Domino is a family of games that are played with rectangular plastic or cardboard tiles that have one or more dots on each end. Traditionally, domino sets consist of a number of tiles that are laid out in a line and then matched with each other by matching the pips on the open ends. Often, the pips on each end of a domino match in pairs. When all of the pips are lined up, the domino is considered complete and may be placed on the table or in a box for safekeeping until it can be used again. There are many different types of domino games, but most of them fit into one of four categories: bidding, blocking, scoring, and round games.

The power of a domino effect is often demonstrated when someone tips over a single unmoving domino, which then triggers a chain reaction that causes more and more of the pieces to fall down in a rhythmic cascade. But in reality, these unmoving dominoes have a lot of inertia and will resist motion unless an outside force is applied to them. In a 1983 experiment, University of British Columbia physicist Lorne Whitehead demonstrated that a single domino can knock over something one-and-a-half times its size.

In a similar manner, one traumatic event can have a domino effect on many areas of an individual’s life. An incident such as a workplace injury or a break-up can upset an otherwise stable balance of work, home, and family. In business, a poor performance review can cause an employee to leave, and a departure of key staff can negatively impact customer service and lead to an increase in sales calls or complaints.

Dominoes can be made from a variety of materials, including ivory, silver lip ocean pearl oyster shell (mother of pearl), bone, and wood such as ebony. In some cases, these natural materials are preferred by players for their luster and tactile quality. They also have a more novel look than modern polymer dominoes, although they are often much more expensive.

When playing domino, each player draws a hand of tiles for the game. The tiles are then arranged on the table, forming a line that is sometimes called the line of play, layout, or string. This arrangement of tiles is determined by the rules of the game being played, and it is important to keep the line of play as neat as possible to prevent dominoes from falling off the edge of the table.

Some games allow players to purchase additional dominoes from the stock, which is placed face down on the table. When a player discovers that his hand contains more than he is allowed to have, he must draw the excess tiles and place them in his own hand before playing any of them. Alternatively, he may be permitted to pass or bye a tile instead. This is generally agreed upon by the players before the game begins.