Domino is a small rectangular block used as gaming pieces. The surface of a domino is divided into two square halves and has a number of dots (or absence of spots) that represent numbers; the most common sets have either black or white dots. In the game of domino, players place tiles edge-to-edge across a line to form chains. The end of each tile shows a particular number, which is the total value that must be achieved if the chain is to be completed. A player wins by reaching a total of zero or more points before the opponents. The name comes from the Latin domino, which means “lord” or “master.” It is an apt word for a game that encourages the player to think ahead and plan accordingly.
The physics of a domino is simple enough: Each domino has a center of gravity, and when it’s standing upright, it has potential energy. The moment you knock it over, however, the potential energy converts to kinetic energy as it falls toward Earth. This energy of motion then affects the next domino, and so on, in a cascade of movement that sometimes results in spectacular designs.
This is also the principle behind the phrase domino effect: One tiny action can lead to much greater, and sometimes even catastrophic, consequences. Whether it’s a person tripping over a block or a business collapsing under the weight of its debt, these dominoes can quickly cause a chain reaction that is difficult to reverse.
A domino is most commonly used for positional games. Each turn, a player places a domino on the table positioning it so that its ends touch with adjacent tiles (one’s touching one’s, two’s touching two’s, etc.). Then, if the exposed pips add up to a certain multiple of five—normally a value useful to the player or distasteful to their opponents—the player scores that amount.
There are numerous domino games, but they all share a similar theme. The most popular domino games involve scoring points by forming chains of tiles that display a specific total. Players may also compete to build the longest chain or the most elaborate structure in which a single domino can be found.
Dominoes are usually made of wood, but they can be made of any material. They are typically molded or drilled, and colored by painting. They can be found in many different colors, but white is most popular and is the standard for most domino games. In addition to traditional blocking and scoring games, several non-competitive domino games are also available that allow the players to work on their concentration skills or to practice arithmetic. Some of these games use cards instead of dominoes, but they have the same general gameplay as dominoes. They are most often played by four players and can be extended to eight or more players by using progressively larger sets such as double-twelve (91 tiles) or double-nine (55 tiles). Some of these games are adaptations of card games that were popular in the past in some areas to circumvent religious proscriptions against playing cards.