The quarterback is the most important person on the field in the game of football.
The quarterback directs his team’s offense, therefore controlling the flow of the game. The defense's job is to keep him and his teammates from scoring. It all revolves around the quarterback.
The offense's job is to score points for the team. This happens through a series of predetermined, practiced routines called plays.
The quarterback is the player who calls out what plays will be run; he is sometimes referred to as the "signal caller." The quarterback's position can be compared to a field general in the military. He is the on-field boss. He receives the play information from the from the offensive coordinator, but at the last minute can call an "audible" and change what play will be run.
The objective of a play is to move the football closer to the opponent's goal, also known as the end zone. The quarterback can start the move toward the end zone by throwing the ball, handing it off or running with it himself.
The offense has four "downs," or tries, to move the ball 10 yards. When the ball has been moved the required 10 yards or more, it is considered a "first down." The quarterback can pass or run the ball to make a first down.
After the first down is made, the offense is then given four more downs to attempt to get another first down. This continues until an offensive player scores, or until the offense cannot get a first down in four tries. When this happens, the special teams unit will "punt" the ball, kicking it back to the opposing team.
The offense scores by entering the opposing team's end zone with the ball. Once the player with the ball breaks the plane of the goal line that separates the field from the end zone, a touchdown is scored. A touchdown is worth six points.
After a touchdown, the offensive team has the opportunity to kick the ball through the goal posts for an extra point or go for the two-point conversion. You can recognize the two-point conversion attempt by the way the teams line up - it will look like they are trying to score another touchdown.
If the offensive team is close to the end zone but gets into a situation where a first down attempt is not likely to succeed, a kicker may be brought onto the field for a field goal attempt. Usually the offense has to be on the same side of the field as the opponent's end zone for this to happen, but a field goal can be attempted from any distance. The kicker must put the ball between the uprights of the goal posts and above the crossbar for the field goal to count. A field goal is worth three points.
