At its core, Rainbow Rummy adheres to the basic rules of conventional rummy. Combining cards into legitimate sets or runs is the main goal. 767 slotsA run is made up of three or more consecutive cards of the same color, whereas a set is made up of three or four cards of the same rank but different colors. For example, a set could consist of three Kings in various colors, whereas a run could be a sequence like 4-5-6 in blue.