Football is a team sport where two teams of eleven players compete against each other to score points by moving the ball into a goal area or over a line. The game is played with a ball that can be kicked or carried and the teams must wear protective equipment including shin guards.
The aim of the game is to score more goals than your opponent in a match which has a playing time of 90 minutes. This is split into two halves of 45 minutes each with a 15 minute break called half time. Any player who is deemed to have committed a serious foul may be sent off, this will depend on the referees discretion. A player could receive either a yellow or red card, the latter resulting in their dismissal from the game.
A runner is considered out of bounds if any part of their body other than their hands or feet touches the ground, any part of the end zone structure or any touchline. Runners may also be ruled out if they touch any object on or off the sidelines, this includes the defending players and officials. In the event that a runner is caught with their arm in the air, this is considered a penalty as the ball must be dropped and returned by another defender.
When the ball is in play it is in possession of the offensive team who are given four attempts to advance the ball at least 10 yards downfield. Upon failing to do so the ball is turned over to the opposing defensive team.
There are strict rules on how the offensive team must line up before each play. A quarterback, known as the QB, runs the offense and tries to pass or hand off the ball to runners in order to gain yards downfield. He is protected by a centre, left and right tackle and a left and right guard who protect him from the defenders while he looks for open receivers to pass to.
In addition to these positions there are other players who make up the offense such as a running back, tight end and wide receivers who can catch passes or run the ball for yardage. The smallest players on the offense are known as fullbacks who are used to block and take handoffs from the quarterback and running backs.
Once a team has managed to gain enough yards to reach the end zone they can choose to try and score extra points by kicking the ball through the uprights. Alternatively they can opt for a field goal which is scored by kicking the ball over the crossbar and through the uprights.
In the rare event that a player can knock a ball into the opponents end zone while it is in their possession they will be awarded two points for a safety. However this is very difficult to achieve as the defending team must be in a position to intercept or tackle the ball carrier while he is in their own end zone.