How Does Football Work? American Football Basics Explained

American football is a game of territory. Each team tries to move the ball down the field into the opponent's end zone, a few yards at a time, while the other team tries to stop it.

The field

The field is 100 yards long between the goal lines, with a 10-yard end zone at each end. Yard lines are marked every 5 yards and numbered every 10.

Downs: the core idea

• The offense has four downs (plays) to gain 10 yards.
• Gain 10 yards and you earn a new set of four downs, a first down.
• Fail, and the ball goes to the other team. That is why teams often punt on fourth down, kicking the ball away to push the opponent back.

"Second and 7" means it is the second down with 7 yards still to go.

Scoring

How	Points
Touchdown: ball carried or caught in the end zone	6
Extra point kick after a touchdown	1
Two-point conversion after a touchdown	2
Field goal: kicked through the uprights	3
Safety: ball carrier tackled in his own end zone	2

The three units

• Offense moves the ball by running or passing.
• Defense tries to stop it and take the ball away (interceptions, fumbles).
• Special teams handle kickoffs, punts and field goals.

Who does what: football positions explained.

Game length

NFL and college games have four 15-minute quarters, but the clock stops often, so games last around three hours. Ties after regulation go to overtime; college rules differ from the NFL's, see college football overtime.

Penalties

Officials throw a yellow flag for fouls such as holding, false starts or pass interference. Most penalties move the ball 5, 10 or 15 yards.