Adventure

Adventure, credited to William Crowther and Don Woods and dated here to 1977, is nothing less than the fountainhead of an entire genre. Often known as Colossal Cave Adventure or simply ADVENT, it began as Crowther's text-based exploration of a real cave system, later expanded by Woods into a fantasy quest full of treasure, puzzles, and hazards. It is the game that gave us the parser-driven "you are standing in an open field" formula and the immortal maze of twisty little passages, all alike.

Everything that followed in interactive fiction, from Zork to the Sierra and LucasArts adventures, traces its lineage back here. There are no graphics, only typed commands and evocative room descriptions, yet its sense of discovery and its cave to map by hand still cast a spell. Playing it today is as much a pilgrimage as a game session: it is a genuine piece of computing history, remarkably approachable, and a reminder of how much imagination a few lines of text can conjure.