American Football (NFL) — Official Rules

American football is played by two teams of eleven (11) players each on the field at one time. One team has possession of the ball (the offense) and attempts to advance it toward the opponents' end zone to score; the other team (the defense) tries to stop that advance and gain possession. Play proceeds as a series of short plays (downs) that begin with a snap or a free kick. The team that scores the greater number of points at the end of playing time is the winner.

Each NFL game is controlled by a crew of seven (7) on-field officials: the Referee (crew chief, responsible for the spot of the ball and final rulings), Umpire, Down Judge, Line Judge, Field Judge, Side Judge and Back Judge. They are supported by the Replay Official in the stadium booth and the NFL Officiating department in New York, which assists on replay reviews. Officials enforce the rules, signal scores and fouls, and manage the game and play clocks.

The playing field is a rectangle 360 feet (120 yards) long and 160 feet (53⅓ yards) wide. The field of play between the two goal lines is 100 yards long, and each end zone is 10 yards deep. The field is marked with yard lines every 5 yards and with hash marks (inbounds lines) located 70 feet 9 inches in from each sideline; the ball is spotted between or on the hash marks.

A single goal post stands at the back of each end zone. The crossbar is 10 feet (3.05 m) high, the uprights are 18 feet 6 inches (5.64 m) apart, and they extend at least 35 feet above the crossbar. A field goal or extra-point kick counts only when the ball passes above the crossbar and between the uprights. The official ball is a prolate spheroid of pebbled leather, 11 to 11¼ inches long with a long-axis circumference of about 28 to 28½ inches, inflated to 12.5–13.5 psi.

A touchdown (worth six (6) points) is scored when any part of the ball, legally in possession of a player who is inbounds, breaks the plane of the opponents' goal line, or when a player legally recovers or catches the ball in the opponents' end zone. A touchdown can result from a run, a forward pass caught in the end zone, a fumble or interception returned for a score, or a kick/blocked-kick recovery. After a touchdown the scoring team attempts a try (see Article 3.2).

After a touchdown the scoring team is awarded one untimed down, the Try, to add points. It may attempt:

• A place-kick (extra point / PAT) for one (1) point, snapped from the opponents' 15-yard line, that must pass through the goal; or
• A two-point conversion for two (2) points, snapped from the 2-yard line, by running or passing the ball across the goal line. If the defense returns a blocked kick, fumble or interception the length of the field on a Try, it scores two (2) points.

A field goal (worth three (3) points) is scored when a place-kick or drop-kick, taken from scrimmage, sends the ball above the crossbar and between the uprights before it touches the ground or a player of the kicking team. A field goal is most often attempted on fourth down. If a field-goal attempt is missed (no_good or blocked), the defense takes possession at the spot of the kick (or the 20-yard line if the spot is inside the 20).

A safety (worth two (2) points for the defense) is scored when the ball becomes dead in possession of a team in its own end zone, provided the impetus that put the ball there came from that same team — for example, when a ball-carrier is tackled in his own end zone, or commits a foul there. After a safety, the team that was scored upon must put the ball in play with a free kick (a punt, place-kick or drop-kick) from its own 20-yard line.

A regulation game consists of four (4) quarters of fifteen (15) minutes each, divided into two halves. After the second quarter there is a halftime intermission of 13 minutes (longer for special events). Teams change ends at the start of the second and fourth quarters. The game clock starts and stops according to the rules (it stops on incomplete passes, when a runner goes out of bounds, after a score, on timeouts and at the two-minute warning).

The two-minute warning is an automatic charged timeout that the officials call when the game clock reaches 2:00 in the second and fourth quarters. It does not count against either team's timeouts. After the two-minute warning, coach's challenges are no longer permitted; all reviews in the final two minutes of a half are initiated by the Replay Official (booth review), not by the coaches.

Between plays the offense must put the ball in play within the play clock. The standard play clock is 40 seconds, started when the previous play is whistled dead. A 25-second play clock is used after certain administrative stoppages (penalty enforcement, charged timeouts, the two-minute warning, change of possession, measurements, etc.). Failure to snap the ball before the play clock expires is a delay of game foul (5-yard penalty).

If the score is tied at the end of regulation in a regular-season game, a single 10-minute overtime period is played after a coin toss. Both teams are guaranteed an opportunity to possess the ball — even if the team with the first possession scores a touchdown, the opponent still receives a possession (sudden death applies only thereafter). Each team has two (2) timeouts. If the score is still tied at the end of the 10 minutes, the game ends in a tie.

In the postseason (playoffs) a game cannot end in a tie. Overtime is played in 15-minute periods, and as many periods as necessary are played until a winner is determined. Both teams are guaranteed a possession in the first overtime period; thereafter the next score wins. A 2-minute intermission separates overtime periods, and teams change ends between them.

The offense is given a series of four (4) downs (plays) in which to advance the ball at least ten (10) yards. If it gains the necessary yardage, it is awarded a new first down and a fresh series of four downs. If it fails to gain 10 yards in four downs, the ball is turned over on downs to the opponents at the spot where the ball is declared dead. Each play begins with a snap and ends when the ball is dead.

Possession changes to the opponents on a turnover. The main types are:

• Interception – a defender catches a forward pass.
• Fumble – a player loses the ball before being down and the opponents recover it.
• Turnover on downs – the offense fails to gain a first down in four plays. A turnover may be returned for a touchdown. After a change of possession, the new offense starts a fresh series with a first down and ten yards to go.

The game and each half begin with a kickoff, now played under the Dynamic Kickoff format (introduced in 2024 and made permanent in 2025). The kicker kicks from the 35-yard line, while most coverage and return players are aligned in a tight setup zone to make returns safer and more frequent. A touchback — a kick that reaches the end zone and is not returned — is spotted at the 35-yard line. New for 2026: to remove the incentive to kick out of bounds, a touchback on a kick made from the 50-yard line is spotted at the 20-yard line instead.

An onside kick is a short kickoff that the kicking team tries to recover to retain possession. The kicking team must declare its intent so the special alignment can be set. Changed in 2025: a trailing team may now declare an onside kick at any point in the game, not only in the fourth quarter as before; coverage players may line up one yard closer to improve the recovery rate. Refined for 2026: the onside-kick declaration rule and kickoff alignment were further adjusted (the receiving team needs five players, rather than six, with a foot on the restraining line).

A punt is a kick — usually on fourth down — in which the punter drops the ball and kicks it before it touches the ground, in order to give the opponents poorer field position. Possession passes to the receiving team, which may attempt a return, signal a fair catch (no advance, no contact), or let the ball go for a touchback (downed in the end zone). A blocked punt remains a live ball and may be recovered and advanced by either team.

A foul is a rules violation that carries a yardage penalty, marked by an official's flag. Penalties are graded by severity:

• 5 yards – e.g. offside, false start, delay of game, encroachment, illegal formation.
• 10 yards – e.g. offensive holding, illegal block in the back.
• 15 yards – e.g. personal fouls, roughing the passer/kicker, face mask, unsportsmanlike conduct. The non-offending team may accept or decline the penalty. Offsetting fouls (one on each team) cancel each other and the down is replayed. A defensive foul that gives the offense the necessary yardage, or many personal fouls, results in an automatic first down.

Defensive pass interference (DPI) — illegally restricting an eligible receiver's opportunity to catch a pass — is a spot foul: the ball is placed at the spot of the foul and the offense gets an automatic first down (if the foul occurs in the end zone, the ball is placed at the 1-yard line). Offensive pass interference is a 10-yard penalty from the previous spot. Disqualification: a player who commits a flagrant personal foul or non-football act may be ejected from the game; for 2026, league personnel may consult with field officials on such disqualifications even without an initial on-field call.

Each team is allowed three (3) charged timeouts per half (three in the first half and three in the second). Unused first-half timeouts do not carry over to the second half. A charged timeout normally lasts up to two (2) minutes. In regular-season overtime each team has two (2) timeouts. A team that has used all its timeouts cannot stop the clock and cannot initiate a coach's challenge.

American football uses unlimited free substitution: teams routinely change entire offensive, defensive and special-teams units between plays while the ball is dead. No more than eleven (11) players of a team may be on the field at the snap; too many men on the field is a 5-yard penalty. When a player is injured and the clock is running, the officials may call an injury timeout to stop play; the injured player must then leave for at least one play.

Outside the final two minutes of each half, a head coach may challenge a reviewable on-field ruling by throwing a red flag. Each team is allowed two (2) challenges per game and is granted a third challenge if at least one of its first two is successful (changed in 2024). A challenge may be made only when the team has at least one timeout remaining: if the challenge fails, the team is charged a timeout; if it succeeds, the ruling is overturned and no timeout is lost.

In the final two minutes of each half, in overtime, and on all scoring plays and turnovers, replay reviews are initiated by the Replay Official in the booth rather than by a challenge. A centralized Replay Assist system (NFL Officiating, New York) can help on-field officials correct certain clear and obvious errors quickly. New for 2026 (one year only): if a referee work stoppage occurs, the NFL Officiating department is authorized to correct clear and obvious mistakes by on-field officials that impact the game.

Recent structural changes carried into 2026:

• Dynamic Kickoff (2024) made permanent in 2025, with the touchback spotted at the 35-yard line.
• Overtime alignment (2025): the regular-season and postseason both-possession rule now guarantees each team a possession; regular-season OT is 10 minutes and can end in a tie.
• Expanded replay assist and Hawk-Eye optical tracking adopted to aid measurements and reviews.
• The "tush push" (quarterback push play) remains legal — no ban was adopted.

Approved at the March 2026 Annual League Meeting (effective for the 2026 season):

• Onside kick may be declared at any time during play (kicking-team flexibility).
• Out-of-bounds kickoff incentive removed: a touchback on a kick from the 50-yard line is spotted at the 20-yard line.
• Kickoff alignment for the receiving team modified (five players on the line instead of six).
• Disqualification review: league personnel may consult with field officials on flagrant or non-football-act disqualifications.
• Emergency replay authority (one year only): NFL Officiating may correct clear and obvious on-field mistakes during a referee work stoppage.