##### How Dominoes Are Played

A domino is a small rectangular wood or plastic block that is marked on one face with an arrangement of dots resembling those on dice. These dots, called pips, are separated by a line or ridge, and the opposite side of each piece is blank or marked with a pattern identical to that of the pips. Dominoes are used in a variety of games that involve stacking them on end and then knocking them over. Dominoes are also used to create patterns and shapes, such as lines and curves, grids that form pictures when they fall, and 3D structures such as towers and pyramids.

When a player plays a domino, he or she positions it on the table so that one of its matching ends touches a previous tile that has already been played. The number that shows on the touching side is then added to the previous total of the chain. In the simplest game, each player places one domino on the table in turn, positioning it so that it is touching one end of a row of tiles that gradually increases in length as other players play their pieces. If a player places a domino that makes both ends of the previous row show the same number (normally a useful number to the player and distasteful to his or her opponents), he or she is said to have “stitched up” the ends.

As each domino is positioned and placed, it builds up a chain that develops into a snake-line shape according to the players’ whims and the limitations of the playing surface. The chain becomes more complicated when players choose to add doubles to the mix, which must be positioned so that the two matching sides of the tile are perpendicular to each other and touch fully. In addition, each new piece must be matched to the next by its arrangement of pips.

Most domino games are played with a set of 28 dominoes, although larger sets are available for players seeking to play long-form domino games. These large sets are often “extended” by adding more pips to the ends of some of the tiles, increasing the number of possible combinations of ends.

Dominoes are a popular toy for children, who enjoy stacking them on end and then pushing them over. As each domino falls, it transmits energy to the next domino in its line, which can then be pushed over as well. This gives rise to the expression, the domino effect, which describes a series of events that begin with one simple action but ultimately has much greater–and sometimes catastrophic–consequences.

When Hevesh, a master domino artist who creates intricate layouts, pushes over one of her creations, it’s a little like a domino rally in slow motion. Each domino has inertia, a tendency to resist movement, but all it takes is a slight nudge to transform some of that potential energy into kinetic energy and propel the domino over the rest. This energy travels through the domino chain to the next, and so on, until it finally crashes.