Dominos are small rectangular wood or plastic blocks marked with dots resembling those on dice. They are stacked on one another, face up or down, to form lines or patterns that fall when they are knocked over. The most basic domino set is the double-6 set, which has 28 tiles. It’s the basis for most games played with dominoes, though rules vary widely. The most common extended sets are the double-9, double-12 and double-15 sets, which have 91, 136, and 190 tiles respectively.

Most domino games involve a number of players who take turns placing tiles in a line. This line is called a string or layout, and it’s important that the tiles fit together properly to prevent tumbling and to allow for the development of complex designs. A tile played to a line of dominoes must match the open end of the previous tile (or tiles) and can be placed anywhere in the chain, except on top of a double.

The way a domino is positioned on the layout also plays an important role in scoring. For example, a double is always placed crossing-ways across the string. Similarly, the number of dominoes left in the losers’ hands at the end of a hand or game is generally calculated by counting the number of pips on the dominoes and adding them to the winner’s score. The number of pips on a single domino, however, is only counted once.

Dominoes can be used to create many different types of artwork, from straight and curved lines to grids that form pictures when they fall to 3D structures like towers and pyramids. In addition, the symmetry of dominoes makes them an ideal tool for creating intricate geometric shapes.

For many people, the best way to enjoy domino is simply playing the game with family and friends. The game’s simple rules and straightforward strategy make it suitable for all ages, from children to grandparents.

By the time Lily Hevesh was 10, she was building elaborate domino installations. She now works as a professional, creating spectacular setups for film and TV shows, as well as events like the album launch of pop star Katy Perry. Her YouTube channel, Hevesh5, has more than 2 million subscribers.

Using the principles of fractions, Hevesh determines the number and placement of dominoes for each installation she builds. For example, for a project that requires dominoes 24 inches long, she divides the length of the layout into several equal parts to calculate how many of each type she needs to build the desired design. This process helps her avoid big accidental topples and ensure that the layout is built with a consistent pattern. It also makes it easier for her to keep track of the total amount of dominoes needed for a project. For the most elaborate projects, she sometimes omits dominoes until the last minute to minimize the risk of them falling over. This helps to prevent the dominoes from accumulating too much dust and becoming brittle.