Football is a game in which players try to advance the ball down the field by running with it or throwing it to teammates. Teams compete to score points by either running the ball into their opponent’s end zone (a touchdown worth six points) or kicking the ball through the end-zone structure called goal posts for three points (a field goal). Players on the losing team can also try to take the ball away from the opposing team by tackling them.
The game begins with a coin toss to determine which team will kick off first. From there, each team gets four chances, or downs, to move the ball 10 yards forward. If they do not make it 10 yards in that time, the other team regains possession of the ball (unless a player recovers a dropped or intercepted pass, which is a turnover).
On each play, a center snaps the ball to the quarterback, who then hands off to running backs for yardage gains or throws to receivers for touchdowns. The quarterback can only be tackled behind the line of scrimmage or by players on the defensive side of the field. A player is deemed out of bounds if any part of his body, including his feet, touches the ground or any other object on the sidelines or end lines.
Special teams, such as the kick returner and punt returner, help each team move the ball. The long snapper, who positions the ball for the center, is also an important member of the offensive line. These players, along with the guards and tackles, block for the quarterback and help protect runners from being hit by opposing defenders.
A team of officials on the sidelines handles a chain-link fence that marks the line of scrimmage. On each end of the field are two 10-yard-wide areas, called the end zones. A 6-foot-wide boundary line, called the end line, connects these end zones and runs parallel to the sides of the field. Two pylons flank the end of each end zone.
On each play, the offense tries to gain 10 yards or more. The officials keep track of the yards gained or lost during each down and the number of times a team makes it to 10 yards or more. If the offense fails to make it in that time, the other team takes over with the ball (unless a team recovers a fumble or intercepts a pass).