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,
42 (dominoes) five or nine), etc. When more than one domino of the same distance from seven is played, the first domino played is considered the winner. A player must bid at least 42 (one mark) to go in sevens, and losing even one trick will set the bidder. When a bid of "sevens" wins the contract, all players reveal their dominoes face-up and order them from sevens to maximum-away. Dominoes must be played in this order by all players. An even less common version of Sevens is looper, where the bidder takes it for less than 42 points (one mark) and