Qix is a 1981 puzzle video game developed by husband and wife team Randy and Sandy Pfeiffer and published in arcades by Taito America. Qix is one of a handful of games made by Taito's American division. At the start of each level, the playing field is a large, empty rectangle, containing the Qix, a stick-like entity that performs graceful but unpredictable motions within the confines of the rectangle. The objective is to draw lines that close off parts of the rectangle to fill in a set amount of the playfield.

The player controls a marker that can move around the edges of the rectangle. Holding down one of the draw buttons allows the marker to move into unclaimed territory and draw lines (Stix) in an attempt to create a closed shape. If completed, the captured area (defined as the side opposite of where the Qix is) becomes filled in with a solid color and points are awarded. To complete a level, the player must claim 65% of the playfield (adjustable by the arcade operator to be between 50% and 90%).