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 also domino games of a very different character are played, such as solitaire or trick-taking games. Most of these are adaptations of card games and were once popular in certain areas to circumvent religious proscriptions against playing cards. A very simple example is a Concentration variant played with a double-six set; two tiles are considered to match if their total pip count is 12. A popular domino game in Texas is 42. The game is similar to the card game spades. It is played with four players paired into teams. Each player draws seven dominoes, and the dominoes are played