Double play is a series of 12 interchangeable trivia card games for 3 or more players. Each box contains rules for 1 simple game, 101 trivia cards, 3 blank cards and 4 mystery cards. All double play decks can be combined to make larger decks. All cards are splash proof plastic. All decks can also be used as an expansion pack for double vision. Cement shoes is a game of elimination. Players that collect two "cement shoes" sleep with the fishes.