Domino, also called dominoes or domino blocks, are a set of square, rectangular or round pieces of wood, bone, ivory or ceramic clay with one or more dots (also known as pips) on each end. The pips may be inlaid or painted, giving the pieces a more decorative look and feel. Modern domino sets are typically made from polymer materials such as plastic or melamine. However, historically, dominoes were made from many different natural and semi-natural materials: bone or ivory; dark hardwoods such as ebony or birch; various types of stone (e.g., marble or soapstone); metals; and even glass or crystal. In the past, some sets were handcrafted from materials such as acacia, mahogany or ebony for a more distinctive look and higher quality.
Although dominoes are primarily used for scoring and blocking games, they can also be played in ways that require more strategy and skill. For example, players can try to make a line of dominoes that goes from one end to the other, counting each piece as it falls. In addition, dominoes are often used to illustrate mathematical relationships; for instance, the number of pips on a given end may represent a fraction or a multiplication table.
A popular game that involves counting each domino as it is placed is called Counting Up. The objective is to see how far a player can go without having to add more dominoes to the line. A player who succeeds in this challenge wins the game.
Another popular domino game is the scoring version of Fives-and-3s, where players score points by attaching a new tile to the ends of those already laid down so that the sum of the two sides is divisible by either five or three. In this game, a double is considered a “heavy” domino, while a single-blank is a “light” domino.
In addition to these traditional domino games, people use dominoes to create artistic structures such as curved lines, grids that form pictures when they fall, or 3-D structures like towers and pyramids. Some artists make test versions of each domino layout on a flat surface to ensure that it will work before putting the finished construction together. In some cases, domino art is so elaborate that it becomes a form of performance: Domino builders compete to build the most impressive and imaginative domino reaction or effect before an audience of fans.
Before a game or hand of domino begins, the tiles are shuffled so that each player cannot easily determine which piece they have in their hand. A collection of shuffled tiles is known as the boneyard. The first player places the starting domino on the boneyard, usually a double-six. The value of a domino is determined by its position on the edge and the number of pips it has on both ends; the more pips on a domino, the higher its rank or weight. Traditionally, the rank of a domino was determined by its ability to stop other players from drawing additional tiles.