Dominoes spots from one to six are generally arranged as they are on six-sided dice, but because blank ends having no spots are used, seven faces are possible, allowing 28 unique pieces in a double-six set. However, this is a relatively small number especially when playing with more than four people, so many domino sets are "extended" by introducing ends with greater numbers of spots, which increases the number of unique combinations of ends and thus of pieces. Each progressively larger set increases the maximum number of pips on an end by three, so the common extended sets are double-nine, double-12,
Dominoes of laying out dominoes as "pupai", although the character for "pu" had changed, yet retained the same pronunciation. Traditional Chinese domino games include "Tien Gow, Pai Gow, Che Deng", and others. The 32-piece Chinese domino set, made to represent each possible face of two thrown dice and thus have no blank faces, differs from the 28-piece domino set found in the West during the mid 18th century. Chinese dominoes with blank faces were known during the 17th century. Many different domino sets have been used for centuries in various parts of the world to play a variety of domino games.