Yotsudama is a form of four-ball billiards that is played in Japan. In this form, the four billiard balls used are, two red object balls, one white cue ball, and one yellow cue ball. Sometimes games are also played with a second white cue ball with a visible red dot.
Each player assigned to use one cue ball. In Yotsudama the opponent’s cue ball can also be used as an object ball. Points are scored when a player's cue ball caroms off of two balls in a single shot. If the cue ball caroms off only a single ball, no points are awarded, and the player ends up losing their turn.
Before the start, both red balls are placed at the opposing ends in the middle of the table. The two cue balls are each placed behind one red ball. The first player to start should hit the red object ball closest to their cue ball and one or both the other balls. Players continue to take turns to score points.
Striking two red balls scores three points and striking one red and the other cue ball scores two points. The game is played till one player reaches a score that was agreed upon before the start of the game.
- Four-Ball — a Carom Billiards discipline, played on a pocketless table with four balls (2 red, 2 white), where a point is scored when a player caroms on any two other balls, and two points are scored when the player caroms on each of the three other balls.
- Carom Billiards — A cue sport played on a felt-covered table with cues and billiard balls, in which the object is to score points by caroming your cue ball off both the opponent's cue ball and the object ball(s) with a single shot.