

Association football, commonly known as football or soccer, is a team sport played between two teams of eleven players, and is widely considered to be the most popular sport in the world.[1][2][3][4][5] It is a football variant played on a rectangular grass or artificial turf field, with a goal at each of the short ends. The object of the game is to score by manoeuvring the ball into the opposing goal. In general play, the goalkeepers are the only players allowed to use their hands or arms to propel the ball; the rest of the team usually use their feet to kick the ball into position, occasionally using their torso or head to intercept a ball in midair. The team that scores the most goals by the end of the match wins. If the score is tied at the end of the game, either a draw is declared or the game goes into extra time and/or a penalty shootout, depending on the format of the competition.
The modern game was codified in England following the formation of The Football Association, whose 1863 Laws of the Game created the foundations for the way the sport is played today. Football is governed internationally by the Fédération Internationale de Football Association (International Federation of Association Football), commonly known by the acronym FIFA. The most prestigious international football competition is the FIFA World Cup, held every four years. This event, the most widely viewed in the world, boasts an audience twice that of the Summer Olympic Games.[6]
Nature of the game
Football is played in accordance with a set of rules known as the Laws of the Game. The game is played using a single round ball, known as the football. Two teams of eleven players each compete to get the ball into the other team's goal (between the posts and under the bar), thereby scoring a goal. The team that has scored more goals at the end of the game is the winner; if both teams have scored an equal number of goals then the game is a draw.
The primary rule is that players (other than goalkeepers) may not deliberately handle the ball with their hands or arms during play (though they do use their hands during a throw-in restart). Although players usually use their feet to move the ball around, they may use any part of their bodies other than their hands or arms.[7]
In typical game play, players attempt to create goal scoring opportunities through individual control of the ball, such as by dribbling, passing the ball to a teammate, and by taking shots at the goal, which is guarded by the opposing goalkeeper. Opposing players may try to regain control of the ball by intercepting a pass or through tackling the opponent in possession of the ball; however, physical contact between opponents is restricted. Football is generally a free-flowing game, with play stopping only when the ball has left the field of play or when play is stopped by the referee. After a stoppage, play recommences with a specified restart.[8]
At a professional level, most matches produce only a few goals. For example, the 2005–06 season of the English Premier League produced an average of 2.48 goals per match.[9] The Laws of the Game do not specify any player positions other than goalkeeper,[10] but a number of specialised roles have evolved. Broadly, these include three main categories: strikers, or forwards, whose main task is to score goals; defenders, who specialise in preventing their opponents from scoring; and midfielders, who dispossess the opposition and keep possession of the ball in order to pass it to the forwards. Players in these positions are referred to as outfield players, in order to discern them from the single goalkeeper. These positions are further subdivided according to the area of the field in which the player spends most time. For example, there are central defenders, and left and right midfielders. The ten outfield players may be arranged in any combination. The number of players in each position determines the style of the team's play; more forwards and fewer defenders creates a more aggressive and offensive-minded game, while the reverse creates a slower, more defensive style of play. While players typically spend most of the game in a specific position, there are few restrictions on player movement, and players can switch positions at any time.[11] The layout of a team's players is known as a formation. Defining the team's formation and tactics is usually the prerogative of the team's manager.[12]
History and development
Games revolving around the kicking of a ball have been played in many countries throughout history. According to FIFA, the "very earliest form of the game for which there is scientific evidence was an exercise of precisely this skilful technique dating back to the 2nd and 3rd centuries BC in China (the game of cuju)."[13] In addition, the Roman game harpastum may be a distant ancestor of football. Various forms of football were played in medieval Europe, though rules varied greatly by both period and location.
The modern rules of football are based on the mid-19th century efforts to standardise the widely varying forms of football played at the public schools of England.
The Cambridge Rules, first drawn up at Cambridge University in 1848, were particularly influential in the development of subsequent codes, including Association football. The Cambridge Rules were written at Trinity College, Cambridge, at a meeting attended by representatives from Eton, Harrow, Rugby, Winchester and Shrewsbury schools. They were not universally adopted. During the 1850s, many clubs unconnected to schools or universities were formed throughout the English-speaking world, to play various forms of football. Some came up with their own distinct codes of rules, most notably the Sheffield Football Club, formed by former public school pupils in 1857,[14] which led to formation of a Sheffield FA in 1867. In 1862, John Charles Thring of Uppingham School also devised an influential set of rules.[15]
These ongoing efforts contributed to the formation of The Football Association (The FA) in 1863, which first met on the morning of 26 October 1863 at the Freemason's Tavern in Great Queen Street, London.[16] The only school to be represented on this occasion was Charterhouse. The Freemason's Tavern was the setting for five more meetings between October and December, which eventually produced the first comprehensive set of rules. At the final meeting, the first FA treasurer, the representative from Blackheath, withdrew his club from the FA over the removal of two draft rules at the previous meeting, the first which allowed for the running with the ball in hand and the second, obstructing such a run by hacking (kicking an opponent in the shins), tripping and holding. Other English rugby football clubs followed this lead and did not join the FA, or subsequently left the FA and instead in 1871 formed the Rugby Football Union. The eleven remaining clubs, under the charge of Ebenezer Cobb Morley, went on to ratify the original thirteen laws of the game.[16] These rules included handling of the ball by "marks" and the lack of a crossbar, rules which made it remarkably similar to Victorian rules football being developed at that time in Australia. The Sheffield FA played by its own rules until the 1870s with the FA absorbing some of its rules until there was little difference between the games.
The laws of the game are currently determined by the International Football Association Board (IFAB). The Board was formed in 1886[17] after a meeting in Manchester of The Football Association, the Scottish Football Association, the Football Association of Wales, and the Irish Football Association. The world's oldest football competition is the FA Cup, which was founded by C. W. Alcock and has been contested by English teams since 1872. The first official international football match took place in 1872 between Scotland and England in Glasgow, again at the instigation of C. W. Alcock. England is home to the world's first football league, which was founded in 1888 by Aston Villa director William McGregor.[18] The original format contained 12 clubs from the Midlands and the North of England. The Fédération Internationale de Football Association (FIFA), the international football body, was formed in Paris in 1904 and declared that they would adhere to Laws of the Game of the Football Association.[19] The growing popularity of the international game led to the admittance of FIFA representatives to the International Football Association Board in 1913. The board currently consists of four representatives from FIFA and one representative from each of the four British associations.
Today, football is played at a professional level all over the world. Millions of people regularly go to football stadiums to follow their favourite teams,[20] while billions more watch the game on television.[21] A very large number of people also play football at an amateur level. According to a survey conducted by FIFA published in 2001, over 240 million people from more than 200 countries regularly play football.[22] Its simple rules and minimal equipment requirements have no doubt aided its spread and growth in popularity.
In many parts of the world football evokes great passions and plays an important role in the life of individual fans, local communities, and even nations; it is therefore often claimed to be the most popular sport in the world. ESPN has spread the claim that the Côte d'Ivoire national football team helped secure a truce to the nation's civil war in 2005. By contrast, football is widely considered to be the final proximate cause in the Football War in June 1969 between El Salvador and Honduras.[23] The sport also exacerbated tensions at the beginning of the Yugoslav wars of the 1990s, when a match between Dinamo Zagreb and Red Star Belgrade devolved into rioting in March 1990.[24]
Laws of the game
There are seventeen laws in the official Laws of the Game. The same Laws are designed to apply to all levels of football, although certain modifications for groups such as juniors, seniors or women are permitted. The laws are often framed in broad terms, which allow flexibility in their application depending on the nature of the game. In addition to the seventeen laws, numerous IFAB decisions and other directives contribute to the regulation of football. The Laws of the Game are published by FIFA, but are maintained by the International Football Association Board, not FIFA itself.[25]
Players, equipment and officials
Each team consists of a maximum of eleven players (excluding substitutes), one of whom must be the goalkeeper. Competition rules may state a minimum number of players required to constitute a team; this is usually seven. Goalkeepers are the only players allowed to play the ball with their hands or arms, provided they do so within the penalty area in front of their own goal. Though there are a variety of positions in which the outfield (non-goalkeeper) players are strategically placed by a coach, these positions are not defined or required by the Laws.[10]
The basic equipment or kit players are required to wear includes a shirt, shorts, socks, footwear and adequate shin guards. Players are forbidden to wear or use anything that is dangerous to themselves or another player, such as jewellery or watches. The goalkeeper must wear clothing that is easily distinguishable from that worn by the other players and the match officials.[26]
A number of players may be replaced by substitutes during the course of the game. The maximum number of substitutions permitted in most competitive international and domestic league games is three, though the permitted number may vary in other competitions or in friendly matches. Common reasons for a substitution include injury, tiredness, ineffectiveness, a tactical switch, or timewasting at the end of a finely poised game. In standard adult matches, a player who has been substituted may not take further part in a match.[27]
A game is officiated by a referee, who has "full authority to enforce the Laws of the Game in connection with the match to which he has been appointed" (Law 5), and whose decisions are final. The referee is assisted by two assistant referees. In many high-level games there is also a fourth official who assists the referee and may replace another official should the need arise.[28]
Pitch
As the Laws were formulated in England, and were initially administered solely by the four British football associations within IFAB, the standard dimensions of a football pitch were originally expressed in imperial units. The Laws now express dimensions with approximate metric equivalents (followed by traditional units in brackets), though popular use tends to continue to use traditional units in English-speaking countries with a relatively recent history of metrication, such as Britain.[29]
The length of the pitch for international adult matches is in the range 100–110 m (110–120 yd) and the width is in the range 64–75 m (70–80 yd). Fields for non-international matches may be 91–120 m (100–130 yd) length and 45–91 m (50–101 yd) in width, provided that the pitch does not become square. The longer boundary lines are touchlines or sidelines, while the shorter boundaries (on which the goals are placed) are goal lines. A rectangular goal is positioned at the middle of each goal line.[30] The inner edges of the vertical goal posts must be 7.3 m (8 yd) apart, and the lower edge of the horizontal crossbar supported by the goal posts must be 2.44 m (8 ft) above the ground. Nets are usually placed behind the goal, but are not required by the Laws.[31]
In front of each goal is an area known as the penalty area. This area is marked by the goal line, two lines starting on the goal line 16.5 m (18 yd) from the goalposts and extending 16.5 m (18 yd) into the pitch perpendicular to the goal line, and a line joining them. This area has a number of functions, the most prominent being to mark where the goalkeeper may handle the ball and where a penalty foul by a member of the defending team becomes punishable by a penalty kick. Other markings define the position of the ball or players at kick-offs, goal kicks, penalty kicks and corner kicks.