Note: this article is incomplete. It is in the process of being split off from American football. Please consult that article for any missing information until the move is complete.
Game play in American football consists of a series of individual plays of short duration, outside of which the ball is not in play. Substitutions can be made between plays, which allows for a great deal of specialization as coaches put in players they think are best suited for any particular situation. The game is very tactical and strategic. With 22 players on the field at a time (eleven on each team), each with an assigned task for a given play, complex strategies have arisen for every part of the game.
Object of the game
The object of the game is to advance the ball to the opponent's end zone and thus score points. The team with the most points when time has expired wins.
Duration
Collegiate and professional football games are 60 minutes long, divided into four quarters of 15 minutes each. In high school football, 12 minute quarters are usually played, resulting in a 48 minute game. Separating the second and third quarters is a halftime. Teams change ends of the field after the first and third quarters. If a game is tied at the end of four quarters, overtime is played. Professional overtime periods are 15 minutes in length and are "sudden death", meaning that the team that scores first, by any means, wins. In college and high school football, an overtime procedure ensures that each team has equal opportunity to score.
Methods of scoring
Points can be scored in several ways. Following any score, play is restarted by a free kick (see below).
Field goal (3 points)
A field goal is scored when the ball is kicked between the goal posts behind the opponent's end zone. The ball is snapped or hiked to a place holder, who holds the ball upright on the ground so that it may be kicked. Three points are scored if the ball crosses the plane of the goal between the two upright posts and above the crossbar. If a field goal is missed, the ball is returned to the original line of scrimmage (or, in the NFL, to the spot of the kick), and possession is given to the other team. Optionally, if the ball does not go out of bounds, the other team may catch the kicked ball and attempt to advance it, but this is usually not advantageous.
Touchdown (6 points)
A touchdown, worth six points, is achieved when a player has legal possession of the ball within the opponent's end zone. Scoring a touchdown is the ultimate goal of the offensive team. A touchdown can also be scored by the defense if an intercepted or fumbled ball is taken to the opponent's end zone. After a touchdown, the scoring team is awarded a try (see below).
Safety (2 points)
A safety is an infrequently-occurring score. If a player causes the ball to become dead in his own end zone, two points are awarded to the opposing team. This can happen if a player is either downed or goes out of bounds in the end zone while carrying the ball, or if he fumbles the ball, and it goes out of bounds in the end zone. A safety is also awarded to the defensive team if the offensive team commits a penalty which is enforced in its own end zone. A safety is not awarded if a player intercepts a pass or receives a kick in his own end zone and is downed there. This situation, in which the opponent caused the ball to enter the end zone, is called a touchback; no points are scored, and the team that gained possession of the ball is awarded possession at its own 20-yard line. If the interception or reception occurs outside the end zone, and the player is carried into the end zone by momentum, the ball is placed at the spot of the catch and no safety is awarded.
Try (1 or 2 points)
A try is a single untimed down played immediately after a touchdown is scored, and before the ensuing kickoff. Either one or two extra points may be scored during the try. The ball is spotted at the 2 yard line (NFL) or 3 yard line (college), and the team which scored the touchdown is allowed to run a single play in an attempt to score.
- If the offensive team scores a field goal on the try, it receives one point. This is commonly referred to as an extra point or the point after touchdown (PAT). Because this short, 20-yard field goal kick is nearly always made when attempted, it is the most common score on a try.
- If the offensive team scores a touchdown on the try, it receives two points. This is commonly referred to as a two-point conversion.
- If the defensive team scores a touchdown on the try, for example by intercepting a pass and then running the full length of the field to the other end zone, it receives two points. This is officially recorded as a safety scored by the defense. The NCAA adopted this rule in 1990. This scenario cannot occur under NFL rules; in the NFL, the ball is dead and the try is over immediately when the defense gains possession.
- In the extremely rare event that the offensive team scores a safety (see below) on the try, it receives one point. In college football, this can occur when the defense gains control of the ball and attempts to advance it, then fumbles it out of bounds in its own end zone. In the NFL, since the try ends once the defense gains possession, a safety can only be scored if a defensive player bats a loose (fumbled) ball out of bounds in the end zone.
Free kicks
A free kick is a special play which does not occur from scrimmage. The kicking team begins behind the ball, while the receiving team must remain at least 10 yards downfield before the ball is kicked.
A kickoff is a kind of free kick used to start each half, and also used to restart the game following a field goal or touchdown. At the beginning of a half, the kicking team is determined by coin toss. After a field goal or touchdown, the kicking team is the team which just scored. The kicking team kicks the ball from its own 30-yard line, though that can be affected by any penalties on the preceding play. (Note: the ball is usually kicked from the 35-yard line in college football). The ball must be kicked from the ground, not punted. A tee is used, unless the ball is blown off the tee by winds twice in succession, in which case the ball must be held by a member of the kicking team. The receiving team may recover and attempt to advance the ball at any time after the kick, but the kicking team may not field the ball until it has traveled at least 10 yards. The ball is usually kicked as deep as possible to the receiving team, in order to force the receivers to start far down the field, but sometimes a team will attempt to recover its own short kick, in a play known as an onside kick. If a kickoff goes out of bounds in the end zone, or if it is downed in the end zone, it is ruled a touchback and the receivers are awarded the ball on its own 20-yard line. If a kickoff goes out of bounds before being touched by a player for the receiving team and before entering the end zone, it is a penalty on the kicking team. The ball is spotted at the point where it went out of bounds, or 30 yards from the point of the kick, whichever is closer, and the receiving team takes possession.
A free kick is used to restart the game following a safety. The team that was trapped in its own end zone, therefore conceding two points to the other team, kicks the ball from its own 20-yard line. In this case, the free kick may be either punted or kicked from the ground, but a tee may not be used and the ball may not be held on the ground.
In the NFL, under an infrequently-used rule, a free kick may be taken on the play immediately after any fair catch as a field goal attempt. The ball must be held on the ground by a member of the kicking team; a tee may not be used. If the ball goes between the goal posts, a field goal is scored for the kicking team. This is the only case where a free kick may score a field goal.
Penalties
Some of the more common penalties are listed below. In most cases the offending team will be assessed a penalty of 5, 10 or 15 yards, depending on the infraction. There may also be a loss of down for an offensive penalty against the defense. Conversely, a defensive penalty against the offense may result in an automatic first down. In some cases, the offense will be given the option of declining the penalty and taking the yardage gained on the play. For some infractions by the defense, the penalty is applied in addition to the yardage gained on the play. Most of a number of personal fouls, which involve danger to another player, carry 15-yard penalties; in rare cases, they result in specific players being ejected from the game.
With three exceptions, no penalty may move the ball more than half the distance toward the penalized team's goal line. These exceptions are defensive pass interference (see the discussion of that penalty for more details), intentional grounding, and offensive holding - but in this last case the exception pertains only if the infraction occurs within the offensive team's own end zone, in which case an automatic safety is assessed (intentional grounding from the end zone also carries an automatic safety).
- Note: The neutral zone is the space defined by lines drawn through the ends of the ball parallel to the yard lines when the ball is spotted and ready for play. No player may legally have any part of his body in the neutral zone when the ball is snapped, with the exception of the center.
Penalties against the offense
- False start (5 yards) - any player moving after they have gotten in their set position before the snap in a way that simulates the start of the play (on occasion this is informally referred to as "traveling," because the signal the official makes to identify the penalty is almost exactly the same as the one a basketball referee makes when calling the infraction of traveling, or "walking" with the ball, in that sport)
- Illegal motion (5 yards) - having more than one back in motion at the snap, or a man in motion moving forward at the time of the snap
- Illegal shift (5 yards) - not being set before the snap
- Illegal formation (5 yards) - having fewer than 7 players on the line of scrimmage
- Delay of game (5 yards) - allowing the 40 seconds given to elapse before the snap (this is sometimes intentionally done on a play where the offense is about to punt from relatively advanced field position - and often the defensive team declines the penalty)
- Ineligible receiver downfield (5 yards) - a lineman beyond the neutral zone prior to a forward pass
- This penalty is not imposed if the receiver is behind the line of scrimmage when he receives the pass. This exception has been added to accommodate the screen pass, where a receiver (most often a back, but sometimes a tight end or wide receiver) catches a ball behind the line of scrimmage behind a "screen" of offensive linemen.
- Illegal forward pass (5 yards and loss of down) - thrown from beyond the neutral zone, or a second forward pass on the same play (originally, intentional grounding - see below - was considered a subset of this; they are now treated as separate infractions)
- Holding (10 yards) - illegal use of the hands or arms while blocking; an automatic safety is assessed instead if spot of infraction is within the offensive team's own end zone.
- Offensive pass interference (10 yards) - interfering with a defender attempting to catch a pass
- Intentional grounding - throwing the ball into the ground to avoid being tackled
- NFL penalty: 10 yards or spot of foul, whichever is farther from the original line of scrimmage, and loss of down
- College penalty: Spot of foul and loss of down
- In both NFL and college, intentional grounding from the offensive team's own end zone constitutes an automatic safety unless the defense chooses to decline the penalty, which might only ever happen if the infraction had occurred on a fourth-down play.
- Note that at any level, if the quarterback has moved outside the area between his offensive tackles, there is no penalty for grounding the ball if the quarterback throws the ball past the line of scrimmage. Also, "spiking" the ball into the ground to stop the clock is always legal, as long as the quarterback's primary intention is to stop the clock (or, far less commonly, to prevent the opposing team from making an instant replay challenge concerning the result of the immediately previous play, as no such challenge can be recognized once another play has been run).
- Illegal block in the back (10 yards) - an illegal block from behind and above the waist
- Clipping (15 yards) - an illegal block from behind and below the waist
- Illegal block (15 yards) - usually a "crackback block".
Penalties against the defense
- Offsides (5 yards) - Being across the line of scrimmage before the ball is snapped, or being in the neutral zone when the ball is snapped; unlike offensive players, defensive players are not compelled to come to a set position before the snap, so if a defender jumps across the line but gets back to his side before the snap there is no penalty. The offense can decline the penalty and take the yardage gained on the play - unlike in the case of a false start penalty against the offense, whereupon the play will be immediately aborted by the officials.
- Encroachment (5 yards) - A defensive "false start," often before the ball is snapped (sometimes regarded as a subset of "offsides" above; indeed, the same referee's signal is used to denote both of these penalties)
- Delay of Game (5 yards) - If the defensive player does not allow an offensive player to get up after the play is over, it is delay of game. This happens most often in the last two minutes of a half when the offense is trying to go down the field in a hurry.
- Running into the kicker (5 yards) - during a kick from scrimmage
- Pass interference
- NFL: An automatic first down and the ball is moved forward to the location of the interference -- a devastating penalty if the play was a long pass. If the interference takes place in the end zone, the ball is placed on the one-yard line.
- College: An automatic first down. Penalty is 15 yards or the spot of the foul, whichever is closer to the previous line of scrimmage. The half-the-distance rule does not apply, unless the previous line of scrimmage was on or inside the 2-yard line. If the ball was snapped between the defensive team's 17-yard and 2-yard lines, and the foul occurred inside the 2-yard line or in the end zone, the ball is placed on the 2-yard line.
- High school: 15 yards and an automatic first down; the half-the-distance rule always applies.
- At any level, if the receiver is interfered with behind the line of scrimmage, the defender cannot be charged with pass interference (although he may be guilty of a different penalty). This nuance in the rules almost never arises, but can conceivably occur on a screen pass. Pass interference is also rendered inapplicable if the ball was tipped by a player on either team prior to the contact being made, regardless of how slight or incidental the "tipping" was.
- Defensive holding or Illegal use of hands (5 yards and an automatic first down; in college, the chains are not moved if the previous play was 1st and 10, making the next play 1st and 5, as in "Offsides" or "Encroachment" above) - illegal use of the hands or arms either while attempting to ward off a block, or to cover a receiver (separate referee's signals are used in these instances; if the infraction involved the defender illegally placing his hands on any part of the fouled player's face, the official will accompany the signal with the words "hands to the face")
- Illegal contact (informally, "illegal chuck," 5 yards and an automatic first down; in college, same exception noted in "Defensive holding" above applies) - any contact made between a defender and a receiver after the latter has traversed more than five yards beyond the line of scrimmage; this rule was adopted in 1978, and its enactment is regarded as contributing to the dramatic increase in both passing yardage and scoring the NFL has witnessed since that time.
- Piling on (15 yards and automatic first down)
- Roughing the kicker (15 yards and automatic first down) - tackling the kicker after he has kicked the ball
- Roughing the passer (15 yards and automatic first down) - tackling the quarterback after he has thrown a forward pass
Penalties against either team
- Too many players on the field (5 yards)
- Grabbing the face mask (5 or 15 yards) - If there is pulling, twisting or turning, 15 yards; otherwise 5 yards. In college, any face mask penalty on the defense results in an automatic first down; in the NFL, only the 15-yard ("flagrant") face mask penalty results in an automatic first down, but in the case of a 5-yard penalty the down remains the same, which can result, for example, in the next play being "1st and 1" if the previous down was 1st and 10 and the ball carrier gained four yards on the play where the foul occurred. The 5-yard penalty will be called when the contact with the face mask is deemed "incidental," but any such contact at all is illegal. In rare cases where an offensive player - particularly a lineman - commits this foul and pulling or twisting is not involved, holding will generally be called instead. This penalty is also occasionally called against a ball carrier who, attempting to "stiff-arm" a pursuing defender, inadvertently touches the latter's face mask; when this occurs a 5-yard penalty would be assessed.
- Unsportsmanlike conduct (15 yards) - Any conduct by anyone involved in the game—usually a player, but occasionally a coach, and very rarely one or more spectators—deemed to be especially objectionable by the game officials, or by rule. Examples include throwing punches, deliberate physical contact with officials, verbal abuse of officials, and taunting, which, since 2004 in the NFL, has included any "prolonged and premeditated celebrations" by players (prior to that year these latter carried only a 5-yard penalty).
- Sideline Violation (5 yards) - Called if a coach or player on the sidelines is on the edge of the field during the snap. An official will usually issue a "Sideline Warning" once before issuing a penalty.
- Palpably unfair act (as necessary) - Called in the case of any action that the officials deem has clearly and indisputably deprived a team of a score. For example, if a player or other person not legally in the game at the start of a given play comes onto the field to tackle a player apparently en route to a touchdown, the team that would have scored is awarded the touchdown. This can also conceivably be invoked in cases where the defense commits repeated intentional infractions very close to its own goal line (the half-the-distance rule making the consequence of such infractions otherwise infinitesimal).
