American football, known in the United States (only in English) as simply football, is a competitive team sport that rewards players' speed, agility, tactics, and brute strength as they push, block, tackle, chase, and outrun each other, trying to force a ball further into enemy territory for one hour of game time, which translates into three to four hours of real time. American football is often seen as a metaphor for war, with a great deal of personal violence occurring on every play as players often weighing 300 pounds or more shove each other with every ounce of their strength, and with a clearly defined front line, moving up and down the field, separating the offensive and defensive squads. American football does not much resemble soccer, the sport which most of the rest of the world, except Canada, calls "football". It is a descendant of Rugby Union, and still has recognisable similarities to rugby football.

Table of contents
1 Popularity
2 Naming
3 Professional, college, and other leagues
4 The Game
5 The Field
6 Play Of The Game
7 Advancing the ball
8 Specialized units and players
9 Penalties
10 Development of the game
11 Injuries
12 Football and drugs
13 See also:
14 External Links


Football is extremely popular in the US. In recent years it has surpassed even baseball as the nation's most popular spectator sport. The professional league, the National Football League (NFL), which consists of 32 teams, is very popular. Its championship game, the Super Bowl, is annually watched by nearly half of US television households, and is also televised in over 150 other countries.

College football is extremely popular, with many major colleges and universities playing NCAA (National Collegiate Athletic Association) Division I football, and consistently selling out huge stadiums. College games are widely televised and widely watched. Many colleges in lower NCAA divisions and the NAIA (National Association of Intercollegiate Athletics) have varsity football teams, as do most high schools. There are also amateur, club and youth teams (such as teams in the Pop Warner leagues). In addition to those leagues and teams, now there is a American Football World Cup.


The word football has a number of different meanings. In the United States football almost always means what, in the rest of the English-speaking world, is usually called American football (or in some cases Gridiron football). In most of the rest of the world, the word football means the game that is called soccer in the US, although it is occasionally called Association football or International football. Soccer, the most popular form of football world-wide, is also popular in the US, particlarly as a participation sport for children. It is played at all levels, youth, amateur, high school, college and professional. (see: football (soccer))

The name football might seem a curious name for the sport of American football, as the players' feet rarely have much to do with the ball -- kicking the football is only allowed in certain situations and is most often inadvisable. The vast majority of game time involves players holding the ball in their hands as they run. However, the sport is a direct descendant of rugby union football, as explained below, and has retained the name.

In the remainder of this article, the word football refers to American football.

Professional, college, and other leagues

Football is played at a number of levels in the United States. These include the following. The descriptions on this page are based primarily on the current rules of the National Football League (NFL, 1920-present). Differences with college rules will be noted.

Professional, college, high school, and amateur rules are similar. The minor Arena Football League (1987-present) plays an indoor adaptation of American football, at a faster pace, on a smaller field with no built-in sidelines -- the edges of the grid are coincident with padded walls similar to those found in a baseball outfield. Flag football and touch football are non-tackle versions of American football.

Professional leagues that no longer exist include the World Football League (WFL,1974-75), the United States Football League (USFL,1983-1985), the XFL (XFL,2001), the All America Football Conference (1946-1949), the World League of American Football (WLAF,1991-1993-now NFL Europe), and the league considered by many to be the genesis of modern American professional football,the American Football League (AFL,1960-1969). The NFL merged with the American Football League in 1970, after the AFL began to successfully sign stars from the NFL. After the merger, the NFL adopted innovative features pioneered by the AFL, such as names on player jerseys, official scoreboard clocks (in the NFL, field and scoreboard clocks often did not agree, leading to confusion), and the two-point conversion. Even before the merger, the NFL adopted the AFL's revolutionary concept of network television broadcasts and sharing of gate and television revenues by both the home and visiting teams. Eventually, the NFL adopted virtually every pioneering aspect of the American Football League, except its name.

Since 2000, there has been a surge of women's professional leagues.

The Game

Play in American football consists of a series of individual plays of short duration, between which the ball is not in play. Substitutions are allowed 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, the strategies are complex.

Object of the game

The object of the game is to advance the ball to the opponents' end of the field and score points. The team with the most points when time has expired wins.

Duration, kickoffs and free kicks

The game is 60 minutes long, divided into two halves separated by a halftime. Each half consists of two quarters, each 15 minutes long. Teams change ends of the field after the first and third quarters. If a game is tied at the end of regulation, overtime is played. Overtime periods are "sudden death", meaning that the teams that scores first, by any means, wins.

A kickoff is a special play used to start each half, and also used to restart the game following a field goal, or a conversion attempt following a touchdown. One team kicks the ball, usually from its own 30-yard line, although a kickoff may occur elsewhere due to a penalty 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) and in bounds at least 10 yards away. Once the ball has traveled 10 yards upfield it can be fielded by either team. The ball is usually just kicked deep to the receiving team, but sometimes a team will attempt to recover its own kick, in a play that is known as an onside kick.

A free kick is used to restart the game following a safety, which doesn't happen often. The team that was trapped in its own end zone, and therefore conceded two points to the other team, kicks the ball from its own 20-yard line. A free kick may be punted if the kicking team so chooses.

Methods of scoring

Points can be scored in the following ways.
  • A field goal, worth 3 points, is scored by placing the ball on the ground and kicking it between the uprights of the goal posts. (If a field goal is missed, the ball is returned to the original line of scrimmage [in the NFL, the spot of the kick], and possession is given to the other team.)
  • A touchdown, worth 6 points, is achieved when a player has legal possession of the ball within the opponents' end zone. Scoring a touchdown is the ultimate goal of the offensive team.
  • One or two extra points may be scored following a touchdown. The team which scored the touchdown is given a conversion attempt (also called a "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 which they may score either one or two additional points. The defending team can only score during a conversion attempt by the other team in college football, where if a defender gets possession of the ball and carries it into the opposing end zone, his team gets two points. This rule was adopted by the NCAA in 1990, but is not used anywhere else.
    • An extra point, worth 1 point, is scored in the same way as a field goal is scored during regular play.
    • A two-point conversion is scored in the same way as a touchdown is scored during regular play.
  • A safety, worth 2 points, is scored when a player is either tackled or goes out of bounds within his own end zone, in either case while carrying the ball.

The Field

The field

The field is a rectangle 120 yards long and 53 1/3 yards wide, defined by sidelines running the length of the field and endlines running the width. There is a goal line ten yards in from each end line and parallel to it. The two goal lines are thus 100 yards apart. The area of the field between the goal lines is called the field of play. At each end of the field, the end zone is the area between the goal line and the end line.

Within the field of play, additional markings include yard markers, as well as inbound lines (also called hash marks), every yard the length of the field. The inbound lines (hash marks), which are short lines perpendicular to the yard markers, are 70-3/4 feet from the sidelines in the NFL. (Note: the hash marks are closer to the sidelines in college football) Every 5 yards, the yard markers run the width of the field, and every 10 yards, they are marked by numbers indicating the distance, in yards, from the nearest goal line.

At the center of each end line is a set of goal posts, which have two upright posts extending above a crossbar. The distance between upright posts is 18-1/2 feet, and the top of the crossbar is 10 feet above the ground.

Play Of The Game

A game consists of many individual plays. The vast majority of these are scrimmage plays. Each play from scrimmage is one of a series of downs given to the team with possession. These two concepts, the concept of scrimmage, and the concept of downs, are fundamental to American football, and are what distinguish it, as well as Canadian football, from most other forms of football.

A set of downs begins with a first down, which is given to a team either after it has just gained possession on the previous play, or it has gained the necessary yardage from a previous set of downs. On a first down, the team with possession is given four downs to gain 10 yards (they have "a first and ten", meaning that it is first down, and they need ten yards to get another first down). The line a team must reach in order to gain a first down is technically called the line to gain, although it is commonly called first down yardage. The team with possession is called the offensive team, and the other team the defensive team.

Plays from scrimmage

Each down is a play from scrimmage. Prior to each play from scrimmage, the two teams line up on opposite sides of a line of scrimmage, which is defined by the spot of the ball from the previous play. The spot is, in most cases, the yard line at which the ball became dead on the previous play, plus or minus any penalty yardage. A down, or play from scrimmage, begins with a snap and ends when the ball becomes dead for any reason. A snap is either a handoff between the legs from the center to the quarterback, or it is a pass between the legs from the center to the quarterback, or possibly to a player other than the quarterback, such as a punter or a holder for a field goal attempt. The ball may become dead, ending the down, because a player in possession is tackled, or because his forward progress is stopped, or because he goes out of bounds, or because a forward pass goes incomplete.

Advancing the ball

There are two methods that can be used to advance the ball while still maintaining possession:

It is important for the offense to run a variety of running and passing plays in order to keep the defense uncertain of the next play. If the quarterback has two broken fingers on his throwing hand, for example, the defense can safely risk lining up in a run defense for nearly every play, which should successfully squelch the offense's running backs.

Fourth down situations

If a team uses all four of its downs without gaining the yardage for a first down, possession goes to the other team. Fourth down situations are therefore pivotal. The offense has three choices: "go for it", punt, or attempt a field goal.

Things the offense may decide to do on fourth down:

  • "go for it" - If the distance required for a first-down is short, a team may elect to go for it -- mount a regular running or passing play -- on fourth down, but this is often risky: failing to make the next first down gives the ball to the opposing team, usually with much better field position than a kick would leave them with. The safe thing to do is usually to kick the ball.
  • punt - A team will punt in order to gain better field position.
  • attempt a field goal - Field goal attempts must be made with the ball on the ground (they cannot be punted), so a player called a holder holds the ball for a kicker. (In times past, a kicker might have tried a "drop kick" -- that is, droping the ball and kicking it after it bounces off the ground -- and if the kicker kicks it through the goalposts, it is a field goal. This is difficult to do, as the ball is in the shape of a prolate spheroid and its bounce is unpredictable. Nowadays, the only time you will see this is by a hurried kicker after a broken play.) Failed field goal attempts, if they are short, can be returned by the opponent, but the ball usually goes past the end line and can't be returned. If the field goal attempt fails, the ball is spotted at the original line of scrimmage, and possession is given to the other team. (In the NFL, failed field goal attempts are spotted at the spot of the kick.)

A team will occasionally run a trick play on fourth down. They will line up as if to punt or attempt a field goal, but will instead run the ball or pass it in an attempt to pick up a first down.

Specialized units and players

With its unlimited substitutions, American football is highly specialized, with most teams having three specialized units: an offensive unit, a defensive unit, and special teams. There are many specialized players within each units. Some players may only be used in certain situations. (for details see: offensive unit, defensive unit, special teams.)


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 a penalty against the offense. A penalty against the defense 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. A personal foul, which involves danger to another player, usually results in a 15 yard penalty.

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 when the ball is snapped, with the exception of the center.

Penalties against the offense

  • False start (5 yards) - a lineman moving before the snap in a way that simulates the start of the play
  • Illegal motion (5 yards) - having more than one back in motion at the snap
  • Illegal shift (5 yards) - not being set before the snap
  • Illegal formation (5 yards) - having less than 7 players on the line of scrimmage
  • Delay of game (5 yards) - allowing too much time to elapse before the snap
  • Ineligible receiver downfield (5 yards) - a lineman beyond the neutral zone prior to a forward pass
  • Illegal forward pass (5 yards and loss of down) - thrown from beyond the neutral zone, or a second forward pass on the same play.
  • Holding (10 yards) - illegal use of the hands or arms while blocking
  • Offensive pass interference (10 yards) - interfering with a defender attempting to catch a pass
  • Intentional grounding (10 yards and loss of down) - throwing the ball into the ground to avoid being tackled
  • Clipping (15 yards) - an illegal block from behind below the waist
  • Illegal block (15 yards) - usually a "crackback block".

Penalties against the defense

  • Offsides (5 yards) - making contact with an offensive lineman before the ball is snapped. or being in the neutral zone when the ball is snapped. The offense can decline the penalty and take the yardage gained on the play.
  • Running into the kicker (5 yards) - during a kick from scrimmage
  • Pass interference - in the 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. In college and high school football, 15 yards and an automatic first down.
  • Piling on (15 yards)
  • Roughing the kicker (15 yards) - tackling the kicker after he has kicked the ball
  • Roughing the passer (15 yards) - 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 intentional, 15 yards; if unintentional, 5 yards. Just touching an opponent's face mask, without grabbing it, is not illegal.

Development of the game

American football in its current form grew out of a series of three games between Harvard University and McGill University of Montreal in 1874. McGill played by the Rugby Union code while Harvard played the Boston Game, which was closer to Association Football. As often happened in those days of far from universal rules, the teams alternated rules so that both would have a fair chance. The Harvard players liked having the opportunity to run with the ball, and in 1875 persuaded Yale University to adopt Rugby Union rules for their annual game. In 1876 Yale, Harvard, Princeton, and Columbia formed the Intercollegiate Football Association, which used the Rugby Union code, except for a slight differnce in scoring.

In 1880 Walter Camp introduced the scrimmage in place of the rugby scrum. In 1882 the system of downs was introduced to thwart Princeton's and Yale's strategy of controlling the ball without trying to score. In 1883 the number of players was reduced, at Camp's urging, to eleven, and Camp introduced the soon standard arrangement of a seven-man offensive line with a quarterback, two halfbacks, and a fullback.

On September 3, 1895 the first professional football game was played, in Latrobe, Pennsylvania, between the Latrobe YMCA and the Jeannette Athletic Club. (Latrobe won the contest 12-0.).

By the 1890s interlocking offensive formations such as the flying wedge had made the game extremely dangerous. Despite restrictions on the flying wedge and other precautions, in 1905 eighteen players were killed in games. President Theodore Roosevelt informed the universities that the game must be made safer. However, it was not until 1910, and after further deaths, that interlocking formations were outlawed.

The forward pass was introduced in 1906. In 1912 the field was changed to its current size, the value of a touchdown was increased to 6 points, and a fourth down was added. The game had achieved its modern form.


Despite the helmets and heavy padding worn by all players on the field, injuries are common in football. An "Injury Report" section is ubiquitous in American newspapers' sports sections, detailing each injured player on each team with his injury listed and the amount of time he is expected to be out. Around the middle of each week, all NFL teams report the status of their injured players as "out" (will not play in the coming game); "doubtful" (25% chance of playing); "questionable" 50% chance of playing); or "probable" (75% chance of playing). A similar system is used in all American professional sports.

An average of about eight players die each year in the United States as a result of injuries received in games at all levels. About 160 concussions occur every season, and the National Football League now collects benchmark awareness measures for each player which can be used during a game to determine whether he has been concussed.

The injuries sustained by football players often are permanent. Many former football players experience pain, sometimes severe, that lasts for the rest of their lives. Often players require surgery, even multiple surgeries, for injuries experienced years earlier.

Interestingly, newspaper reporters who have interviewed former football players who are crippled or in pain as a result of their former sport find that a player will never (or virtually never) express regret over his choice of career. The players often state that the thrill of playing football was worth paying for with a lifetime of subsequent pain.

Football and drugs

Contemporary football players are larger than their predecessors of only 30 or 40 years ago. It is quite normal, for instance, for all the members of the offensive line of a major college or professional team to weigh more than 300 pounds (136 kg.), whereas in the 1960's linemen who weighed only 270 pounds were common. The increase in player size has led to a increase in the frequency and severity of injuries.

Since nutritional standards and weight training technique were already quite advanced even in the 1960's, it has been conjectured that much of the increase in the size of the players is the result of the widespread availability of illegal anabolic steroids, which increase the growth of muscle tissue. Such drugs are widely available even to high school players.

Because anabolic steroids have dangerous side effects, the National Football League tests its players for steroids and penalizes those who are caught. However, it has recently emerged that new varieties of steroids are being developed in clandestine laboratories, which elude existing drug tests. Hence there is a kind of "arms race" between the scientists who develop new kinds of illegal steroids and those who develop tests to detect them.

See also:

External Links