Until the rules of Association Football were codified in England in the nineteenth century, most versions of soccer were played without a referee. The position of referee was created along with the first set of rules to keep order on the field during a game. While most elements of football have evolved considerably since then, the role of the referee is very similar to the one performed at the advent of the modern game.
Enforcing the Rules
Referees enforce the laws of the game by penalising foul play as specified in FIFA's rules of soccer. Referees sound their whistle when they wish to stop play and may award free kicks and penalties against a team deemed to be guilty of a foul. If a foul is particularly bad, a referee may award a yellow card against a player. This is a warning and may lead to a red card if a second offence is committed. Referees may show a straight red card, ejecting a player from the game, in the event of serious misconduct or very dangerous play. Referees will also decide contentious issues such as who takes possession when the ball leaves the field of play.
The referee is responsible for timing the game to ensure that 90 minutes are played in two 45-minute halves. The referee will decide how much time to add on at the end of each half to make up for stoppages and ensure the halftime break does not overrun. Referees often wear two or three watches to make sure they keep the correct time.
In addition to penalising fouls and keeping time, referees are responsible for the safety of the players on the field. They must ensure that games are played in the right spirit in an effort to prevent injury to players. This requires good communication skills. Referees may also abandon games in the event of violence, inclement weather or crowd trouble.
Assistant Referees and Fourth Officials
Assistant referees run up and down the line at either side of the field. They help the referee enforce the rules of the game. They are often responsible for calling offside against players as their position gives them the best view of such incidents. They also help with fouls and decisions regarding who takes possession when a ball goes out of play. At elite level, they communicate with the referee via radio but also use a flag to attract attention. Fourth Officials act as a possible substitute for any referees or assistants who get injured. They are positioned among the coaches too and act as a point of contact between them and the officials. In addition to this they oversee the introduction of substitutes.