Domino — a flat, thumb-sized rectangular block the face of which may be either blank or bear from one to six pips or dots: 28 such pieces form a complete domino set. The word also refers to any of several games played with such tiles, usually by matching the ends and laying them down in straight or curved lines and angular patterns.

The art of creating spectacular domino setups is popular with children and adults alike, and even professional set designers have taken up the challenge. Lily Hevesh, for example, is a prolific domino artist with more than 2 million YouTube followers who has created stunning domino designs for movies and TV shows, including an album launch for Katy Perry. Hevesh’s intricately planned scenes often involve thousands of dominoes, which are carefully positioned and then set in motion with the flick of just one.

In the most basic of domino games, players take turns placing a tile onto the table, positioning it so that its end matches the end of another in the chain. The goal is to form a line of matching pairs of ends, which can then be used to score points. These chains can be simple, or the rules of the game can be more complex, as in the case of a Concentration variant that uses a double-six set.

When a domino is stood upright, it has potential energy (energy based on its position). As soon as one of the tiles in the line is displaced by another, however, much of that potential energy is converted to kinetic energy, which causes the rest of the dominoes in the lineup to fall. The force that knocks down a sequence of dominoes is called the Domino effect, and it’s incredibly powerful. University of Toronto physicist Stephen Morris once demonstrated this with a series of 13 dominoes, each smaller than a Tic Tac and so thin they needed to be set with tweezers.

The same forces that create the Domino effect are also at work in the act of writing, which, as a process, is reminiscent of setting up a series of dominoes in careful sequence. Whether we write our manuscripts by hand or use a computer, we’re always asking ourselves the same question: What happens next? The answer depends on how the scene works together, and understanding this principle is key to making our fiction feel real.

The domino principle is just one of the many techniques we can use to create realistic stories. We’ve looked at other methods like point of view, pacing, and characterization, but there’s one more thing to keep in mind: how our characters interact with each other. Just as the smallest nudge can bring about a whole series of domino reactions, each character must have a reason to be in the story and a way to connect with other characters. This will help readers understand why each person behaves the way they do, and why the story is compelling.