The form of the game played in pocket billiard championships is called 14.1 continuous. In this game, 15 object balls, numbered from 1 to 15, are used. These are placed on the table in triangle formation (a triangular wooden form is used for collecting, or racking, the balls), with the apex on the foot spot and the triangle base parallel to the foot rail. The object is to complete 150 points, one point being awarded for each ball pocketed. This is a call-shot game; that is, the player announces the ball and pocket he intends to play.
The starting player on the opening, or break, shot must drive two or more object balls to a cushion or cause an object ball to drop into a pocket. This constitutes a legal break. The opponent then takes over and tries to pocket all the balls except one. This is called the break ball, which must remain on the table until the pocketed balls are reracked and set in position, with the apex vacant, again at the foot spot. The player then tries to pocket the break ball and carom the cue ball from the break ball into the racked balls. He continues scoring the 14 balls, having them reracked, and breaking until he misses, scratches, or scores the winning point.
In rotation the 15 object balls are racked so that the 1-ball is at the apex and placed on the foot spot, the 2-ball is at the left angle of the rack, and the 3-ball at the right. Players must pocket the object balls in numerical order, beginning with the 1-ball. Points are awarded according to the number of the balls, and the player who first reaches 61 points wins.
In eight ball the object balls are racked so that the 8-ball is in the center. One player uses balls numbered from 1 to 7; the other, 9 to 15. The first to pocket his allotment, and then pocket the 8-ball, wins.
The game of American snooker uses 21 object balls. Fifteen are red balls without numbers and score one point each when pocketed; six are colored balls with numbers and score the value of the ball (black, 7; pink, 6; blue, 5; brown, 4; green, 3; yellow, 2). The red balls are racked so that the apex ball is on the foot spot; the numbered balls are spotted according to a designated pattern on the table.
At the start, the first ball to be pocketed must be a red one. As play continues, players alternate between a red and a numbered ball, calling each shot. The numbered balls, however, must be respotted after each pocketing, as long as a red ball remains on the table. Once all red balls are pocketed, the numbered balls must be played in numerical order, from 2 to 7. The winner is the player with the highest score.
The most popular of the carom games is three-cushion billiards. This game uses three balls: two object balls (red and white) and a cue ball (white, with a black dot). The red ball is placed on the foot spot on the table; the white ball, on the head spot; and the cue ball, on the head string and six inches to the right or left of the white ball.
To begin play, the first player drives his cue ball against the red object ball. Thereafter, in attempts to score a carom (one point), players may strike either the red or the white ball first. In any case, the cue ball must contact at least three cushions before it hits the second object ball. No cushion contact or a number of contacts may be made by the cue ball before it hits the first object ball. The first player to score 50 points wins the game.
In straight-rail billiards the cue ball must hit the two object balls in succession, with or without cushion contact. The player who reaches a predetermined number of points first wins.