Controls consist of a four-direction joystick and two buttons: “Slow Draw” and “Fast Draw”.
The player controls a diamond-shaped marker that initially moves along the edges of the playfield. Holding down one of the draw buttons allows the marker to draw a line (Stix) in unclaimed territory in an attempt to create a closed shape. Once an area is captured, it is filled with color and points are awarded based on the area claimed and drawing speed. Areas captured entirely with Slow Draw (orange-red in the screenshot) are worth double. The titular Qix is a colorful geometric figure in constant and random motion. The Qix will not actively seek out the marker, and it will not harm the marker if it collides with it while the marker is traversing the edge of the playfield or of any captured area. However, if the Qix collides with the marker as it is drawing a Stix before a new area is captured (or it touches the exposed Stix), one life is lost.