Zap ball was similar to racquetball, with a hand-held zap ball funnel substituted for a racket, with scoring similar to tennis’ counting of games, sets and matches. During play, the serving player launched his zap ball from a funnel and aimed such that the ball ricocheted onto two walls, then was caught by the opposing player’s funnel. Lines on the floor defined player positions. The sport was played professionally in the Federation on a zap ball court in an interplanetary championship, but was also played recreationally.
In 2267, Montgomery Scott swapped a duty shift with Hikaru Sulu in order to play a game of zap ball with a female crewman aboard the USS Enterprise. He won the game and a kiss. (TOS comic: "The Hijacked Planet")