Rummy 51's rules are rather simple, but it may take some time & practice to become proficient with the subtleties. Players must construct legitimate melds, which are made up of runs (three or more consecutive carslot appsds of the same suit) or sets (three or four cards of the same rank). Also, the game features a special scoring system in which players lose points for unmelded cards left in their hands after another player leaves and gain points for the cards they have melded. Players must strike a balance between trying to meld their cards & monitoring the progress of their opponents, which adds another level of strategy to the game.