<P> The longer boundary lines are touchlines, 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 . The inner edges of the vertical goal posts must be 24 feet (7.3 m) apart, and the lower edge of the horizontal crossbar supported by the goal posts must be 8 feet (2.4 m) above the ground . Nets are usually placed behind the goal, but are not required by the Laws . </P> <P> In front of the goal is 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 . </P> <P> A standard adult football match consists of two halves of 45 minutes each . Each half runs continuously, meaning that the clock is not stopped when the ball is out of play . There is usually a 15 - minute half - time break between halves . The end of the match is known as full - time . The referee is the official timekeeper for the match, and may make an allowance for time lost through substitutions, injured players requiring attention, or other stoppages . This added time is called additional time in FIFA documents, but is most commonly referred to as stoppage time or injury time, while loss time can also be used as a synonym . The duration of stoppage time is at the sole discretion of the referee . Stoppage time does not fully compensate for the time in which the ball is out of play, a 90 minute game typically involves about an hour of "effective playing time". The referee alone signals the end of the match . In matches where a fourth official is appointed, towards the end of the half the referee signals how many minutes of stoppage time he intends to add . The fourth official then informs the players and spectators by holding up a board showing this number . The signalled stoppage time may be further extended by the referee . Added time was introduced because of an incident which happened in 1891 during a match between Stoke and Aston Villa . Trailing 1--0 and with just two minutes remaining, Stoke were awarded a penalty . Villa's goalkeeper kicked the ball out of the ground, and by the time the ball had been recovered, the 90 minutes had elapsed and the game was over . The same law also states that the duration of either half is extended until the penalty kick to be taken or retaken is completed, thus no game shall end with a penalty to be taken . </P> <P> In league competitions, games may end in a draw . In knockout competitions where a winner is required various methods may be employed to break such a deadlock, some competitions may invoke replays . A game tied at the end of regulation time may go into extra time, which consists of two further 15 - minute periods . If the score is still tied after extra time, some competitions allow the use of penalty shootouts (known officially in the Laws of the Game as "kicks from the penalty mark") to determine which team will progress to the next stage of the tournament . Goals scored during extra time periods count towards the final score of the game, but kicks from the penalty mark are only used to decide the team that progresses to the next part of the tournament (with goals scored in a penalty shootout not making up part of the final score). </P>

How many minutes are in a professional soccer game