In American Football, the players are divided into four positions: quarterback, running back, and wide receiver. The quarterback is a big and strong player with good hands who directs plays by calling out signals. A quarterback may run with the ball, hand it off to a running back, or pass the ball to a receiver. The quarterback must be a good passer, see the field well, and be able to quickly cut toward openings in the defense. Running backs also play a vital role in the game, blocking for the receiver and the quarterback.
To score a touchdown, the offensive team must cross the goal line. A kicker may attempt a field goal in some cases, but most of the time, this is a last resort. A team can also attempt a safety on fourth down when an opponent steps out of bounds in its own endzone. The game is divided into four quarters, with a halftime break during the second and third quarters. The offensive team will try to score a touchdown by crossing the goal line, but a safety is scored when an opponent travels backwards into his own endzone, is tackled, or steps out of bounds.
There are 17 laws in football. Each has specific rules. There are also referees who control the game. They are also the timekeepers. Two assistant referees patrol the touchlines, signaling when the ball is out of play and when players are offside. Football laws are governed by a referee and IFAB. The official FIFA website offers the full set of laws. These laws are the basis for most of the rules in football.