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 picks up and sees one or more extra dominoes, those dominoes become part of his or her hand. A player who can play a tile may be allowed to pass anyway. Passing can be signalled by tapping twice on the table or by saying "go" or "pass". Play continues until one of the players has played all the dominoes in his or her hand, calls "Out!", "I win", or "Domino!" and wins the hand, or until all players are blocked and no legal plays remain. This is sometimes referred to as locked down or sewed up. In a common version