The ball must be thrown from behind and over the head, using both hands. This motion is sometimes difficult for young players to master, and referees in younger divisions may, at their discretion, allow retakes in order to help the players learn this skill. Unlike basketball and gridiron football, the boundary lines are part of the field of play. The ball is not out of play until it has completely crossed the goal line or touch line. This implies that a goal is not scored unless the ball has wholly crossed the goal line between the goal posts and beneath the crossbar.
Soccer is a sport designed to give skill the advantage over force.
The Laws permit physical contact, but limit it to non-dangerous forms. Other kinds of contact are illegal and are penalized by the referee. Careless, reckless, or unnecessarily hard contact by a player on his opponent does not become legal simply because the ball was struck in the process. Referees penalize only clear infringements. In fact, they are specifically instructed not to penalize doubtful or trifling breaches of the Laws.