
In the game of contract bridge, a convention is an agreed-upon meaning for a call (a bid, double or redouble, or a pass) during the auction phase of the hand. Often, the inventor of the convention gives it a name; some widespread conventions got a name after their (perceived) authors.
Conventional opening leads and discards may also be used. The term, however, usually denotes just a bidding convention.

The card game auction bridge was developed from straight bridge and was a predecessor to contract bridge. Around the same time five hundred was created by the United States Playing Card Company in 1904.

In an auction, bid shading describes the practice of a bidder placing a bid that is below what they believe a good is worth.

Two partnerships of two players each are needed to play bridge. The four players sit around a table with partners opposite one another. The compass directions are often used to refer to the four players, aligned with their seating pattern. Thus, South and North form one partnership and East and West form the other.