Abstract: With conventional playing cards, when a game player holds together cards (the hand) in his/her hand during a game, if the cards are held shifted from each other, the indexes of all the cards in the corners thereof can be seen. If someone commits cheating (peeking) for the purpose of fraud, such third person can know all the cards held by the game player. Playing cards of the present invention can prevent fraudulent acts such as peeking in card games. Playing cards (1) form a single deck with fifty two cards, and are made up of two types of cards, namely, cards (1a) having an index (2), which indicates a numerical value that represents a rank, only in the upper left and lower right portions thereof, and cards (1b) having the index (2) only in the upper right and lower left portions thereof.