What is American Rotation?
Here’s a good video explanation of American Rotation rules.
American Rotation is a 15-ball game developed by Joe Tucker similar to 9-ball and 10-ball, but with slightly different rules. Instead of the game being won by pocketing the highest numbered ball, it is a points game where each ball pocketed earns a player points. Balls 1 through 10 are worth 1 point each and balls 11 through 15 are worth 2 points each. The game is played to a pre-set number of points (e.g., 150). The first person to reach the target number of points wins the game. Like all rotation games, the lowest-numbered ball on the table must always be struck first, and you continue shooting after pocketing a ball with a legal shot. Unlike 9-ball, slop doesn’t count. All shots must be called (unless they are obvious). If a shot is missed, the opponent has the option to shoot or have the current shooter remain at the table (e.g., if the cue ball is left in a bad place after a missed shot). If you don’t want to attempt to pocket a ball, you also have to option to call and play a safety.
The first break is decided by a lag shot. A full rack of 15 balls is used on every break. After the first break, there is an option to shoot, play safe, or push out as in 9-ball. After every subsequent break, the shooter takes ball in hand after the break. Whoever pockets the last ball on the table breaks another full rack of 15 balls with ball-in-hand behind the head string. This continues until a player reaches the target number of total points.
In the event that your opponent fouls on three consecutive shots, you get a free shot (i.e., if you miss, you get an extra turn before your opponent returns to the table). This free shot only applies to the current rack (i.e., it doesn’t carry over to the next rack of balls).
Note – A related drill and rating system based on 15-ball can be found here: 15-ball-rotation rating drill.