Construction and composition of domino sets

European-style dominoes are traditionally made of ivory, bone, or a dark hardwood such as ebony, with contrasting black or white pips (inlaid or painted). Alternately, domino sets have been made from many different natural materials: stone (e.g., marble, granite or soapstone); other hardwoods (e.g., ash, oak, redwood and cedar); metals (e.g., brass or pewter); ceramic clay, or even frosted glass or crystal. These sets have a more novel look, and the often heavier weight makes them feel more substantial, but such materials and the resulting products are usually much more expensive than polymer materials.

The traditional set of dominoes contains one unique piece for each possible combination of two ends with zero to six spots, and is known as a double-six set because the highest-value piece has six pips on each end (the "double six"). The spots from one to six are generally arranged as they are on six-sided dice, but because there are also blank ends having no spots there are seven possible faces, 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-twelve, double-fifteen and double-eighteen. Larger sets such as double-twenty-one can theoretically exist but are rarely seen in retail stores, as identifying the number of pips on each domino becomes difficult, and a double-twenty-one set would have a staggering 253 pieces, far more than is normally necessary for most domino games even with eight players.

History

Domino pieces were historically carved from ivory or animal bone with small, round pips of inset ebony. The game's name comes from the pieces' resemblance to Venetian Carnival masks known as domini, which were white with black spots. These masks were so named, in turn, because they resembled French priests' winter hoods, being black on the outside and white on the inside. The name ultimately derives from the Latin dominus, meaning "lord" or "master."

The oldest domino sets have been dated from around 1120. Modern dominoes, as most of the Western world knows them, however, appear to be a Chinese invention. They were apparently derived from cubic dice, which had been introduced into China from India some time in the distant past. Each domino originally represented one of the 21 results of throwing two dice. One half of each domino is set with the pips from one die and the other half contains the pips from the second die. Chinese sets also introduce duplicates of some throws and divide the dominoes into two classes: military and civil. Chinese dominoes are also longer than typical European dominoes. Over time Chinese dominoes also evolved into the tile set used to play Mah Jong, a game which swept across the United States in the early to mid 1920s and has enjoyed moderate popularity, especially in its "solitaire" form, since that time.