Zork I: The Great Underground Empire was the first game published in the popular Zork trilogy, and the first game by Infocom. It is recognized as one of the most memorable and influential text adventures of all time.
Inspired by the first text based adventure game (called "Colossal Cave Adventure"), Zork was originally a single game written and distributed on mainframes and minicomputers in the 1970's by a quartet of MIT students who were part of the school's Dynamic Modelling Group.
Later, Zork ported over and expanded into a larger trilogy of games for a wide variety of home PCs via the Z-Machine Interpreter. The reason for the expansion was because the original system did not have enough memory or disk space to handle the entire game. After the release of Zork II and Zork III, the first game was retroactively renamed Zork I.
The entire game: objects, environments, characters, actions, are described with text. The player moves through the environment by typing directional commands (such as "north", "south", "east", or "west") to move to different locations, called "rooms". Other commands for manipulating objects were more general ("take", "get", "drop", "open", "close") and while some were more specific that only made sense for specific objects (such as "light the lamp").
Players start next to a white house. From there, they explore their environment and collect items. Some items have no functional purpose, but others are used to solve intricate puzzles. The majority of the game takes place underground. If there is no light sources, within a few moves the player will be eaten by a grue. When this happens, the game will restart and any previous objects held in the players inventory lie scattered around into other (non-default) locations. The ultimate goal is to collect the Twenty One Treasures of Zork and earn the title of "Master Adventurer," which can be done is as few as 231 moves.
There's not much of a storyline in the game itself. However there is an amusing backstory detailing the history of the (now-fallen) Great Underground Empire that is revealed through items in the game. Much of the fun of the game is reading the witty descriptions of the objects and environment.
Zork inspired other text-based games also produced by Infocom, and even some games with graphics. Some of them are: The Enchanter Trilogy, Wishbringer, the Zork Quest and Anthology series, and several others.
- This game (and other text based adventure games) inspired the song "It Is Pitch Dark" by MC Frontalot. It contains many references to Zork and other Infocom games, including the lines "You Are likely to be eaten by a grue", reading a pamphlet that urges low cunning, and even the Babel Fish sequence from The Hitchhikers Guide To The Galaxy Infocom game.
- If the player types the word "plugh," the game will respond with "A hallow voice says "fool." This is a reference to the "A hollow voice says 'plugh'" line in Colossal Cave Adventure.
- The game contains multiple uses of the phrase "Hello, sailor," but the response to this is always "Nothing happens here." This continues throughout the Zork series, until it finally becomes useful in Zork III.
- Zork I was one of the first games added to IGN's Video Gaming Hall of Fame in 2009.
- Zork is available to play in Call Of Duty: Black Ops as a side game that unlocks "Eaten by a Grue," a special feature in the game.
"It is pitch black, you are likely to be eaten by a grue."