A domino is a thumbsized, rectangular block with one side blank and the other bearing from one to six dots (also called spots) in arrangements similar to those on dice. A set of 28 such dominoes forms a complete domino game. Most of the games played with dominoes involve matching the ends of the pieces or laying them down in lines and angular patterns. Like cards and dice, dominoes can be used to play many different types of games.

Despite their diminutive size, dominoes possess tremendous power, as demonstrated by the awe-inducing displays that are created at domino shows. In such events, domino builders line up hundreds and even thousands of dominoes in careful sequence, allowing them to topple with the gentle nudge of only one. The awe generated by these domino shows is an apt metaphor for the effect of a single decision or act on an entire situation.

To create these massive arrangements, domino artists use a variety of tools, including drill presses, radial arm saws, belt sanders, and welders. But there is one fundamental physical principle essential to their success: gravity. Stephen Morris, a physics professor at the University of Toronto, explains that standing a domino upright entails lifting it against the force of gravity. As a result, the domino stores potential energy, which is converted to kinetic energy as it falls, thus setting off the chain reaction that causes domino after domino to fall.

Domino is a great tool for writers to understand because it illustrates a crucial principle of storytelling: the chain reaction. If you want to have an impact on your readers, then you must plan ahead and consider all the ramifications of your actions. If you don’t plan your scenes carefully, then you will end up with scenes that do not advance the plot and instead merely fill in space. For example, if your heroine uncovers an important clue in the first scene, but the following scenes do not build on it, then your audience will probably be left confused or unengaged.

The domino effect is also a good metaphor for the way in which our behaviors and attitudes are connected to other people’s choices. For example, if someone decides to lose weight, they are likely to influence other people by their actions, encouraging them to adopt a healthier diet as well. Similarly, if you are a “pantser” writer who does not make detailed outlines of plot ahead of time, you will likely end up with scenes that do not build on each other and raise tension.

The same principle applies to our personal relationships. A positive relationship can have a powerful influence on those around you, motivating them to emulate your behavior and attitudes. A negative relationship, on the other hand, can have the opposite effect, causing others to distance themselves from you.