In QIX, the objective is to fence in a large majority of the play field and defeat the QIX. Players must close in the large enemy, the QIX, in a closed space without it touching the player or the lines drawn by the player. Every time the player creates a closed space, they are awarded points and the space becomes solid so the QIX can no longer pass through it. Other enemies besides the QIX exist in the form of Sparx. The Sparx moves on the lines that the player draws and can defeat the player in the same way as the QIX.
QIX was originally released in arcades in 1981 but Taito ported the game to a large variety of consoles such as the Atari 5200, Atari 400/800, Apple II, Commodore 64, DOS, Amiga (with new graphics), Apple IIGS, NES, and Atari Lynx. Nintendo also developed a Game Boy version that featured Mario, Luigi, and Princess Peach.