Domino, also called dominoes or domino blocks, are small flat rectangular blocks of hard material that are used as gaming pieces. The word domino is derived from the Latin dominum, meaning “flip.” Each domino has an identity-bearing face, usually marked with an arrangement of spots or pips (see image) like those on a die, and a blank or identically patterned opposite face. The domino is a game object that has no intrinsic value, although some games do use scoring systems and rules for play. The most popular types of domino games can be grouped into four categories: bidding, blocking, scoring, and round.
The first rule of domino is to always play your tile before the opponent plays his or hers. A player who fails to observe this simple rule may forfeit the game, or, in some games, his or her turn. In addition, a player must play his or her tiles in the order prescribed by the rules of the game, which differ from one to another. Generally, the rules state that the player holding the highest double or the highest single begins play. Alternatively, the player with the heaviest tile may begin play. In a tie, the players draw new hands to break the tie.
After a player has played his or her tile, he or she must announce the outcome of the play to the opponents. This is done by “knocking,” or rapping, on the table, which signals to the opposing players that the player has a valid move. Then the opposing players may choose to play a domino or to knock again to continue the chain reaction.
Most domino sets consist of 91 tiles, with each piece bearing the same number of pips as a die on one side and a blank or identically patterned face on the other. The most common extended sets add three more pips to each end of the domino, thus increasing the number of possible combinations of ends and pieces. There are several hundred different variations of domino games that can be played with these extended sets.
While some of these variants are competitive, others require teamwork and strategic thinking. Many people, however, are most interested in domino shows, where builders construct intricate and imaginative setups that ultimately topple with the nudge of only one domino.
Whether we’re discussing domino games, building structures with them, or plotting stories, the idea that one event can set off a sequence of events is an essential component of narrative. When composing a novel, for example, this is known as the domino effect. The same principle applies to our daily lives, as it’s quite possible that the little things we do today could lead to unexpected consequences in the future.