A domino is a small tile that represents the results of rolling two dice. Each domino has an identifying mark on one side and is blank or identically patterned on the other. There are 28 dominoes in a standard set. Depending on the rules of play, these may be marked with an arrangement of spots (also called pips) or a different pattern such as six-sided stars. The first player to place a domino wins the round.

Dominoes are typically stacked on end in long lines. When the first domino is tipped over, it causes the next domino to fall and so on, forming elaborate geometric designs. Some people also use dominoes as toys, stacking them on their edges to form pyramids and other shapes.

While dominoes are often seen as a game for children, they can also be used to demonstrate scientific concepts, including the “domino effect,” which describes how a simple action leads to much greater—and sometimes catastrophic—consequences. This domino concept can be applied to our lives, as well. One of the most successful business leaders of our time, Ivy Lee, taught her mentor, Charles Schwab, a strategy that relies on this domino effect. She taught Schwab to choose the most important task of his day and to focus all of his energy on that one thing until it was complete. Schwab believed that concentrating all his energy on one activity would generate enough momentum to knock over the rest of his day’s tasks, much like a domino chain.

Stephen Morris, a physicist at the University of Toronto, has studied how dominoes are able to generate such powerful chains. He says that while a domino remains upright, the forces of inertia and friction keep it from moving, but if it is pushed or knocked over, its potential energy gets converted into heat and sound. Then, the energy stored in each domino can be used to push on the next domino in line. Then, it’s just a matter of time before the entire chain falls.

Dominoes can be made from a variety of materials, including bone, silver lip ocean pearl oyster shell (mother-of-pearl), ivory, and dark hardwoods such as ebony. These natural materials offer a more elegant look and feel than polymer sets. Some dominoes are even made from crystal or frosted glass.

The simplest dominoes are made of polymer, but more expensive and durable sets can be found in wood or metal. They can also be carved, inlaid with other materials such as gold, and painted.

While there are many ways to play a game of domino, most involve scoring points by counting the number of pips on an opposing player’s tiles. Doubles may count as one or two (a 6-6 counts as 6 or 12, respectively), and double-blanks can count as either 0 or 14. In some games, the winner is the first player to reach a certain number of points in a specified number of rounds.