Literary evidence suggests that playing cards existed in China before 1000 AD. Such cards would have been narrow slips of paper, essentially dominoes with dots imitating the twenty-one combinations possible with the throw of two dice. Paper was in fact the original material for dominoes; wood and ivory came later. Domino cards are still known, as is another early Chinese type: money cards, so called because the suit signs are Coins and variations (Tens of Coins, Myriads of Coins.) The use of coin emblems may have derived from the association of cards and money in gambling.