Table tennis, also known as ping pong, is a sport in which two or four players hit a lightweight, hollow ball back and forth to each other with rackets (also known as 'bats' or 'paddles'). The game takes place on a hard table divided by a net. Players must allow a ball played towards them only one bounce on their side of the table and must return it so that it bounces on the opposite side. Points are scored when a player fails to return the ball within the rules. Play is fast and demands quick reactions. A skilled player can impart several varieties of spin to the ball, altering its trajectory and limiting an opponent's options to great advantage.