Football is governed by a set of rules known as the Laws of the Game. These seventeen laws are maintained by the International Football Association Board and apply at every level of the sport, from local youth matches to the World Cup final. Understanding the rules is essential for players, coaches, officials, and fans who want to fully appreciate the sport. This complete guide explains each of the seventeen laws of football, how they are applied, and the reasoning behind them.

Law 1: The Field of Play. Football is played on a rectangular pitch with specific dimensions. For international matches, the length must be between 100 and 110 meters, and the width between 64 and 75 meters. The pitch is marked with boundary lines, a halfway line, a centre circle, penalty areas, goal areas, and corner arcs. The goal measures 7.32 meters wide and 2.44 meters tall. The penalty spot is 11 meters from the goal line. The field markings are not just decorative; they define where different rules apply. For example, fouls committed inside the penalty area by the defending team result in a penalty kick, while similar fouls outside result in a direct free kick.

Law 2: The Ball. The ball must be spherical, made of leather or another suitable material, with a circumference of between 68 and 70 centimeters. It must weigh between 410 and 450 grams at the start of the match. The ball's pressure must be between 0.6 and 1.1 atmospheres. Different competitions may use different specifications, but these standard dimensions ensure consistency across the game. If the ball bursts or becomes defective during play, the game is stopped and restarted with a dropped ball. The introduction of goal-line technology has also required balls to contain sensors in some competitions.

Law 3: The Players. A match is played between two teams, each with a maximum of eleven players, including one goalkeeper. A match cannot start or continue if either team has fewer than seven players. Substitutions are allowed, with the number varying by competition. In most professional matches, teams are allowed three to five substitutions. The use of substitutes has become more flexible since the COVID-19 pandemic, with many competitions allowing five substitutions per match. The goalkeeper must wear colours that distinguish them from other players and match officials. Any player may change positions with the goalkeeper during play, provided the referee is informed and the change happens when play is stopped.

Law 4: The Players' Equipment. Players must wear a jersey or shirt, shorts, socks, shin guards, and footwear. The two teams must wear colours that distinguish them from each other and from the match officials. Goalkeepers must wear colours that distinguish them from all other players and officials. Players are prohibited from wearing anything that is dangerous to themselves or others, including jewelry. Modern equipment has become highly sophisticated, with shirts made from lightweight, moisture-wicking materials and boots designed for specific playing surfaces. Shin guards must be covered by socks and made of suitable material to provide adequate protection.

Law 5: The Referee. The referee has full authority to enforce the Laws of the Game and make decisions on all matters connected with the match. The referee's decisions are final and binding. The referee is responsible for controlling the match in cooperation with the assistant referees and, where applicable, the fourth official and video assistant referees. The referee's tools include a whistle to start and stop play, yellow and red cards to discipline players, and a notebook to record cautions and send-offs. The referee must stop play for serious injuries, ensure player safety, and take action against players who commit persistent offences or show dissent.

Law 6: The Other Match Officials. Assistant referees, also known as linesmen, help the referee by indicating when the ball has left the field of play, which team should take throw-ins, goal kicks, and corner kicks, and when a player is in an offside position. The fourth official assists with administrative duties, manages substitutions, and indicates added time. In modern professional football, Video Assistant Referees review decisions related to goals, penalties, direct red cards, and mistaken identity. The referee always retains the final decision, even when VAR is used. The number of officials has expanded significantly to improve the accuracy of decision-making.

Law 7: The Duration of the Match. A standard football match consists of two equal halves of 45 minutes each, for a total of 90 minutes of play. Half-time lasts no more than 15 minutes. The referee may add time to compensate for stoppages due to injuries, substitutions, time-wasting, disciplinary action, and other delays. This added time, commonly called injury time or stoppage time, can be significant and is displayed by the fourth official. In knockout matches that require a winner, extra time of two 15-minute halves may be played, followed by a penalty shootout if the scores remain level.

Law 8: The Start and Restart of Play. Play begins with a kick-off at the centre of the pitch. A kick-off is also used to restart after a goal has been scored and at the start of the second half and any periods of extra time. All players must be in their own half at a kick-off, and the ball must move forward into the opponent's half. The kicking team cannot touch the ball again until another player has touched it. A goal can be scored directly from a kick-off. When play is stopped for reasons not covered elsewhere, it is restarted with a dropped ball at the position where play was stopped.

Law 9: The Ball In and Out of Play. The ball is out of play when it has completely crossed the goal line or touchline, either on the ground or in the air, or when play has been stopped by the referee. The ball is in play at all other times, including when it rebounds from a goalpost, crossbar, or corner flag, or from the referee or an assistant referee when they are on the field of play. This law is fundamental to understanding when play is active and when it can be restarted, and it underpins the entire flow of the game.

Law 10: Determining the Outcome of a Match. A goal is scored when the entire ball crosses the goal line between the goalposts and under the crossbar, provided no infringement of the Laws has been committed. The team scoring the higher number of goals wins the match. If both teams score the same number of goals or no goals are scored, the match is drawn. In competitions requiring a winner, extra time, away goals (where applicable), and penalty shootouts may be used to determine the result. Goal-line technology has been introduced to assist referees in determining whether a goal has been scored.

Law 11: Offside. A player is in an offside position if any part of their head, body, or feet is nearer to the opponent's goal line than both the ball and the second-last opponent. Being in an offside position is not an offence in itself; a player is only penalized for offside if they become involved in active play by interfering with play, interfering with an opponent, or gaining an advantage from being in that position. The offside rule is one of the most debated and misunderstood laws in football. It is designed to prevent goal-hanging and ensure that attackers cannot simply station themselves near the opponent's goal. Players cannot be offside from a goal kick, throw-in, or corner kick.

Law 12: Fouls and Misconduct. A direct free kick is awarded for kicking, tripping, jumping at, charging, striking, pushing, tackling, or holding an opponent, as well as handling the ball deliberately. A penalty kick is awarded if any of these offences is committed by a player inside their own penalty area. An indirect free kick is awarded for dangerous play, obstruction, impeding the goalkeeper, or offside. Yellow cards are shown for cautionable offences including unsporting behaviour, dissent, persistent infringement, and delaying the restart. Red cards are shown for serious foul play, violent conduct, spitting, denying a goal-scoring opportunity by an offence punishable by a free kick or penalty, and receiving a second yellow card.

Law 13: Free Kicks. Free kicks are either direct, from which a goal can be scored directly against the opposing team, or indirect, from which a goal can only be scored if the ball touches another player before entering the goal. For direct free kicks, the ball must be stationary, and opponents must be at least 9.15 meters from the ball until it is in play. The defending team may form a wall of players to block the shot. Free kicks near the penalty area are prime scoring opportunities, with specialists like Juninho Pernambucano, David Beckham, and Lionel Messi becoming famous for their ability to score directly from free kicks.

Law 14: The Penalty Kick. A penalty kick is awarded for offences punishable by a direct free kick that are committed by a player within their own penalty area. The ball is placed on the penalty spot, which is 11 meters from the goal line. The goalkeeper must remain on the goal line until the ball is kicked. All other players must be outside the penalty area and at least 9.15 meters from the penalty spot. The kicker must kick the ball forward, and no other player may touch the ball until it has been touched by the goalkeeper or has rebounded from the goal. Penalty kicks are high-pressure situations that often decide important matches and tournaments.

Law 15: The Throw-In. A throw-in is awarded to the opponents of the player who last touched the ball when the whole ball crosses the touchline. The thrower must face the field of play, have part of both feet on the ground on or behind the touchline, and use both hands to deliver the ball from behind and over the head. A goal cannot be scored directly from a throw-in. Throw-ins are one of the most common restarts in football and can be a strategic weapon, with some teams practicing long throws to create goal-scoring opportunities, as Rory Delap famously did for Stoke City.

Law 16: The Goal Kick. A goal kick is awarded when the whole ball crosses the goal line after last touching an attacker, without a goal being scored. The ball is kicked from any point within the goal area by the defending team. All opponents must remain outside the penalty area until the ball is in play. The kicker cannot touch the ball again until it has touched another player. A goal can be scored from a goal kick, though this is extremely rare. Goal kicks have become more significant in modern football, with teams increasingly playing out from the back to build attacks rather than kicking long.

Law 17: The Corner Kick. A corner kick is awarded when the whole ball crosses the goal line after last touching a defender, without a goal being scored. The ball is placed within the corner arc nearest to where the ball crossed the goal line. Opponents must remain at least 9.15 meters from the ball until it is in play. The kicker cannot touch the ball again until it has touched another player. A goal can be scored directly from a corner kick. Corner kicks represent a significant goal-scoring opportunity, with teams practicing elaborate routines to maximize their chances of scoring from set pieces.