Football is played according to a set of rules known as the Laws of the Game. The game is played using a single spherical ball, known as the football. Two teams of eleven players each, compete to put the ball into the other team's goal (between the posts and under the bar), thereby scoring a goal. Each team is led by a captain.

The team that scores more number of goals at the end of the game is declared the winner; if both teams score an equal number of goals, the game is declared as a 'draw'.
The players (other than goalkeepers) must not handle the ball with their hands or arms while playing. But they can use their hands during a throw-in restart. Also, they may use any part of their bodies other than their hands or arms to deal with the ball. The players may take the ball in any direction throughout the pitch, though the ball cannot be received in an offside position.

In a typical game, players attempt to create goal scoring opportunities through individual control of the ball, such as by dribbling, passing the ball to a team-mate, and by taking shots at the goal, which is guarded by the opposing goalkeeper. Opposing players try to regain the control of the ball by intercepting a pass or through tackling the opponent in possession of the ball; however, physical contact between opponents is not allowed. Football is generally a continous game, with play stopping only when the ball has left the field of play or when the game is stopped by the referee. After a stoppage, play recommences with a specified restart.

At a professional level, most matches produce only a few goals. The 2005–06 season of the English Premier League produced an average of 2.48 goals per match. Though the Laws of the Game do not specify any player positions other than goalkeeper, but the players may be referred by 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 on their team. 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 of the 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. The players can switch positions at any time. The layout of a team's players is known as a formation. The team's manager defines the team's formation and tactics of the game.

HowProblem.com 2012