The Rosenkrantz redouble is used to distinguish between different types of raises in competitive auctions. When one's partner makes an overcall and the next player (responder) makes a negative double, a redouble is used to show a raise which includes the ace or king in the bid suit; an actual raise shows a similar hand but denies a top honor.

This convention is named after its inventor, George Rosenkrantz. Variants include Guildenstern, in which the meanings of the redouble and direct raise are reversed, and Munson, in which the redouble shows a two-card raise including the ace or king. In both cases, the reasoning is that a better hand for the bid suit should raise the level of the auction to make things difficult for the opponents.