Domino, pronounced do-MINO, is an elegant and timeless game that involves building complex chains of dominoes. Normally, each domino is placed so that it touches the ends of other dominoes already on the board. Each player continues to place tiles until their hand is empty or play reaches a point at which the players cannot continue to score. The resulting chain can be an exciting spectacle, a mathematical challenge, or a test of patience and skill.

A small rectangular block of wood or plastic, each face divided into halves and marked with dots resembling those on dice. A set of such blocks, generally 28 in number, is used for playing a game in which the players attempt to make a line of dominoes touching one another, either end-to-end or diagonally.

During the 18th century, European dominoes became popular, with a variety of games being played with them in inns and taverns. The game reached England toward the end of that century, possibly via French prisoners of war. Domino puzzles were also being made around this time and involved placing the tiles based on their arithmetic properties, such as line totals or tile halves.

The word domino probably derives from Latin dominus, meaning “master of the house.” In English, it soon came to refer first to a hooded garment worn together with a mask during carnival season or at a masquerade, then to the hooded costume itself, and finally to the playing piece, which was initially made of ebony blacks and ivory whites, suggesting the similarity in color between the playing pieces and the garment.

Modern domino sets are usually made of polymer materials, such as resin or bakelite, which give them a durable and sturdy feel. They are available in many colors and patterns. Many people, however, prefer the traditional look of dominoes made from bone, ivory, or a dark hardwood such as ebony, with contrasting black or white pips (inlaid or painted). These sets tend to be more expensive than those made from polymer materials.

Larger sets of dominoes, called extended dominoes, are sometimes available in stores, although the most common is a double-nine set. These progressively larger sets add more ends with more pips, which increases the possibilities for a unique combination of ends and thus of pieces. Unlike standard sets, extended dominoes are often not clearly labeled as to the number of pips on each end; in such cases, the player must be careful to identify the pips by examining the backs and edges of the pieces.

In most games of domino, a player plays until they have no more tiles to lay, at which point they must “knock.” If the knocked domino has more than one pips on an edge, it must be replaced with another tile having the same number of pips. The winner is the player whose opponents have no more tiles to lay or a total of more points than their own.