Cards are divided in two with two different values: one with a white background, the other on a yellow background. When arranging a hand of several of these cards, you can fan them out to show the white halves, or rotate the hand and fan them out to show the yellow halves instead. These will be two very different hands. The Split Deck Playing Cards box includes two split decks and a rule book explaining how to adapt several games for use with the split decks: rummy, hearts, poker, euchre. For more information, consult the designer's US Patent #4170358