of 10 minutes periods are played (with an interval of 5 minutes in between) if the game is tied after full-time. If scores are level after 100 minutes then the rules call for 20 minutes of sudden-death extra time to be played. If the sudden-death extra time period results in no scoring a kicking competition is used to determine the winner. However, no match in the history of the Rugby World Cup has ever gone past 100 minutes into a sudden-death extra time period. Passing and kicking Forward passing (throwing the ball ahead to another player) is not allowed; the ball can be passed laterally or backwards. The ball tends to be moved forward in three ways—by kicking, by a player running with it or within a scrum or maul. Only the player with the ball may be tackled or rucked. A "knock-on" is committed when a player knocks the ball forward, and play is restarted with a scrum. Any player may kick the ball forward in an attempt to gain territory. When a player anywhere in the playing area kicks indirectly into touch so that the ball first bounces in the field of play, the throw-in is taken where the ball went into touch. If the player kicks directly into touch (i.e. without bouncing in-field first) from within one's own line, the lineout is taken by the opposition where the ball went into touch, but if the ball is kicked into touch directly by a player outside the line, the lineout is taken level to where the kick was taken. Breakdowns The aim of the defending side is to stop the player with the ball, either by bringing them to ground (a tackle, which is frequently followed by a ruck) or by contesting for possession with the ball-carrier on their feet (a maul). Such a circumstance is called a breakdown and each is governed by a specific law. Tackling A player may tackle an opposing player who has the ball by holding them while bringing them to ground. Tacklers cannot tackle above the shoulder (the neck and head are out of bounds), and the tackler has to attempt to wrap their arms around the player being tackled to complete the tackle. It is illegal to push, shoulder-charge, or to trip a player using feet or legs, but hands may be used (this being referred to as a tap-tackle or