A domino is a small rectangular block of wood or plastic, with either blank or numbered ends, and it is used to play many games. Each end has a number of spots or pips that differ from one another, with the most common set having six pips on each side and other sets with fewer or more pips on each end. These small blocks of varying sizes are also called bones, cards, men or pieces. Dominoes can be made in many different materials, and can be colored to match a game or theme. They can even be sculpted into shapes such as people, animals or buildings, and can stand up in a tower formation.
Some dominoes have a line down the middle to separate them visually into two squares, each having a value of spots or pips, ranging from six pips (most common) down to none or blank. The sum of the values on both sides of a domino is its rank or weight, and this can be important in some games.
In a typical domino game, players take turns playing tiles by matching the open end to the pips on the previous tile played. When a player plays a domino, it must be joined to the line of play in some way – if it has a double in its open end, this may be done crossways, or lengthwise depending on the rules for the game.
Once all the hands have been played, and the final tile in a player’s hand has been set down, the remaining tiles form a line of play, which is referred to as the string or layout. This configuration of the remaining tiles is often a major part of the game’s challenge and can be a significant factor in the winner of a particular match. Some games have special rules for determining which player makes the first play, with some requiring the winner of the previous game to make the first play.
The basic rules for most domino games specify that the heaviest tile must be placed first in order to create the line of play. If a tie exists between the heaviest and next heaviest dominoes, a draw is usually performed to determine which player makes the first play.
Some physicists have suggested that the simple act of standing a domino upright can result in a chain reaction. When a domino is tipped ever-so-slightly by a player, its potential energy is converted to kinetic energy which causes it to topple over and join the line of others.
When a domino chain reaches its end, the remaining tiles are usually stacked to form an art display such as a building or picture. This can provide a great deal of entertainment for spectators, and is commonly seen in domino shows, where builders attempt to construct amazingly complex structures before an audience of fans. Those who have the patience and creativity to design elaborate domino art can create stunning pieces that are truly amazing to see in person.