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 between 1977 and 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.

The game takes place in the Zork calendar year 948 GUE (although the passage of time is not notable in gameplay). The player steps into the deliberately vague role of an "adventurer". The game begins near a white house in a small, self-contained area. Although the player is given little instruction, the house provides an obvious point of interest.