A domino is a small rectangular block of wood or plastic, marked on one end with dots (or pips) resembling those on dice. It is the basis of a family of games played by two or more players. Dominoes are usually arranged in a tiled arrangement called a domino table, and each player has a set of tiles. Each player must play a tile in such a way that it either forms part of an existing chain or adds to the total value of a series. When a domino is added to a chain, it must be adjacent to the tile that is its highest value (either a double-six or a double-blank).
A game of domino is won by the first player to form a completed line of dominoes across the bottom of the table. The number of points awarded to the winner is determined by the rules of the specific game. Typically, the pips on opposing tiles are counted, although some games allow the use of blanks instead of pips, and the number of sides on a domino may be considered as well (for example, a double-blank can be counted as zero or fourteen).
The most common type of domino has 28 tiles and is known as a double-nine set. It is possible to extend this basic set by introducing ends with higher numbers of pips, and larger sets have been made. Most games require only a minimum of 28, but some have maximum values of 55, 91, or 190.
Dominoes are most often used for positional games, where each player places a domino edge to edge against another so that the adjacent faces are identical or form some specified total. The lower value domino is called the base, and the upper one the apex. The apex is also the point of rotation for the domino, which can be rotated as needed to change the direction of the line of play.
Dominoes are a popular activity with children, and many children’s books contain dominoes as a device for telling stories. The most famous is probably “The Little Red Hen”, which describes how the hen used her eggs to start a domino effect that ended in a great roosters’ race. Similarly, the domino effect is an adage about how making one positive change will trigger other similar changes that are in turn will influence your life. For example, studies have shown that when people spend less time on sedentary leisure activities they will reduce their fat intake by default as a side-effect of their new behavior. The same principle can be applied to other aspects of our lives as well. As a book editor, I try to teach my clients that the best way to improve their writing is to think about each plot beat as if it were a domino that needed to be tipped over. It’s not easy, but it’s the best way to develop a novel that readers will want to finish reading.