Melds may consist of three of a kinds, four of a kinds, or runs of 3+ cards in sequence.
That mechanism is matching cards or creating sets or melds of cards based on certain constraints. Rummy is viewed as a family of games which rely on a similar mechanism. This style of gameplay traveled outside Eastern Asia at the start of the 20th century. The widespread view is that Rummy games are of Chinese origin, although they are now extremely popular across the globe.
