Publisher Infocom released Zork: The Great Underground Empire in 1980. One of the earliest examples of interactive fiction, Zork played a pivotal role in the development of the text-adventure genre which peaked in popularity during the 1980s. The player begins in a forest clearing next to an abandoned white house. Located inside the house is a passageway into the Great Underground Empire where the majority of the game takes place. The objective is to find twenty treasures hidden in the underground labyrinth and return to the abandoned house alive. Along the way players solve puzzles, battle monsters, gather items, and avoid venturing into dark areas for fear of the infamous grue. At its release Zork received critical acclaim for its writing quality, story-telling ability and sense of humor. Developed before advanced graphics were available on home computers, Zork is completely text-based. Detailed prose describes the scene and the player's imagination creates the visual. Players control their character by typing commands into a prompter. Zork features a sophisticated parser which recognizes full sentences, a major innovation at a time when most parsers recognized commands of only two words.
Zork is considered the epitome of the text-adventure genre. It was the first commercially successful text adventure and captivated a generation of computer gamers. Remembered fondly for its simplicity, innovative puzzles, and witty descriptions, Zork is considered a classic in the gaming industry. The franchise culminated in fourteen installments including the online game, Legends of Zork, which closed in 2011.