Domino is a game in which players make plays, or sequences of tiles, that cause other tiles to fall. The first player to do so wins the game, and there are a wide variety of games with different rules. Regardless of the exact rules used in a particular domino game, most of them are similar and fall into four categories: bidding games, blocking games, scoring games, and layout games.
A domino is a small, thumb-sized rectangular block bearing from one to six pips or dots on each of its faces, which may be blank or identically patterned on both sides. A complete set of dominoes contains 28 such tiles. Most dominoes are made of ivory, silver lip ocean pearl oyster shell (mother of pearl), bone or a dark hardwood such as ebony with contrasting black or white pips. However, sets have also been made of marble, granite, soapstone, other woods, metals and even ceramic clay.
Each domino has a unique number of pips or dots, which differentiates it from other tiles in the same set. A domino that has a full complement of pips, or is “complete,” belongs to a suit with the same number of pips. The most common sets of dominoes commercially available have a maximum of twelve pips on each end and contain 91 tiles. Larger sets with more pips on each end are possible, but rare and costly.
The game of domino can be played with just two or more players. The more players that are added, the larger a domino game can become and the more challenging it is to score points.
Before a game begins, the players draw tiles from the stock according to the rules of the particular domino being played. The player who draws the highest double, or a double with a matching number of pips on both ends, starts play by placing it down in front of him. The other players then draw and place their tiles according to the rules of the specific game.
Some dominoes, called spinners, can be played on all four of their sides, and are particularly useful for building a chain reaction. In some games, every tile played must be a spinner, or all of the doubles in the line of play must be spinners. This adds to the complexity of some domino games, and in others it is considered a bonus.
Most domino games involve forming a line of tiles as the players make their plays. This line of tiles is called the line of play, and there are basic instructions for playing it listed here under Line of Play. In many cases, a player will be playing out of turn when his tiles are not joined to the line of play or when he makes a mistake in placing his tiles. These misplays must stand unless the player can correct them before the next player plays. In some games, a player may “bye” (take a previously unused tile from the stock), but this is usually only allowed at the start of the game or when the player has reached his goal for the game.