Coriolis soccer is a football code played on the floor of a rotating habitat, in which the sideways deflection of the ball in flight is a governing feature of play rather than an incidental one. It is among the principal spectator sports of Coriopolis, whose stadium sits in the northern city.

Any object moving freely within a rotating frame is deflected: a ball rising is carried west, a ball falling is carried east, and a ball traveling east is effectively lightened while one traveling west is made heavier. The relevant magnitudes are set out under turning bias. Over the length of a kicked pass the effect is large enough to see and far too large to ignore.

The consequence is that the code has no symmetry between its ends. A shot struck toward the east behaves unlike the same shot struck west; a high ball and a driven ball curve in opposite directions; and a goalkeeper’s positioning depends on which way the attack is running. Play accordingly favors athletes who have grown up with the deflections, and visitors from Earth or from habitats with different rotation rates are notoriously poor judges of a long ball.