# How Dominoes Work

Dominoes are tiles whose ends display numbers from six down to none or blank. They are normally twice as long as they are wide, making them easy to re-stack after use. The values on either end, also known as the pips, can be used to form many different kinds of games. These include blocking and scoring games, where one player tries to stop the opponent from making a certain kind of play; and trick-taking games that were once popular in places with religious proscriptions against playing cards.

Lily Hevesh started creating mind-blowing domino setups as a child, and now she creates displays for movies, TV shows, and events—including an album launch for Katy Perry. She has worked on team projects involving 300,000 dominoes, and she helped set the record for the most dominoes toppled in a circular arrangement: 76,017. Her largest installations take several nail-biting minutes to fall.

Hevesh starts each project by considering the theme or purpose she wants to convey with her layout. Then she brainstorms images or words she might want to use and plans out how to arrange the dominoes. She may build a grid that forms pictures or walls, or she might set up 3-D structures like towers or pyramids.

She divides her fractions to determine how many dominoes she needs for a project, and she uses a ruler to draw her designs on the surface she’ll be using. She omits a few dominoes here and there—until she has the precise layout she wants. That way, if she or a teammate accidentally knocks over a portion of the installation, it won’t bring the entire arrangement crashing down.

As each domino is placed on the table, its potential energy converts to kinetic energy, and some of that kinetic energy is transmitted to the next domino. If that domino is a double, for example, the second tile will add its own double’s worth of potential energy, which helps to push it over as well. The process continues, from domino to domino, until the last one falls.

The game can be played with two or more players and is normally scored in a variety of ways. Typically, the losing players count all of the pips on the end tiles that remain in their hands at the end of a hand or a game and compare them to the winning players’ total number of pips. In some cases, the winning players count only the number of pips on the ending tiles that are not a double (e.g., a count of five at one end and three at the other results in a score of nine).

The simplest scoring method is to simply subtract the value of a single domino from the sum of the total pips on the end tiles left in each player’s hands. This scoring method is sometimes called “taking the pips” or “counting the pips.” Some games also have rules that vary from the simplest version of this rule, such as counting only one end of a double and adding that to the total of the other players’ scores.