Strategic Involvement. Players stay engaged in Contract Rummy because of its dynamic and adaptable nature, which allows them to constantly modify their strategies to fit the shifting needs of each round anviprummyd outmaneuver their rivals. A less well-known variation that adds a distinctive twist to the classic rummy gameplay is Oklahoma Rummy. Two decks of cards are usually used for play, and two to six players can participate. The wild card system used in Oklahoma Rummy is based on the first card drawn from the stockpile at the start of each round; if the card is numbered, that number becomes wild for that round.