A domino (plural: dominoes) is a flat, thumb-sized rectangular block with one face bearing an arrangement of dots or pips similar to those on dice. The other face is blank or identically patterned. The domino is used for a variety of games that involve arranging and laying the pieces down in lines and angular patterns.

The most common commercially available set of dominoes consists of 28 tiles. Sets are also available with more than that number, but they are rarely used for games involving more than four players. The most popular types of play for dominoes fall into two broad categories: blocking games and scoring games.

In many games, the player who successfully lays down all of his or her dominoes wins the hand. When a player is unable to do so, the game ends and the players swap hands. In some games, the player who lays down the first domino in a chain is awarded points for that tile and the dominoes around it. These points are added to the total score for the hand and may be used in future hands.

Dominoes can be made from a wide variety of materials. Most sets are constructed of polymer such as styrene, but some are made from natural materials, such as bone, silver lip ocean pearl oyster shell (mother of pearl), ivory, or a dark hardwood such as ebony with contrasting black or white pips. Such sets usually have a greater weight and feel more substantial than those constructed of polymer. They may also be carved or painted in various designs.

Each domino is unique, but most are grouped into suits that correspond to the numbers of their pips. Each domino in a suit must have matching ends and must not be double-ended. For example, a single-ended domino has six pips and belongs to the suit of sixes; a double-ended domino has three pips and belongs to the suit of threes. Other possible combinations of pips on the ends of a domino give rise to other suits, such as the suit of eights.

The game of domino grew in popularity worldwide in the late 19th and early 20th centuries. Its widespread use was helped by the introduction of inexpensive, mass-produced dominoes from the United States and Italy. In recent years, the number of different types of dominoes and games has increased.

Dominoes are also a popular teaching tool for children, as they can be used to demonstrate simple addition, subtraction, multiplication, and division. In addition to these basic math skills, dominoes help develop visual perception and motor coordination. They are a good choice for family gatherings and parties because they allow guests of all ages to interact in an engaging way. Whether you enjoy dominoes on your own or with friends and family, it is important to understand the rules of the game before playing. This will ensure that you and your opponents have a fun and enjoyable time!