In duplicate bridge, a board is an item of equipment that holds one deal, or one deck of 52 cards distributed in four hands of 13 cards each. The design permits the entire deal of four hands to be passed, carried or stacked securely with the cards hidden from view in four pockets. This is required for in-person duplicate bridge tournaments, where the same deal is played several times and so the composition of each hand must be preserved during and after each play of each deal. When bridge is played online, the functions of the physical boards are replaced by the software.

Duplicate bridge is a variation of contract bridge where the same set of bridge deals are played by different competitors, and scoring is based on relative performance. In this way, every hand, whether strong or weak, is played in competition with others playing identical cards, and the element of skill is heightened while that of chance is reduced. This stands in contrast to Bridge played without duplication, where each hand is freshly dealt and where scores may be more affected by chance in the short run.