A small rectangular wood or plastic block, marked with dots resembling those on dice, used in games to score points by laying them end to end. Each touched end must match either a number or blank side, or form some other specified total; if a player plays a domino that results in the exposed ends showing all numbers (or all blank sides) the player is given that total as his or her score. The most common domino sets contain 28 tiles; larger sets are available, however, and these are frequently used in competitions involving hundreds of dominoes or more.

Dominoes are generally arranged in groups called suits. Each suit contains one or more identical tiles, and each tile has a number on it which corresponds to its position in the set. Each domino also has a side displaying a color or symbol, often a crown or horseshoe. The number on the face of a domino is usually indicated by a series of spots, but other symbols may be used. Dominoes have a long history of use, dating back to the 18th century. They were first recorded in Italy and France, and were introduced into England toward the end of that period.

Most domino games involve the players forming chains of dominoes, with each domino positioned so that its ends match one another, or are part of an existing chain. A chain can be broken by placing a domino with the exposed end on a domino of an opposite color or by placing it so that its exposed end is adjacent to one showing the same colored symbol or number, or by playing a single domino that changes the sequence.

The most popular types of domino play are blocking and scoring games. Most games are designed to be played with a double six set, although larger sets exist, and these are often used for scoring games. Some of these larger sets contain more than 28 tiles, and some have extended edges that allow for a greater number of possible combinations of ends; these are typically known as double-nine or double-twelve sets.

When a domino is knocked over, its potential energy converts to kinetic energy, the energy of motion; some of this energy is passed on to the next domino, providing the push that causes it to fall. This process continues from domino to domino until the entire setup is overturned. Domino shows feature builders constructing mind-blowing domino constructions, sometimes using hundreds or even thousands of individual pieces.

Domino is a fun game, and it can serve as a useful metaphor for the way plot works in a novel. Whether you write your manuscript off the cuff or follow a meticulous outline, you must consider each scene and action in terms of how it might affect the events that come afterward. Keeping this “domino effect” in mind will help you to create a satisfying story that holds together well.