American four-ball billiards

Four-ball billiards (often abbreviated to simply four-ball, and sometimes spelled 4-ball or fourball) is a carom billiards game, played on a pocketless table with four billiard balls, usually two red and two white, one of the latter with a spot to distinguish it (in some sets, one of the white balls is yellow instead of spotted). Each player is assigned one of the white (or yellow) balls as a cue ball. A point is scored when a shooter's cue ball caroms on any two other balls in the same shot (with the opponent's cue ball serving as an object ball, along with the reds, for the shooter). Two points are scored when the shooter caroms on each of the three object balls in a single shot. A carom on only one ball results in no points, and ends the shooter's inning.

A variant of four-ball is the East Asian game yotsudama (四つ球, Japanese for 'four balls'), or sagu (사구, Korean for 'four balls').

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