Dominoes are a type of tile game that has become popular in many countries. They are a flat rectangle with a pattern of alternating colored spots (called pips) on one side, and blank or identically patterned faces on the other. Each domino has a total of twenty-four spots—ten on each of four corners, and six on the vertical center line. The tiles are made of a hard material such as bone, ebony, or ivory. They are arranged in sets and played according to the rules of the game. Some of the games are based on blocking and scoring, while others have a different character, such as solitaire or trick-taking. A very large number of games may be played with dominoes, but most fall into four categories: bidding games, blocking and scoring games, drawing and passing games, and round or chasing games.
A player’s seat at the table in a game with three or more players is determined by lot. After the dominoes are shuffled, each player draws a hand of dominoes for that particular game. The player with the highest drawing takes the first seat at the table, then the next highest, and so on. In some games, a player who cannot play a domino may buy the highest hand of another player by paying for it in cash or points.
The dominoes are then placed on the table in a layout, string, or line of play. A tile may be played in any direction on a line of other tiles, but the two matching ends of the domino must touch fully to form a chain. A chain is not complete until the last domino has been placed squarely on top of the lowest double, forming a neat, snake-like arrangement.
Depending on the game, the line of play may be a single row or an infinite grid. The players may also arrange the dominoes in curved lines, into patterns that form pictures or letters, or in 3D structures like towers and pyramids. This sort of domino art is called a domino track or display, and it can add an aesthetic element to the playing surface.
In addition to the rules of the individual games, there are a few general rules that are necessary for proper domino play. For example, the players must reshuffle their hands before each game and thoroughly mix them by moving them with their hands. The player who does the shuffling for a particular game may be the same person each time or may alternate between players.
The heaviest double begins play in most games, although some allow the winner of the last game to open the game. If there are no players who have a domino with the heaviest value, each player must draw new hands. The players must continue to draw new hands until they find a domino with the desired value, or until they reach a point at which no further play is possible.