A domino is a small rectangular wood or plastic block, thumb-sized in size, with one end blank and the other bearing from one to six dots resembling those on dice. A complete set of dominoes consists of 28 such blocks, and each is marked with either numbers or pips; the number-marked ones are called “nobles” while the pips are called “remainders.” The earliest sets were merely painted, but today dominoes may be made of ivory, bone, silver lip ocean pearl oyster shell (mother of pearl), or a dark hardwood such as ebony. They can also be made of metal, ceramic clay, or even frosted glass. A domino set also includes a game board.

Dominoes are used to play a variety of games, the most common being the simple game of drawing tiles and arranging them in rows and columns with matching ends touching. The resulting chains of dominoes, referred to as a “domino chain,” are then scored by counting the number of dots on the exposed ends of each tile. The first tile played to a line of dominoes must touch both adjacent sides of the second tile, or it is counted as double. The rules of many games allow additional tiles to be placed on any of the open ends of a double, as long as all four adjoining tiles are connected by a full set of touching ends.

In addition to playing games, dominoes can be used for a wide variety of artistic and architectural purposes. They can be placed on a flat surface to form curved lines or grids that form pictures, stacked walls, and 3D structures such as towers and pyramids. They can also be arranged to create musical effects or to provide an exciting backdrop for dramatic performances, such as a domino-falling contest.

A domino artist who creates mind-blowing setups is Hevesh, who has designed and built hundreds of such displays. She says that the most important element of a successful setup is gravity, which pulls a falling domino toward Earth and causes it to nudge the next domino, and so on.

Hevesh’s work involves a lot of planning, and the final results can take several nail-biting minutes to fall. She follows a version of the engineering-design process to plan her projects, brainstorming images and words she might want to include in a layout. She then calculates how many pieces she will need to make a particular design, and draws arrows on a piece of paper that show the way that the dominoes will fall.

A large lineup of dominoes can be a spectacular sight to see, especially in a competition that features multiple builders. Thousands of dominoes are carefully laid out in a careful sequence, and then all they need is the nudge of just one to cause them to tumble in a spectacular display. Some of these setups are used to win a domino-falling contest, and others are part of theatrical performances such as a “domino theater.” Occasionally, the entire display will be destroyed during the course of the show in a dramatic sequence that adds to the excitement for audience members.