In Gin Rummy, players try to minimize the value of the unmelded cards in their hands while forming melds. A knock indicates that a player thinks they have a winning hand, & the game is over.rummy 500 bonus Indian Rummy, which is played with two decks of cards and permits more intricate melds, is another noteworthy variation. To declare their hand in Indian Rummy, players must form a minimum of two sequences, one of which must be a pure sequence (a run devoid of jokers). With this variation, players must consider their card combinations carefully and add more layers of strategy.