Xyzzy is a magic word from the Colossal Cave Adventure computer game. In computing, the word is sometimes used as a metasyntactic variable or as a video game cheat code, the canonical "magic word".
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 Rick Adams, the sequence of letters "XYZZY" has been used as a mnemonic to remember the process for computing cross products. Crowther, 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.
Xyzzy has been implemented as an undocumented no-op command on several operating systems; in the 16-bit version of Data General's AOS, for example, it would typically respond "Nothing happens", just as the game did if the magic was invoked at the wrong spot or before a player had performed the action that enabled the word. The 32-bit version, AOS/VS, would respond "Twice as much happens". On several computer systems from Sun Microsystems, the command "xyzzy" is used to enter the interactive shell of the U-Boot bootloader. Early versions of Zenith Z-DOS (a re-branded variant of MS-DOS 1.25) had the command "xyzzy" which took a parameter of "on" or "off". Xyzzy by itself would print the status of the last "xyzzy on" or "xyzzy off" command.
According to Brantley Coile, the Cisco PIX firewall had a xyzzy command that simply said "Nothing happens." He also put the command into the Coraid VSX to escape the CLI and get into the shell. It would announce "Foof! You are in a directory. There are files here." The new California Coraid management, made development to change the string to "/exportmode" and get rid of the "Foof!" message Since regaining ownership of the Coraid software, the command is being returned to the system and now, in VSX release 8, the response is ">>Foof!<< You are in a debris room.".
Within the low-traffic Usenet newsgroup alt.xyzzy, the word is used for test messages, to which other readers (if there are any) customarily respond, "Nothing happens" as a note that the test message was successfully received. In the Internet Relay Chat client mIRC and Pidgin, entering the undocumented command "/xyzzy" will display the response "Nothing happens". The string "xyzzy" is also used internally by mIRC as the hard-coded master encryption key that is used to decrypt over 20 sensitive strings from within the mirc.exe program file.
A "deluxe chatting program" for DIGITAL's VAX/VMS written by David Bolen in 1987 and distributed via BITNET took the name xyzzy. It enabled users on the same system or on linked DECnet nodes to communicate via text in real time. There was a compatible program with the same name for IBM's VM/CMS.
xYzZY is used as the default boundary marker by the Perl HTTP::Message module for multipart MIME messages, and was used in Apple's AtEase for workgroups as the default administrator password in the 1990s.
The Hewlett-Packard 9836A computer with HPL 2.0 programming language has XYZZY built into the HPL language itself with the result of "I see no cave here." when used. The same message is returned from HP 3458A and HP 3245A instruments when queried with XYZZY via the HPIB bus.
In most versions of the Ingres dbms, "select xyzzy('')" returns "Nothing happens." However, "select xyzzy('wim')" returns "Nothing happens to Wim". The xyzzy() function has been part of the Ingres product since at least version 5 (late 1980s), but was removed from the main codeline sometime in the early 2000s. While talking to one of the members of the Ingres development team, Wim de Boer, at that time the secretary of the Ingres Users Group Nederland (IUGN), mentioned the removal of this Easter egg. This developer, who was a frequent speaker on the events organised by the IUGN, somehow managed to put the function back into the product and—especially for Wim—added handling for the 'wim' value of the parameter.
The popular Minesweeper game under older versions of Microsoft Windows had a cheat mode triggered by entering the command
xyzzy, then pressing the key sequence shift and then enter, which turned a single pixel in the top-left corner of the entire screen into a small black or white dot depending on whether or not the mouse pointer is over a mine. This easter egg was present in all Windows versions through Windows XP Service Pack 3, but under Windows 95, 98 and NT 4.0 the pixel was visible only if the standard Explorer desktop was not running. The easter egg does not exist in versions after Windows XP SP3.
In the game Zork, typing xyzzy and pressing enter produces the response: "A hollow voice says 'fool'". The command commonly produces a humorous response in other Infocom games and text adventures, leading to its usage in the title of the interactive fiction competition, the XYZZY Awards.
In Hugo's House of Horrors, typing xyzzy gives the message "We are getting desperate, aren't we!".
In Dungeons and Dragons Online, Xy'zzy is the nigh-invulnerable raid boss in the Hound of Xoriat adventure.
In Primordia, one is able to get a bonus short scene featuring a shout-out to Colossal Cave Adventure as a form of non-playable text-adventure, which is accessible by typing 'xyzzy' in Memorious's data-kiosk.
In the video game Deus Ex, protagonist JC Denton is trying to make contact with the Mole People, and when their representative, Curly, prompts for a password to reveal the Mole People's hideout, Denton tries "xyzzy" if the password has not been obtained by him beforehand. Curly denies this attempt, as one would expect.
Andrew Sega released an album under the name XYZZY.