Domino is a small, rectangular block of wood or plastic that has a line down the center and each end bears one to six dots, which are called pips. These pips can be painted or inlaid. Dominoes can be stacked on end to form long lines or in angular patterns. They are often used to play a variety of games, and some of the most famous include:
Domino has also become a metaphor for something that happens by accident or as a side effect. A well-known example is the Domino Effect, which states that if you change one behavior, such as eating more healthy food or exercising more, other behaviors will change as a natural consequence. For example, if someone starts to exercise more, they will likely spend less time on the couch watching television or eating junk food. These changes will lead to better overall health.
A domino set consists of 28 unique tiles. The most popular type is a double six set, which has six spots on each end. Other sets exist that have more or less than six spots on each end, but these are generally used for longer games. Some sets use Arabic numerals instead of pips to make it easier to identify the number of spots.
Traditionally, dominoes are made of bone (silver lip ocean pearl oyster shell), ivory, or a dark hardwood such as ebony with contrasting black or white pips. More recently, dominoes have been produced in a wide variety of materials. Some of these are plastic, but others have a more organic feel and can be quite heavy in weight. Some sets are even made of glass or ceramic clay, which can make them more durable than polymer ones.
Most domino games are played by placing a tile edge to edge against another, either the one that is already on the board or the one that the player intends to play. The player scores points by laying down the tiles so that their exposed ends match, i.e., one’s touch two’s, or that the sum of all the exposed pips is some specified value. The first player to reach the point value wins the game.
In general, the higher the number of pips on a tile, the more valuable it is. However, in many games the number of pips is not important and identifying the color or type of the pips is more relevant. For this reason, some domino sets are sold with the pips removed and only the shape remains to make them more easy to identify. This variation is also sometimes referred to as “domino-style.”