Billiard ball
(重定向自Cueball)

![A standard set of carom billiards balls (61.5 mm [2 7⁄16 in] diameter), including a red object ball, a plain white cue ball, and a dotted cue ball for the opponent. Some games use an additional object ball.](/uploads/202501/07/Carom_billiards_balls1420.jpg)


A billiard ball is a small, hard ball used in cue sports, such as carom billiards, pool, and snooker. The number, type, diameter, color, and pattern of the balls differ depending upon the specific game being played. Various particular ball properties such as hardness, friction coefficient and resilience are important to accuracy.