How to play American Football

The fundamental thing in american football is to score most points by taking the ball into the oponents endzone or by kicking the ball between the goalposts. Every team has up to 45 players each, with 11 on the field at the same time. Every player has his own specific position and the team has offensive and defensive players. All team have its own "playbook" with a numeric amount of plays to fool the opponents defence and get as much yardige as possible.
The field

The field is about 109 meters(100 yards) long and 49 meters wide. It is divided between the endzones with parallel lines(yardlines) every 10:th yard (10 yards=9,14 meter). Behind the goalline is the endzone.

The game
American football is a game of positions. The offensive team has 4 atempts to advance 10 yards. When a team reach that limit, it gets 4 new atempts to reach 10 yards and so on until the goalline is crossed. Then the team is awarded 6 points and gets a chance to score an extrapoint.
Positions

C.......Center RB.....Runningback G.......Guard DT.....Defensive Tackle T.......Tackle DE.....Defensive End QB......Quarterback LB.....Linebacker WR......Widereceiver CB.....Cornerback TE......Tightend S......Safety K.......Kicker P......Punter

Downs
During the atempt(downs), the players in both teams gather up in formations on each side of the ball. A down starts when the center in the offensive team lifts the ball off the ground. The ball can be carried, thrown or handed to another player. The down starts with a call from the QB, the center lifts the ball and gives it between his legs to the QB(snap). Before the down the players have been deciding what particular play they want to run. When the ballcarrier gets tackled or runs out of bounds the play stops and the next play starts from that spot. There are a lots and lots of diffrent plays but every single play falls into three difrent categories run, pass or kicking plays.

During a run-play the QB give the ball to player that is supposed to be the ballcarrier for this play, most likely a runningback or fullback. His teamates tries to block a gap for him to get through.

When a pass-play is called the QB throws the ball to an elligable reciver downfield. The supposed reciever runs a pre-decided pass-pattern to get away from his defender and catch the ball. The recivers, ends and backs are the only offensive players who are allowd to go beyond the scrimageline before the ball is thrown.

A kicking-play is most likely decided on the fourth down when the QB isn´t sure to get first down. The center throws the ball between his legs to the punter who has lined up about 15-20 yards behind him. The punter tries to kick the ball as high and long as possible and the defensive team lines up with a single player in the backfield to catch te ball and return it as far as possible. The offensive players has to stop the return by hitting the returner as soon as possible, there for the kick has to have a lot of air-time. The spot where the returner is hit makes the starting spot for his offence to advance forward. If the offensive team is close enough to kick the ball between the goalposts, a player lines up on his knees 10 yards behind the center and places the ball on the ground. When the ball is in place the kicker tries to score by kicking the ball as hard as he is able. If the ball is kicked with accuracy and skill it´s between the goalposts and the team is rewarded 3 points.

Game-time
A game is played in four quarters. A quarter is 12 minutes efficient time. The clock stops when a passing-attempt isn´t completed, a ballcarrier runs out of bounds or when a penalty is decided.

Fumble
If a ballcarrier has control over the ball and drops it makes a fumble. The ball i now free to pick up for any player. The team who picks the ball up has possession of the ball under the next play.

Interception
When the defensive team successfully catches the ball while the ball is in the air they are changing possession of the ball.

Violations
Even though american football is a contact-sport the players has to follow certain rules. A player isn´t allowed to fist-hit, kick, knee or tackle an opponent when the whistle is blown. A serious violation is to pull the facemask.
Penalties
The penalties are often not personal but of serious importance to the team. There are no such things as yellow cards or 2 minute-penalties(as in hockey). The penalties in american football is mostly loss of yardige or loss of down. Players can be ejectet but that isn´t common.

Points
Touchdown - 6p. An offensive player recieves the ball inside the defensive endzone or carries it in. When touchdown is awarded the team also get an opportunity to score an extrapoint.
Extrapoint - 1p. When a fieldgoal is kicked directly after a touchdown.
Extrapoint - 2p. When the ball is thown or carried into the endzone again dirctly after a touchdown. Fieldgoal - 3p. When a kicker kicks the ball between the goalposts.
Safety - 2p. When the defensive team stops a ballcarrier inside their enzone (reversed touchdown).