The aim of American football is to score more points than your opponent. Points are scored by taking the football into the opponent's end zone or by kicking a field goal. The main objective is to gain space (offense) and defend your own territory (defense).
A game lasts 4×12 minutes, which is the net playing time. In contrast to soccer, there is no stoppage time; the clock is stopped during interruptions. The sides are changed after the first and third quarters, and there is a 15-minute half-time break after the second quarter. The field is 100 yards long and 53.3 yards wide, which is approximately 91.4 x 48.7 meters.
The game starts with a coin toss to decide who gets the ball first. The defending team starts with a kick-off from their own 35-yard line. The offense must catch the ball and carry it as far as possible in the other direction. The defense tries to prevent this. The offense has four attempts (downs) to gain at least 10 yards. If they succeed, they receives four new downs.
Touchdown (6 points): The ball is carried or thrown into the opponent's end zone.
Extra point (1 point): After a touchdown, the ball is kicked through the goal posts.
Two-point conversion (2 points): Instead of an extra point, another attempt is made to get the ball into the end zone.
Field goal (3 points): The ball is kicked through the goal posts during one of the four downs.
Safety (2 points): The defense scores points when it stops the attacking player in their own end zone.
Quarterback (QB): The playmaker who throws the ball or hands it off to running backs.
Wide Receiver (WR): Catches passes and runs toward the end zone.
Running Back (RB): Carries the ball and tries to get through the defense.
Fullback (FB): Blocks for the running back, also takes on short runs.
Tight end (TE): Hybrid position that can both catch and block.
Offensive Line (OL): Protects the quarterback and blocks for the ball carrier.
Center (C): Passes the ball to the quarterback by taking a snap.
Defensive Tackle (DT): Pressures the quarterback and stops the run.
Defensive End (DE): Attacks the quarterback and stops the run.
Linebacker (LB): Defends against the run and pass, sometimes attacking the quarterback.
Cornerback (CB): Defends against passes to the wide receivers.
Safeties (S): Last line of defense against passes and runs.