The objective of this variation is to create legitimate sets and sequences before declaring a hand after each player is dealt 13 cards from a standard deck. There are usually two decks inviprummy the game, and up to six players can participate. Since players must predict their opponents' moves while controlling their own hands, 13 Card Rummy's strategic depth comes from a combination of deft card play and psychological strategies. Contract Rummy, which introduces a sequence of contracts that players must fulfill over several rounds, is another popular variation.