The referee may consider serious or persistent offences to be
misconduct worthy of an official caution or dismissal from the game. Association football was the first sport to use
coloured cards to indicate these actions.
Yellow card (caution) A yellow card is shown by the
referee to indicate that a player has been officially cautioned. What constitutes cautionable unsporting behaviour is generally at the referee's discretion, though Law 12 lists a number of examples. In most tournaments, accumulating a certain number of yellow cards over several matches results in suspending the offending player for a certain number of subsequent matches, the exact number of cards and matches varying by jurisdiction (these sanctiones are not regulated by the Laws of the Game). In the
UEFA Champions League, for instance, accumulating two yellow cards in a tournament stage will lead to a one-game suspension. In such situations players have often been suspected of (and occasionally even admitted to) deliberately incurring a second booking in a tournament when the following game is of little importance, thus resetting their yellow card tally to zero for subsequent games (known as "cleaning cards"). However, while technically within the rules of competition, this is considered unsportsmanlike. UEFA has occasionally acted on such choices and has given additional fines and/or suspensions to the players and managers involved. For example,
Sergio Ramos both in 2010 and 2019 picked up extra Champions League suspensions after publicly suggesting during interviews that a yellow card that he accrued was on purpose for card cleaning, the first of which came together with
Xabi Alonso under
José Mourinho's orders. In 2017 IFAB approved temporary dismissals (
sin-bins) for cautionable offences similar to that seen in other sports; however, this is only permitted for youth, veterans, disability and grassroots football. Competitions' use of this system—rather than normal yellow cards—is optional, and there are variations in how it can be implemented. For 90-minute games, the length of the temporary dismissal is 10 minutes.
Red card (dismissal) A red card is shown by a
referee to signify that a player must be sent off. Should a team's on-field players receive a total of 5 red cards, it will be unable to field the required minimum of 7 players, resulting in the match being abandoned. Starting in August 2020 amid the
COVID-19 pandemic,
IFAB and the
Football Association stated that any player who deliberately coughs at others will receive a straight red card. Less severe incidents are classified as "unsporting behaviour" and will result in a yellow card.
History and origin (left of referee) being sent off in the 1966 World Cup. The confusion inspired the adoption of yellow and red cards at the 1970 World Cup. The practice of cautioning and sending off players who make serious breaches of the rules has been part of the Laws of the Game since 1881.
Lothar Matthäus had previously proposed a "lilac card" to distinguish such cases from the more serious "straight red card" offence. With the help of the video assistant referee, it is now possible to upgrade a yellow card to a red card after an on-field review of the infraction. In that case, the referee will show the yellow card, make a no-good gesture, and show the red card to the offending player. ==Frequency==