A "red card" is a disciplinary tool used in sports, particularly in soccer, to indicate that a player has committed a serious foul or misconduct. When a referee shows a red card, the player must leave the field immediately and cannot be replaced, leaving their team with one fewer player for the remainder of the match. Receiving a red card can result from various offenses, such as violent conduct, using offensive language, or receiving two yellow cards in a single game. Players who receive a red card may also face additional penalties, including suspensions for future matches, depending on the severity of the offense.