A domino is a flat, thumbsized, rectangular block that is marked on one side with from one to six pips or dots; 28 such pieces form a complete set. The pips give the domino its identity and determine its value, much as the dots on a die indicate its number value. The other side of a domino is blank or identically patterned to the pips, although a few sets have a different pattern on both sides. When a domino is stood upright, it stores energy based on its position. When a domino is toppled, that energy is transferred to the rest of the dominoes, starting a chain reaction. In a similar way, the energy that causes nerve impulses to travel down a neuron’s axon is converted from potential into kinetic energy.
To start a game of domino, the tiles must be mixed so that players may draw a hand of seven, or more, of dominoes to play with. The player who draws the highest double goes first, and depending on the rules of a particular domino game, he or she must either make the first play, or “buy” some of the remaining tiles left in the stock (see Passing and Byeing).
The tiles are then placed on a table so that the open ends match up. The resulting configuration of the dominoes is called the layout, string or line of play. Depending on the rules of the game, the lines can be played in any direction, although some games have specific instructions for the direction in which a domino is played to a double.
Some games of domino are scored by counting the pips on all four ends of the line of play as it is played. In other games, part of the score is obtained by playing a tile to a double that is already in place. This tile, referred to as the lead, or the lead double, is counted by both players. If the lead double is a spinner, it can be played on all four sides and is called a spinner.
While the mechanics of a Domino game are fairly simple, there are many variations in how to play the game, and this leads to a great deal of creativity by the players. This also allows players of different skill levels to find an enjoyable game that they can play with friends, family or strangers.
Dominoes are a popular party game and have a long history of use in social events. The word “domino” itself has an uncertain origin, but it may have been derived from the name of the Italian city of Domenica, which was once a major center of textile production.
The most common use of the word is in reference to a sequence of events, such as a chain reaction or a series of steps in a process. The phrase has also been used to describe an individual who has a lot of power or influence.