American Football Rules — The Short, Honest Version
Football looks complicated because the broadcasts assume you already know the rules. The actual rule set is small. Once you understand the clock, the downs, and how scoring works, ninety percent of any given game makes sense. The other ten percent is penalties and edge cases — covered below.
The shape of a game
Two teams of eleven take turns trying to advance an oval ball into the opposing end zone. The team with the ball is the offense; the other side is the defense. After every score, and at the start of each half, the ball is kicked off and possession is established by the receiving team. Games are sixty minutes of official clock divided into four quarters with a long break at halftime.
Downs: the heart of the rule set
The offense gets four attempts — four downs — to gain ten yards. Make those ten yards and the count starts over. The chains move forward, and you have a fresh first-and-ten. Fail and possession changes.
Every way to score
| Play | Points | How |
|---|---|---|
| Touchdown | 6 | Ball crosses the goal line in possession, or is caught in the end zone. |
| Extra point | 1 | Kick through the uprights from the 15-yard line after a touchdown. |
| Two-point conversion | 2 | Run or pass play from the 2-yard line, after a touchdown, that crosses the goal line. |
| Field goal | 3 | Kick through the uprights at any distance, on any down — usually fourth. |
| Safety | 2 (defense scores) | Offensive ball carrier is tackled in his own end zone, or commits certain penalties there. |
How the clock actually works
The play clock and the game clock are different. The game clock counts down sixty minutes total. The play clock — usually forty seconds — runs between snaps. If the offense doesn't snap before it hits zero, that's a delay-of-game penalty.
The game clock keeps running on most successful run plays and short passes. It stops when:
- A pass falls incomplete.
- A player carries the ball out of bounds.
- A team scores.
- A team calls timeout (each team gets three per half).
- A first down is gained, briefly, while the chains reset.
- The two-minute warning hits at the end of each half.
- A penalty is being enforced or a play is being reviewed.
The seven penalties you will see most often
| Penalty | Yards | What it is |
|---|---|---|
| Holding (offense) | 10 | An offensive lineman grabs a defender to prevent him from rushing. |
| False start | 5 | An offensive player moves before the snap. |
| Offside / encroachment | 5 | A defender crosses the line of scrimmage before the snap. |
| Pass interference (defense) | spot of foul | Significant contact by a defender on a receiver before the ball arrives. |
| Illegal contact / holding (defense) | 5 | Defender holds or contacts a receiver beyond the legal five-yard zone. |
| Roughing the passer | 15 | Hitting the quarterback after the ball is thrown, or hitting him low or high. |
| Unnecessary roughness | 15 | Late hit, helmet-to-helmet, or any flagrant contact. |
The weird stuff: safety, free kick, fair catch
Safety. The defense scores two points if the offensive ball carrier is tackled in his own end zone. The team that gave up the safety then has to free-kick the ball back from their own 20.
Free kick. A free kick is a kickoff-style play used after safeties. The kicking team can choose to punt or place-kick.
Fair catch. A receiver of a punt or kickoff can wave his arm to signal he won't run with the ball after the catch. In exchange, defenders can't tackle him. It's a trade — surrender return yards, gain a clean catch.
Onside kick. A kickoff intentionally squibbed short, hoping the kicking team can recover. Legal if the ball travels at least ten yards before being touched.
FAQ
How long is a football game?
Sixty minutes of game clock split into four fifteen-minute quarters. Real-world length is roughly three hours once you account for stoppages, the two-minute warning, halftime and reviews.
What is a down?
A down is one play. The offense gets four of them to advance the ball ten yards. Get the ten and the count resets to first-and-ten. Fail and the other team takes possession.
Why do teams punt on fourth down?
Because giving the opposing offense a short field is usually a worse outcome than handing them a long one. Punting trades possession for field position. Going for it is a calculated bet that the offense can convert.
How is a touchdown different from a field goal?
A touchdown (six points) is the ball crossing the goal line in possession of an offensive player, or a player catching a pass with both feet down in the end zone. A field goal (three points) is a kick that splits the uprights.
What is pass interference?
Significant contact by a defender on a receiver while the ball is in the air, before the ball arrives, in a way that prevents the catch. The penalty is large because the play is functionally a stolen completion.
Why does the clock sometimes stop and sometimes not?
The clock stops on incomplete passes, on first downs (until the ball is set), when a player goes out of bounds, after a score, on penalties, on timeouts, and during reviews. Otherwise it runs.
What is a two-point conversion?
After a touchdown the offense can choose either an extra-point kick (one point, almost automatic) or a play from the two-yard line worth two points if the offense scores again. The two-pointer is the higher-variance option.
What happens on overtime?
Pro football overtime is fifteen minutes. Both teams get at least one possession unless the team that gets the ball first scores a touchdown, in which case the game ends. If the score is still tied after the period, the regular-season game is a tie; in playoffs they keep playing.