In American football, two teams of 11 players each try to move the ball down the field and into the opponent’s end zone. The team with the ball, the offense, gets four downs, or plays, to gain 10 yards. If it succeeds, it earns a new set of four downs; if not, the ball goes to the other team. Teams score with touchdowns (6 points), extra points (1 or 2), field goals (3) and safeties (2). Games in the NFL and college are divided into four 15-minute quarters, and officials enforce penalties for fouls such as holding, false starts and pass interference. The team with the most points at the end wins.
The basics
| Element | Rule |
|---|---|
| Players | 11 per side on the field |
| Field | 100 yards between goal lines, plus two 10-yard end zones; 53⅓ yards wide |
| Game length | Four 15-minute quarters in the NFL and college; high school usually 12 minutes |
| Downs | Four attempts to gain 10 yards |
| Objective | Score more points than the opponent |
The field
The field is 120 yards long including the two end zones and 53⅓ yards wide. Yard lines run across the field every 5 yards, numbered every 10 yards from each goal line to the 50-yard line in the middle. Hash marks near the center of the field mark where the ball is placed at the start of each play, and goalposts stand at the back of each end zone. The line of scrimmage is the imaginary line where the ball rests before each play, and neither team may cross it before the snap.
How a game starts and flows
A coin toss decides which team chooses to kick off or receive. The game begins with a kickoff, and the receiving team tries to return the ball as far as possible. From there, the offense runs plays from scrimmage. Each play begins with a snap, when the center passes the ball back between their legs, usually to the quarterback. The offense can run the ball, pass it forward once per play from behind the line of scrimmage, or kick it. A play ends when the ball carrier is tackled, goes out of bounds, scores, or a forward pass falls incomplete. Teams switch ends after each quarter, and halftime follows the second quarter.
Downs and first downs
The offense has four downs to advance the ball 10 yards from where the series began. Reaching or passing that mark earns a first down and a new set of four downs. If the offense fails to gain 10 yards after three downs, it usually punts on fourth down to push the opponent back, attempts a field goal if close enough, or goes for it and risks turning the ball over at that spot. Broadcasts often show the target as a yellow line on screen, while on the field, a chain crew marks the distance with two poles connected by a 10-yard chain.
Scoring
| Score | Points | How it happens |
|---|---|---|
| Touchdown | 6 | Carrying or catching the ball in the opponent’s end zone |
| Extra point kick | 1 | Kicking through the uprights after a touchdown |
| Two-point conversion | 2 | Running or passing into the end zone after a touchdown |
| Field goal | 3 | Kicking the ball through the uprights from scrimmage |
| Safety | 2 | Tackling the ball carrier in their own end zone, among other situations |
After a safety, the team that gave up the points kicks the ball to the other team from its own 20-yard line.
Timing and the clock
The game clock stops for incomplete passes, when a player runs out of bounds, after scores, for penalties and when teams call timeouts. Each team usually has three timeouts per half. A separate play clock limits how long the offense has to start each play; in the NFL it is typically 40 seconds from the end of the previous play, with a shorter 25-second clock after certain stoppages. Rules about when the clock stops and restarts differ between the NFL, college and high school, especially near the end of halves.
Common penalties
| Penalty | What it is | Typical NFL yardage |
|---|---|---|
| False start | Offensive player moves before the snap | 5 yards |
| Offside or encroachment | Defender crosses the line before the snap | 5 yards |
| Offensive holding | Illegally grabbing or restricting a defender | 10 yards |
| Defensive holding | Illegally restricting a receiver or blocker | 5 yards and an automatic first down |
| Pass interference | Illegal contact with a receiver or defender while the pass is in the air | Defensive: ball placed at the spot of the foul |
| Delay of game | Not snapping the ball before the play clock expires | 5 yards |
| Personal foul | Unnecessary roughness, facemask, roughing the passer | 15 yards |
Penalty yardage and enforcement differ between levels. College defensive pass interference, for example, is generally capped at 15 yards rather than being a spot foul.
Overtime
If the score is tied at the end of regulation, overtime rules decide the winner. The NFL, college and high school each use different systems, and the NFL has updated its overtime rules in recent years, including separate procedures for the playoffs. College overtime uses alternating possessions from a set yard line. Because these rules change, check the current rulebook for the level you are watching.
Step by step: how to follow a game
- Watch the down and distance. It tells you what the offense needs, such as third and 5.
- Track field position. Teams play differently near their own goal line than near the opponent’s.
- Watch for flags. A yellow flag means a penalty has been called.
- Follow the clock. Late in halves, teams manage time with timeouts and sideline passes.
- Listen to the referee’s signals. Referees announce penalties and decisions to the crowd.
Levels of play
The core rules are similar across levels, but details differ. The NFL follows its own rulebook, college football in the United States follows NCAA rules, and most high schools follow rules published by the National Federation of State High School Associations (NFHS). Differences include how many feet a receiver must have in bounds for a catch (two in the NFL, one in college and high school), game length, overtime and clock rules.
Common mistakes beginners make
- Thinking a team gets four downs to score rather than to gain 10 yards.
- Confusing false start (offense) with offside (defense).
- Assuming any forward pass is legal; only one is allowed per play, from behind the line of scrimmage.
- Forgetting that rules differ between the NFL, college and high school.
- Not realizing that a safety also gives the scoring team possession.
Rulebook note: this article summarizes common rules and is not an official rulebook. Rules are updated regularly, so check the current NFL Rulebook, NCAA Football Rules or NFHS Football Rules for the level you play or watch.
Frequently asked questions
How many downs do you get in football?
The offense gets four downs to gain 10 yards and earn a new set of downs.
How long is a football game?
NFL and college games have four 15-minute quarters, although stoppages mean games usually last about three hours.
What is the difference between a field goal and an extra point?
A field goal is worth 3 points and is kicked during a drive, while an extra point is a 1-point kick attempted after a touchdown.
