Finding the Important Cards. High-value cards like Aces, Kings, Queens, and Jacks as well as cards that belong to a set or sequence can be considered key cards. In order rummy. olato form melds and a coherent Rummy Bloc, these key cards are essential. Concentrating on Key Cards. Players can concentrate on gathering & holding onto these important cards to create a strong hand by spotting them early in the game. Players are able to prioritize their gameplay and decide which cards to hold or discard with this method.