The requirement that sets and runs must add up to seven or multiples of seven is what makes 777 Rummy unique. For example, a run coulrummy all gamed consist of 4-5-6 of the same suit, or a set could consist of three sevens. Every player starts the game with seven cards. With the top card turned over to begin the discard pile, the remaining cards make up the draw pile, which is arranged face down in the center.
