In computing, Xyzzy is sometimes used as a metasyntactic variable or as a video game cheat code. Xyzzy comes from the Colossal Cave Adventure computer game, where it is the first "magic string" that most players encounter (others include "plugh" and "plover").
Modern usage is primarily from one of the earliest computer games, Colossal Cave Adventure, in which the idea is to explore a cave with many rooms, collecting the treasures found there. By typing "xyzzy" at the appropriate time, the player could move instantly between two otherwise distant points. As Colossal Cave Adventure was both one of the first adventure games and one of the first interactive fiction pieces, hundreds of later interactive fiction games included responses to the command "xyzzy" in tribute.
The origin of the word "xyzzy" has been the subject of debate. According to Ron Hunsinger, the sequence of letters "XYZZY" has been used as a mnemonic to remember the process for computing cross products. Will Crowther, the author of Colossal Cave Adventure, states that he was unaware of the mnemonic, and that he "made it up from whole cloth" when writing the game.