A defender trips an attacker who had a clear path toward goal. The official blows the whistle and signals a free kick. That illegal action is a foul. Fouls protect player safety and the fairness of the contest.

Each sport defines its own catalogue of fouls—illegal contact, dangerous play, handling the ball, delay of game, and many others. Officials decide severity and may issue warnings, free opportunities, or dismissals. Repeated or reckless fouls escalate consequences.

Players sometimes commit tactical fouls to stop counter-attacks, accepting the punishment to prevent a greater threat. Officials must distinguish between accidental contact, legitimate toughness, and genuine offenses. Consistent foul recognition shapes the character of a match.

• Illegal action that violates the rules of play
• Penalized to protect safety and fairness
• Severity ranges from free kicks to send-offs
• Can be accidental, reckless, or tactical