A domino is a flat tile with pips (small dots) on one side and a square end. When stacked together in a line, each domino can be tipped over to cause the next domino to fall. This can lead to a chain reaction with thousands of dominoes falling over, and create some incredible designs.

Dominoes are also used in games of chance. Players accrue points for certain configurations or moves. The most popular type of domino game is a blocking or scoring game, where the object of play is to empty your opponent’s hand while blocking their ability to take another turn.

The earliest known use of the word domino is in the mid-18th century, when it was used for games that involved placing tiles edge to edge in a line. In these positional games, each player in turn placed a domino with matching ends on adjacent sides of the line. If the exposed pips totaled a specific number, then that number was recorded as the winning score.

These early sets were made of natural materials, such as bone or ivory or a dark hardwood, such as ebony, with contrasting black or white pips inlaid or painted. In the 19th century, manufacturers began producing domino sets out of wood, cardboard, and plastic. A large variety of sizes, shapes, and colors are available today.

Some people are skilled at creating intricate domino arrangements. A YouTube user named Hevesh, for example, has more than 2 million subscribers and creates stunning domino setups for movies, TV shows, and events—including a Guinness record-breaking circular design that featured 300,000 dominoes. Her largest creations can take several nail-biting minutes to fall.

Other kinds of domino games are based on the way that the pips on each side of the domino match up, or fit, with the corresponding pips on other tiles. When a double is played, for instance, the two matching ends must touch completely.

There are also many ways in which the dominoes can be arranged to form chains or other patterns. The way a set is laid out determines the shape of the chain that develops, and the rules of how the game is played.

The phrase domino effect is often used to describe something that starts with a small event but ultimately leads to larger and sometimes catastrophic consequences. It’s also a great term for the way that one small action can affect others, either positively or negatively. For example, if someone is angry at their boss, that anger may spread to other employees—or even to customers. That’s what happened at Domino’s Pizza when CEO Don Meij appeared on the show Undercover Boss. He went undercover to work at a Domino’s restaurant and saw firsthand how some of the company’s policies needed some tweaking. The changes he enacted included new leadership training programs, a relaxed dress code, and a better system for listening to employee feedback. As a result, Domino’s is now ranked among the Top Workplaces by the Detroit Free Press.

The Basics of Dominoes