Domino is a game in which small rectangular blocks with anywhere from one to six dots are matched together to form lines or angular patterns. They are knocked over and scored by a player. The game is named after its most famous set of rules, but there are many variations and rules. The word domino itself comes from the Latin dominus, meaning “lord” or “master.” The phrase is also used to describe a person who is able to think two moves ahead.

The most basic Western domino games are block-and-draw, with players drawing for the lead and then placing pieces in a row called the boneyard (or, in the United States, the stock). A player scores points by laying tiles end to end. Each touching end must match a tile already played (one’s touch ones, two’s touch two’s, etc.) and the sum of the pips on both ends must be a multiple of five. Dominoes with one side of six pips are often called double-sixes; they are considered to be the “heaviest” dominoes.

A domino’s identifying marks are typically arranged in the shape of Arabic numerals, although some sets have a line or ridge to divide the identity-bearing face visually into squares bearing either pips or blank. The number of pips on each side is the domino’s value, and the total is usually expressed as an integer, such as 6 or 12, although some variants use different numbers. A domino that has no pips at all is said to be a double-blank.

In addition to straight and curved lines, dominoes can be placed in three-dimensional structures such as towers or pyramids. When standing upright, they can create an intricate and aesthetically pleasing display. Dominoes can also be placed in a grid, forming patterns that can be interpreted as pictures or even a house.

Some of these domino-shaped creations are made for artistic purposes, such as creating a picture or a word or a word puzzle, while others are designed to be functional. For example, a child’s domino set could be used to teach counting, or a set of oversized dominoes could be used as a form of outdoor art.

While some people play domino for entertainment, other people use the game to develop strategy and thinking skills. For example, a teacher might introduce an activity where students must figure out the best way to get their classmates to complete a domino chain without getting a single domino out of place. In this type of activity, the teacher might ask the students to draw an outline on a piece of paper and then add dominoes to fill in the outline with the right information.

In some countries, school districts and private schools have incorporated domino-themed activities into the curriculum. These might include a class on the history of the game and its development, as well as lessons in strategy, thinking ahead, and the chain reaction. These lessons are meant to help students learn that one action can affect another, just as the first domino in a chain reaction can knock down hundreds or thousands of others.