A domino is a small rectangular wood or plastic block, typically 28 in number. Each of its two faces is marked with an arrangement of dots resembling those on dice. The word derives from a Latin term meaning “little table.” Domino is also used as a noun to refer to the game of dominoes or a set of these pieces.
The most common domino games involve scoring points by counting the pips (spots) on the ends of tiles in a line of play. Other games focus on emptying players’ hands or blocking opponents’ plays. Some of these games duplicate card games, while others help children recognize and count numbers.
Some games use a fixed set of rules, while others are open to various variations in the rules. The rules of a particular game are spelled out in the instructions printed on or accompanying the game board, or in a rule book. Many games also have a certain amount of variation among different players and between locations and countries, though there are a few that are almost universally played in one form or another.
In addition to the basic rules of a game, the order of play in a domino game can vary. The player who makes the first play is referred to as the setter, downer, or lead. He or she should place his tile face up on the table and then begin matching its end to part of a preceding tile. The resulting line of play is known as the layout, string, or line of play.
Once the line of play has been established, players may begin playing dominoes in either direction. In most cases, however, the shortest end of a preceding tile must be placed in the same direction as that of the new piece. For example, a 5-5 double must be played lengthwise, and a 3-3 crosswise.
After each player has drawn a hand of dominoes, the unused tiles are called the stock. They are then reshuffled and restocked. A player who draws more dominoes for his hand than he is entitled to is said to overdraw. The extra tiles must be removed from his hand and returned to the stock before anyone else draws their hands.
The earliest known dominoes were made in Italy and France, and were introduced to England by French prisoners toward the end of the 18th century. The most common domino sets have 91 or 55 tiles, with each set having a specific number of pips on each end. Larger sets are sometimes “extended” by adding additional pips to the existing ends, which increases the number of possible combinations of ends and thus of dominoes. There are also smaller sets with a fixed number of dominoes, which are suitable for use by young children.