Domino is a game of stacking tiles. It has roots in Chinese civilization and can be played by two or more people. The game is usually played with a double-six domino set; however, a player can also play with a larger number of pieces, called an extended set.

The basic rules of domino are relatively simple and are similar to those of card games. The first player draws seven dominoes for his hand and begins play by playing any domino he wishes. In some variations, a player’s hand must include the highest-value domino, or “double-six.”

A double-six domino has six pips on each side of its ends. If two matching tiles have no pips, they are discarded. Similarly, if two non-matching tiles have no pips, they are also discarded.

Many traditional sets of dominoes have a line in the middle that divides them visually into two squares, called ends. Each end may have a number of spots, or “pips,” which determine the value of the tile; in most sets, the highest-value piece has six pips on each end. Some sets may have blank ends, which allow a tile to have no value at all; these are sometimes called wild tiles.

As a result, the total number of pips on a domino can range from six to none. The values of a single tile are usually described in terms of rank or weight, where a heavier tile has fewer pips than a lighter one.

While some people may be wary of using dominoes in a game, they are a popular toy for children and are often used to build complex designs. They can be stacked on top of each other to create long, vertical lines. When the dominoes are placed correctly, the first domino in the line will eventually tip over, causing the other dominoes to fall too.

The chain reaction that results from the dominoes’ falling is a great demonstration of how potential energy becomes kinetic energy. In this case, the potential energy of standing a domino upright is stored in it, and as it falls, some of that potential energy converts to kinetic energy, the energy of motion (see Converting Energy).

It’s this ability to change form that makes dominoes such an effective tool for illustrating the science of physics. Stephen Morris, a professor of physics at the University of Toronto, has studied the effect and explains why it works:

According to his research, when you pick up a domino and stand it upright, you are lifting it against the pull of gravity. This raises it against the force of gravity, which in turn stores some potential energy.

When the first domino falls, much of that stored potential energy is converted to kinetic energy, or the energy of motion. Some of this energy is transmitted to the next domino, providing the push that knocks it over.

A domino can be a metaphor for the way we make decisions. Whether it’s about what to write or what to share with the world, we should always keep a larger perspective in mind. It’s easy to get bogged down with details, but remembering that a single action can have a chain reaction can help you prioritize your ideas.