Domino is a game played with small rectangular blocks of wood or similar material, each bearing from one to six dots or “pips” on each end. A domino set contains 28 such pieces and is used to play a variety of games. The term is also applied to the overall pattern of domino tiles laid down in a line or other shape.

When a domino is knocked over, its energy is transferred to the next domino on the line, which then provides the push it needs to fall. This cycle continues until all of the dominoes have fallen in a domino chain. As the chains grow, they can become elaborate, forming a complex puzzle with many layers of interconnecting lines.

Lily Hevesh has been playing with dominoes since she was 9 years old, when her grandparents gave her a classic 28-piece set. She is now a professional domino artist who creates mind-blowing designs for movies, TV shows, and events—including a concert for pop star Katy Perry. Hevesh is careful to design each domino setup with science in mind.

According to physics, each domino has potential energy, or stored energy based on its position. When a domino is stood upright, it lifts against the pull of gravity and stores that energy in its structure. When the domino falls, most of that energy is converted to kinetic energy, or energy of motion, and is transmitted to the next domino on the line, providing the necessary push to cause it to fall. The rest of the energy is absorbed by the domino’s impact with the ground or other surface, and is lost.

The way a domino is placed also adds to the entertainment value of the game. Each tile must be played to a tile that is already on the layout, and the matching ends of the tiles must be touching. When a tile is played to an open end, it must be placed perpendicular to that end (unless the tile is a double).

In addition to the usual blocking and scoring games, there are also domino variants that resemble card games or other types of strategy games. In the latter, the dominoes are played to a board and are placed either horizontally or vertically, with each piece connecting to other adjacent pieces. The resulting pattern of tiles develops into a snake-line sequence that is played out on the table.

A great book plot requires a complex series of interactions between characters—and the domino effect can help make those interactions come to life on the page. Whether you’re writing off the cuff or using a meticulous outline, understanding how domino works can help you craft an engaging story.