American football can look chaotic at first: 22 players, frequent stops, flags on the field. Once you understand downs, scoring and the clock, the game becomes a strategic contest you can follow play by play.
The field and the teams
Each team has 11 players on the field. The field is 100 yards long between the goal lines, with a 10-yard end zone at each end, and 53⅓ yards wide. Teams have separate units for offense, defense and special teams (kicks and punts).
Downs and distance
The offense has four attempts, called downs, to advance the ball 10 yards. If it succeeds, it earns a new set of four downs (a first down). If not, the ball goes to the other team. On fourth down, most teams punt or try a field goal rather than risk giving the ball away close to their own end zone. When a commentator says “third and 4”, it means the third down with 4 yards still needed.
Scoring
- Touchdown: 6 points, carrying or catching the ball in the opponent’s end zone.
- Extra point: 1 point for a kick after a touchdown, or 2 points for a successful play from close range (the two-point conversion).
- Field goal: 3 points, kicking the ball through the uprights.
- Safety: 2 points for the defense when the ball carrier is tackled in their own end zone.
The clock
NFL and college games have four 15-minute quarters; high school games usually have 12-minute quarters. The clock stops after incomplete passes, when a player runs out of bounds (in some situations), after scores and for timeouts. Between plays, a play clock (40 seconds in most NFL situations) limits how long the offense can take.
Officials and fair play
A crew of officials watches different areas: the line of scrimmage, the backfield, deep passes. They throw a yellow flag for penalties, which cost the offending team yards. Many rules exist to keep competition fair, such as limits on holding and interference, and others to protect players, such as bans on hits to the head or on defenseless players. Replay review adds a second check on key calls; see how instant replay works.
The full NFL rulebook is published on NFL Football Operations. For the flags you will see most often, read common penalties explained, and for who does what, the positions in American football.
