Football is a team sport in which players attempt to score goals by passing and dribbling the ball down the field past opposing defenders and kicking or heading the ball into the goal net, outwitting the defending goalkeepers.
At the beginning of the game, choice of ends and the kick off is decided by the toss of a coin. The team winning the toss will have the option of choice of ends or the kick off. The referee having given a signal the game is started by a player taking a place-kick (i.e. a kick at the ball while it is stationary on the ground in the centre of the field of play) into his opponents half of the field of play. Every player is in his own half of the field and every player of the opposing team of the kicker remains not less than 10 yards from the ball until it is kicked off. The kicker will not play the ball a second time until it has been touched or played by another player.
After a goal is scored, the game is restarted in like manner by a player of the team losing the goal.
After half-time, when restarting, ends is changed and the kick off is taken by a player of the opposite team to that of the player who started the game.
The duration of the game is divided into two equal periods of 45 minutes each unless otherwise mutually agreed upon, subject to the following.
Allowances are made in either period for all time lost through substitution, the transport from the field of injured players, time-wasting or other cause, the amount of which matters for the discretion of the referee.
Time is extended to permit a penalty kick taken at or after the expiration of the normal period in either half.
At half time the interval is exceed five minutes except by consent of the referee.
At The ball is out of play, when it has wholly crossed the goal line or touch line, whether on the ground or in the air and when the game has been stopped by the referee.
The ball is in play at all other times from the start of the match to the finish including if it rebounds from a goal post, cross bar or corner flag post into the field of play; off either the referee or linesman when they are in the field or in the event of a supposed infringement of the laws until a decision is given.