One person is chosen (by a predetermined method, e.g., coin flip, win or loss of previous game, or lag) to shoot first and break the object ball rack apart. If the shooter who breaks fails to make a legal break , then the opponent can call for a re rack and become the breaker, or elect to play from the current position of the balls.
Long exposure photograph of a break in eight ball
According to World Standardized Rules, if the 8 ball is pocketed on the break without fouling, the breaker may ask for a re rack and break again, or have the 8 ball spotted and continue shooting with the balls as they like. If the breaker scratches while pocketing the 8 ball on the break, the incoming player may call for a re rack and break, or have the 8 ball spotted and begin shooting with ball in hand behind the head string, with the balls as they lie.