In the game of contract bridge, CRASH (an acronym for Color-RAnk-SHape) is a defense against a strong 1♣ or a 1NT opening that first appeared in 1976 in an article by Kit Woolsey in The Bridge World. Within the CRASH framework, intervening calls after the 1NT opening denote either (a) two-suited hands of the same color (black or red), the same rank (major or minor), or the same shape (pointed or rounded) or (b) a natural one-suited hand (hearts or spades). Over a 1NT opening, the following CRASH overcall structure applies: