Beer card

In trick-taking card games such as bridge, the beer card is a name informally given to the seven of diamonds (7♦). Players may agree that if a player wins the last trick of a hand with the 7♦, their partner must buy them a beer. This is not considered as part of the rules of these games, but is an optional and informal side-bet between players. This practice likely originates from Danish Tarok or Skat in the middle of the 20th century.^[1] In most decks, the 7♦ is the only diamond number card that lacks rotational symmetry.