of white mist. A west passage ends here except for a small crack leading on. Rough stone steps lead down the pit. >down In Hall of Mists You are at one end of a vast hall stretching forward out of sight to the west. There are openings to either side. Nearby, a wide stone staircase leads downward. The hall is filled with wisps of white mist swaying to and fro almost as if alive. A cold wind blows up the staircase. There is a passage at the top of a dome behind you. Rough stone steps lead up the dome.
This game defined the terse, dryly humorous style since expected in text adventure games, and popularized several tag lines that have become fixtures of hacker-speak: “A huge green fierce snake bars the way!” “I see no X here” (for some noun X). “You are in a maze of twisty little passages, all alike.” “You are in a little maze of twisty passages, all different.” The ‘magic words’ xyzzy and plugh also derive from this game.
Crowther, by the way, participated in the exploration of the Mammoth & Flint Ridge cave system; it actually has a Colossal Cave and a Bedquilt as in the game, and the Y2 that also turns up is cavers' jargon for a map reference to a secondary entrance.
ADVENT sources are available for FTP at ftp://ftp.wustl.edu/doc/misc/if-archive/games/source/advent.tar.Z. You can also play it as a Java applet. There is a good page of resources at the Colossal Cave Adventure Page.