American football is played by two teams on a 100-yard-long field. The team with possession of the ball is the offense, and they attempt to move the ball down the field by running or throwing it. The defense attempts to take the ball away from the offense to gain possession.
Most football games are 60 minutes, divided into quarters. At the beginning of the first quarter, one team kicks the ball to the end zone of the other team, where a player catches it and returns the ball as far as possible. The third quarter begins with the receiving team from the first quarter kicking off to the other team. The offense has four plays to gain at least 10 yards. Each time they do, they are given another four plays to gain at least 10 yards. If they don't, possession switches to the opposing team's offense.
The goal of the offense is to make it down the entire field and get a player with the ball into the end zone, which is called a touchdown. The offense is allowed to kick the ball away if they can't get a first down, or they can have their kicker attempt a field goal. If the kicker gets the ball through the cross bars in the opponent's end zone, it is worth three points. Touchdowns are worth six points.
After each touchdown, the offense gets the ball at the opponent's 2-yard line for a play. They earn two points if they can run or pass the ball into the end zone, or they can have their kicker attempt an extra point, which is like a field goal but worth one point.