# How Dominoes Are Played

Domino, a game of strategy and skill played with rectangular tiles, has captivated people around the world for centuries. Its simplicity and elegance appeal to both young and old, male and female, from all backgrounds and cultures. Dominoes can be used in many ways and in a variety of games, from simple counting-based exercises to complex strategies for scoring points. There are many variations to the basic domino set, but almost all the most popular games fall into one of four categories: blocking games, scoring games, round games, or combination games.

Each player takes turns playing a domino onto the table positioning it so that it touches one end of an existing chain of dominoes and leaves the other end free to be played upon. The resulting line is called the layout, string, or line of play. If a domino cannot be played, the player “knocks,” or raps the table, and play passes to the next player. The winner is the player whose total sum of all the spots on his or her remaining dominoes is the least.

When a domino is played, its open end joins with the open ends of adjacent dominoes and a number shows on the face of each adjacent domino. The number on each domino is the count of the current line of play, which gradually increases in length as more and more tiles are added to the chain. If a player plays a domino such that both ends of the chain show the same number, then that tile is considered to be a spinner and may not be played until the next turn.

A domino has the potential to move as soon as it is pushed, but it doesn’t move unless there is enough energy to overcome inertia. The energy needed to push a domino depends on how large it is and its position in the chain, but a small nudge is sufficient to push it past its tipping point. Then, like a firing neuron, the domino’s pulse travels down the line of dominoes.

Occasionally, players draw additional tiles from the stock and add them to their hand. The number of tiles drawn is determined by the rules of the specific game being played. In addition, in some games byeing is allowed, whereby a player draws tiles from the boneyard that he or she is permitted to take by virtue of the rules of that particular game. The player then places these tiles in front of himself so that the other players can’t see their pips. In the 1977 Frost/Nixon interviews, Richard Nixon defended his administration’s destabilization of the Allende government in Chile on domino theory grounds. He asserted that a Communist Chile and Cuba would create a “red sandwich” that the United States could not allow to form. This assertion was later resurrected by the Reagan administration to justify the U.S. invasion of Central America in the 1980s.