Skip-Bo cards which may be played as any number. Alternatively, the 162 cards could be three regular decks of playing cards, including the jokers, with ace to queen corresponding to 1 to 12 and the kings and jokers corresponding to the SKIP-BO cards. Before 1980, the commercial game consisted of four decks of regular playing cards with eight SKIP-BO cards replacing the standard two jokers in each deck. In addition, the aces, twos and threes in the fourth deck were marked SKIP-BO. The remainder of the fourth deck was discarded. Two to four people can play at a time as individuals,
Zener cards the experimenter picks up a card in a shuffled pack, observes the symbol, and records the answer of the person being tested, who would guess which of the five designs is on the card. The experimenter continues until all the cards in the pack are tested. Poor shuffling methods can make the order of cards in the deck easier to predict and the cards could have been inadvertently or intentionally marked and manipulated. In his experiments, J. B. Rhine first shuffled the cards by hand but later decided to use a machine for shuffling. In his book, "The New Apocrypha",