A domino is a small rectangular wood or plastic block that has one side bearing an arrangement of dots resembling those on dice and the other blank or identically patterned. A domino set generally contains 28 tiles. A player sets up a series of dominoes on the table and in turn plays a tile that either blocks an opposing tile or forms a particular total. A game may be won by the first person to reach a predetermined total or by the first player to cover all of the opponents’ numbers.

Dominos are used in a variety of games. Players can use a set to create curved lines, grids that form pictures when they fall, or 3D structures like towers and pyramids. Some people even build complex, aesthetically pleasing domino art. Lily Hevesh, a domino artist who has more than 2 million YouTube subscribers, enjoys planning out her creations before she begins setting them up. She makes test versions of each section and films them in slow motion so that she can make precise adjustments.

In her latest video, Hevesh plans out a huge domino track for a chess game. She starts by drawing the arrows that show the way that the dominoes will fall. Next, she lays out the pieces of the domino track on a piece of paper. She makes sure that the arrows are pointing in the right direction, and she also calculates how many dominoes will be needed for the track.

When Hevesh puts the pieces in place, she tests them out again to ensure that they work correctly. She demonstrates the process in her video and also includes tips for creating your own domino tracks.

Although domino is usually played by two or more people, it can also be used in single-player games. Some of these are adaptations of card games and were once popular in areas where religious proscriptions against playing cards did not apply. Others are positional games, where each player places a domino edge to edge against another in such a way that the adjacent faces either match each other or form some specified total.

Domino is also a common phrase, used to describe a chain reaction or a sequence of events that culminates in a major event. The concept is based on the fact that, like dominoes, even tiny, seemingly insignificant actions can have far-reaching consequences.

Domino theory is the name given to a hypothesis about international politics, stating that once one country introduces a policy that other countries will react to, it will lead to a series of domino-like events that cannot be stopped and that will cause a cascade of political change. The theory has not been proven and some experts have raised concerns that the model can be used to justify aggressive military action in the Middle East, a region where it has already been applied to some extent. Others, however, have cautioned that the theory is overblown and should be interpreted with a great deal of skepticism.