A red card is shown by a referee to signify that a player has been sent off. A player who has been sent off is required to leave the field of play immediately and must take no further part in the game. The player who has been sent off cannot be replaced during the game; their team must continue the game with one player fewer. Law 12 of the Laws of the Game lists the categories of misconduct for which a player may be sent off. These are:
- Serious foul play (a violent foul)
- Violent conduct (any other act of violence)
- Spitting at anyone
- A deliberate handling offense to deny an obvious goal-scoring opportunity by any player other than a goalkeeper in his own penalty area
- Committing an offence that denies an opponent an obvious goal-scoring opportunity (informally known as a professional foul
- Using offensive, insulting or abusive language or gestures
- Receiving a second caution (yellow card) in one game.
:D