Dominoes domino sets commercially available are double six (with 28 tiles) and double nine (with 55 tiles). Larger sets exist and are popular for games involving several players or for players looking for long domino games. The number of tiles in a set has the formula formula_1 for a double-"n" set. The most popular type of play are layout games, which fall into two main categories, blocking games and scoring games. The most basic domino variant is for two players and requires a double-six set. The 28 tiles are shuffled face down and form the "stock" or "boneyard". Each player draws
Schläfli double six the Schläfli double six is written 1230. As Schläfli showed, the double six may be constructed from any five lines "a", "a", "a", "a", "a", that are all intersected by a common line "b", but are otherwise in general position (in particular, each two lines "a" and "a" should be skew, and no four of the lines "a" should lie on a common ruled surface). For each of the five lines "a", the complementary set of four out of the five lines has two quadrisecants: "b" and a second line "b". The five lines "b", "b", "b", "b", and "b"