The Lurking Horror is an interactive fiction computer game released by Infocom in 1987. The game was written by Dave Lebling and inspired by the horror writings of H. P. Lovecraft (including his Cthulhu Mythos). Like most of Infocom's games, it was released for several platforms simultaneously thanks to the portable Z-machine.
The original release included versions for DOS, the Apple II, Atari ST, Atari 8-bit family and Commodore 64. Later, it was ported to the Amiga with the addition of sound effects, making it the first title with that feature. The effects would play at appropriate times in the game in an effort to intensify the horror atmosphere. This marked one of the few major additions to the Z-machine with the exception of graphics; traditionally, Infocom had eschewed such changes in favor of expanding the parser capacity and overall size of game files.
Despite its relatively high sales figures, Lurking Horror was the only horror game ever released by Infocom. It is Infocom's twenty-sixth game. Infocom rated it as "Standard" in terms of difficulty.
The game starts with the player trying to finish a term paper at G.U.E. Tech, a large MIT-like American university. The player has braved a snowstorm to travel to the school's computer lab to work on the report. The document is now mangled beyond repair, however; with the help of a hacker, the player finds that the file has been partially overwritten by the Department of Alchemy's files. Although the game begins as a quest to try to salvage the term paper, alarming events soon unfold, revealing a powerful evil within the school's depths.
What began as a mere snowstorm has strengthened into a full-force blizzard. The player must traverse the University grounds in an attempt to recover the term paper's data. Much of the campus is deserted and covered in snowdrifts, rendering walkways impassable. The only accessible avenues are steam tunnels and a small complex of buildings. In the course of unraveling the mystery, the player encounters demons, zombies and sinister references to a recent campus suicide. Failing to set things right in the hidden passages beneath the school will result in a literal fate worse than death.