Fouls and misconduct

A foul occurs when a player commits a specific offence listed in the Laws of the Game when the ball is in play. The offences that constitute a foul are listed in Law 12. Handling the ball deliberately, tripping an opponent, or pushing an opponent, are examples of "penal fouls", punishable by a direct free kick or penalty kick depending on where the offence occurred. Other fouls are punishable by an indirect free kick.

The referee may punish a player or substitute's misconduct by a caution (yellow card) or sending-off (red card). A second yellow card at the same game leads to a red card, and therefore to a sending-off. Misconduct may occur at any time, and while the offences that constitute misconduct are listed, the definitions are broad. In particular, the offence of "unsporting behaviour" may be used to deal with most events that violate the spirit of the game, even if they are not listed as specific offences. Non-players, such as managers and support staff, may be dismissed from the field and its surrounds by the referee if they fail to conduct themselves in a responsible manner.

Rather than stopping play, the referee may allow play to continue when its continuation will benefit the team against which an offence has been committed. This is known as "playing an advantage". The referee may "call back" play and penalise the original offence if the anticipated advantage does not ensue within a short period of time, typically taken to be four to five seconds. Even if an offence is not penalised because the referee plays an advantage, the offender may still be sanctioned for any associated misconduct at the next stoppage of play.

The offside law effectively limits the ability of attacking players to remain forward (i.e. closer to the opponent's goal-line) of the ball, the second-to-last defending player (which can include the goalkeeper), and the half-way line.