Red Card/Origin

Origin
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; his team must continue the game with one less player. Only players, substitutes and substituted players may receive a red card. If a goalkeeper receives a red card another player will be allowed to assume goalkeeping duties (teams will usually substitute an outfield player for another goalkeeper if this option is available). A red card will be shown to a player who has committed a serious offence such as violent conduct or an illegal and purposeful obstruction of a goal scoring opportunity for the opposing team. A red card will also be shown to a player who accumulates two yellow cards for more minor offenses.