Domino Tiles and Suits

Bones are generally named for the number of spots on the two ends of the bone. For example, a bone with a 2 on one end and a 5 on the other end is called the 2-5.

Bones that have different numbers on the two ends are called singles, and bones that have the same number on both ends are called doublets or doubles.

Seperate bones that share a common number of spots on one end are said to be of the same suit. In a double-six set, for example, 1-0, 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6 all belong to the suit of one. All singles belong to two suits. The 1-2, for example, belongs to the suit of one and the suit of two. All doubles belong to one suit only.