Dominoes are small rectangular blocks that can be used as game pieces in a variety of games by matching their ends. Each of the ends may be blank or bearing from one to six pips (dots) in various combinations, with 28 dominoes making up a complete set. A set of dominoes is referred to as a deck, tiles, or a stack.

The term domino has also acquired more figurative uses in contemporary English, particularly when applied to events that are said to have a significant impact on others, such as a tragedy or a disaster that “dominoes” into something larger and more far-reaching than initially intended. The concept of a domino effect is also closely related to the idea of a chain reaction, which refers to a sequence of events that result in a particular outcome, usually for the worse.

In the game of domino, each player begins with a set of dominoes and plays in turn until all the tiles have been played. The remaining tiles are gathered together into a line called the layout, string, or line of play. The line is formed by joining the open ends of adjacent tiles, and the open end of each domino played must touch the next domino in the line.

After the players draw their hands, they must decide who will make the first play by examining their tiles and the rules of the particular game in question. A player who has the heaviest tile in his hand is generally allowed to play first, although this is not always the case and depends on the rules of each game. The first player is also referred to as the setter, downer, or leader.

As dominoes are played, a chain of dominoes is created that gradually increases in length. The number of dominoes in the chain is determined by counting the number of pips on each of the end tiles of each tile that has been played. A domino has no value unless it touches another piece with a number showing at its ends, and the count of a completed chain is known as the score.

Each player may also be permitted to buy a domino from the stock, which is made up of all the tiles that have not yet been played. Buying dominoes from the stock can change the score of the game, and this practice is often prohibited in certain types of games.

A domino artist named Lily Hevesh has a passion for creating intricate displays with these small tiles, and she has become renowned online for her YouTube videos of her work. Hevesh has worked on projects involving more than 300,000 dominoes, and her largest installations can take several nail-biting minutes to fall into place. Hevesh credits physics—and gravity in particular—with helping her to create some of her most impressive designs. See what she has to say in the video below.