Dominoes are rectangular tiles, similar to playing cards or dice, that can be stacked together in long lines. When one domino is tipped, it causes the next to tip, and so on until all the pieces are in motion. The phenomenon has inspired the term "domino effect," which describes how one action has far-reaching consequences.A domino can also be a metaphor for change. For example, if you begin to make your bed each day, it will eventually lead to the habit of keeping your house clean. Jennifer Dukes Lee, a writer who has written about her experience with the Domino Effect, says that when she started making her bed each day it was a small commitment to the idea that she is "the kind of person who keeps her home tidy." This new self-image drove her to continue the behavior and expand it to other areas of her life.In business, the Domino Effect is often used to describe a chain reaction that results in a domino-like pattern of successes and failures. Using this concept, managers can create a strategy for building new behaviors that will lead to better results. For example, when starting a new habit, it is important to focus on the first step and not worry about how it will affect the whole picture. If you try to change too many things at once, you are more likely to fail.Physicist Stephen Morris, who studies the physics of falling dominoes, suggests that the success of a Domino Effect depends on gravity. When a domino is standing upright, it stores potential energy. As soon as that domino falls, most of that potential energy is converted to kinetic energy. This energy pushes the next domino toward Earth, causing it to topple and start the chain reaction.When you play Dominoes, it is important to understand the rules of the game. Most sets of dominoes feature two suits of numbers, each containing eight squares that are marked with arrangements of dots, called pips. Some of these pips are blank, and these are referred to as the zero suit. The most common domino set contains 28 dominoes, but larger sets exist for playing longer games.The first domino set was invented in France in the late 1700s, but it is not known how the game was played at that time. By the late 1800s, dominoes were popular in England and America, where it was often referred to as pupai. The English version of the game differed from the Chinese game in that the European dominoes did not contain the military-civilian suit distinctions and had fewer blank faces. In addition, the dominoes did not have a symmetrical shape like those of the Chinese dominoes. This difference made it more difficult to use the tiles in an exact symmetrical arrangement. The symmetry of the dominoes in Chinese games allowed for more complex layouts and a higher level of skill.