Zork is one of the earliest interactive fiction computer games, with roots drawn from the original genre game, Colossal Cave Adventure. The first version of Zork was written in 1977–1979 using the MDL programming language on a DEC PDP-10 computer. The authors—Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling—were members of the MIT Dynamic Modelling Group.

When Zork was published commercially in 1980, it was split up into three games: Zork: The Great Underground Empire - Part I (later known as Zork I), Zork II: The Wizard of Frobozz, and Zork III: The Dungeon Master.  This was due to the size of the game and its inability to fit on floppy disks of the time.

The player begins at the bottom of the Endless Stair from Zork II.  You must get past the Guardians of Zork, with the complete garb of the Dungeon Master, and then endure a final test.  Once the player has all the items, they must give the waybread to the elderly man in the Engravings Room, who reveals himself as the Dungeon Master once fed, to find the doorway leading to the final hallway.  This eventually leads to a door revealing the Treasury of Zork, which contains the wealth of the Great Underground Empire as well as a controlling share in FrobozzCo International. After this victorious discovery, the Dungeon Master appears and transforms the player into a duplicate of himself, signifying the player's succession to his position.

"Feelies" were not included until the 1984 "Grey box" re-release.