Like playing cards, of which they are a variant, dominoes bear identifying marks on one side and are blank or identically patterned on the other. The identifying mark, called a pip, is an arrangement of dots or arrows similar to those used on a die, except that some squares are blank (indicated in the listing below by a zero). Each tile has two pips on its outermost edge, and most sets also have pips on the inner edges of the tiles.
Each player begins the game by drawing tiles from the hand, and a domino is then placed on the table so that its pips face up toward the opposing players. The first player to place a domino on the table — either by chance, by a call or knock from an opponent, or by a decision made by the player who holds the highest-valued hand — starts the chain reaction that causes domino after domino to topple.
When the final domino falls, the chain reaction is over and it’s time for the next round. The players then draw tiles from their hands and repeat the process. Generally, play stops when the chain reaches a point at which no players can continue, although some versions of the game require the players to “chip out” when they can’t play their last domino.
The term “domino” derives from the Italian word for domino, but the game did not surface in Europe until the early 18th century. It quickly became a fad, spreading to Italy, Austria and southern Germany before becoming widespread in France.
Traditionally, a domino set is made from bone, silver lip ocean pearl oyster shell (mother of pearl), ivory or a dark hardwood such as ebony, with contrasting black or white pips inlaid or painted on. In addition, there are some sets with the top half thickness in MOP, ivory or ebony and the lower half in a contrasting color such as brass or pewter. Polymer dominoes, meanwhile, have become more popular and more affordable than the traditional types of wood.
A domino’s pips are arranged to indicate its value and determine what number the other end of the tile shows. Each domino has two pips on each end, and the number that is listed is the lowest value, or least common. A domino that has the same pips on both ends is referred to as double. Thus, a domino with a 2 on one end and a 5 on the other is called a double-six.
The most common dominoes have a maximum of 10 pips on the two outermost ends, and this is a very small number. To make more complex games, many sets are extended by introducing additional pips on the other ends of the pieces. Some examples include double-nine, double-12, and double-18 dominoes. This makes it possible to play with up to eight players, but most domino games are played with four or fewer people.