A domino is a tile with a number of dots or spots on its face. These dots, also known as pips, indicate the value of the domino when it is placed on the edge of another tile. A domino with more pips is considered to be of higher rank than a domino with fewer pips. A domino may be made of a variety of materials, including bone, silver lip ocean pearl oyster shell (mother of pearl), ivory, and dark hardwoods such as ebony. The most common dominoes in the United States are molded from clay or bakelite, while those produced in Europe and Asia often have a more elegant look.
Many children enjoy using dominoes as toys by stacking them on end in long lines. When one domino is tipped over, it causes the next domino in the line to tip, and so on. If done carefully, the entire row of dominoes can fall in a very complicated fashion. Such a sequence of events has led to the term “domino effect,” which describes an event that starts with a small action and results in much larger, often dramatic consequences.
Dominoes can be used to play a wide range of games, both competitive and cooperative. The rules for the games depend on how the dominoes are arranged and how many players are playing. Most domino games are played with a set of tiles, called a set of dominoes or simply a set, which includes all the pieces needed for that game. Some of the most popular domino games are bidding games, blocking games, scoring games, and a few positional games.
The most basic domino games are called block-and-draw. The dominoes are shuffled and then each player draws a hand of the pieces required for the game, usually seven. The remaining dominoes are left behind, either on the table or, more commonly, in a boneyard, or “stock.” The player who wins the most points by the end of the game is declared the winner.
A basic rule of domino is that a tile must be played so that its open ends match. This is referred to as a “match.” In some games, matching the two sides of a double may be necessary. The value of a double can be determined by the numbers on the two ends, or by counting the pips on both ends.
Most domino sets consist of twenty-six dominoes, with each domino containing six pips on each of its two open ends. However, there are many different extensions for the set, which increase the number of available combinations of pips on each end.
The reason why a domino’s pips create the chain reaction when the domino is tipped over is that the top of the domino has potential energy, or stored energy based on its position on the surface of the table. When a domino is tipped over, the potential energy is converted to kinetic energy and this pushes on the next domino in the line until it, too, falls over.