A domino is a small rectangular wood or plastic block with one side bearing an arrangement of dots resembling those on dice. The other side is blank or marked only with a line or a ridge. A set of dominoes can be used to play a number of games. Often the game involves stacking dominoes on end in lines; when the first domino is tipped it causes the others to tip over, and so on. The chain reaction of tips can be elaborate, creating long lines of dominoes that form shapes and figures. Some of the most famous examples of domino art involve stacked walls, or even towers and pyramids.

In modern times, dominoes are most commonly made of polymer, such as acrylic or vinyl. This material is inexpensive, durable and easy to color. In the past, however, dominoes were made of ivory; silver lip ocean pearl oyster shell (mother of pearl); bone or a dark hardwood such as ebony; or metal, particularly brass and pewter. Some sets were also produced in a variety of other materials such as marble, granite or soapstone; woods like ash, oak, redwood and cedar; and even frosted glass or crystal. Such sets, often called bone, stone or agate, are more expensive, but they tend to have a more unique look and feel than polymer dominoes.

Dominoes are most commonly used in positional games, in which a player places a domino, edge to edge against another domino, so that the latter’s identifying marks or pips match those on the former, and that the ends of the two adjacent dominoes add up to a specified total. They may also be used for puzzles, in which the challenge is to place a set of tiles based on a given pattern.

Most domino games are played by two or more players, and the winner is determined when all rounds have been completed. Depending on the game-type or setting, this can be done by counting the points earned by each player, or by playing until a predetermined point limit is reached.

The word domino is also used as a generic term for any game involving the use of dominoes, including positional games, puzzles and scoring games. Many of these are characterized by a high degree of strategy and require careful planning. The popularity of these games has led to the development of computer software programs that allow people to play domino online.

Dominoes are not just for fun; they can be used to create impressive displays that can be photographed and shared online. A YouTube artist known as Hevesh has more than 2 million subscribers, and she’s created spectacular domino creations for movies, TV shows, and events–including a concert by Katy Perry. In her largest setups, Hevesh uses hundreds of thousands of dominoes, which take several nail-biting minutes to fall according to the laws of physics.