In a game of domino, each player plays a tile so that it touches one end of a line of already-played tiles. The line can be a long, continuous row, or it may be a series of angular or circular patterns. Each domino is marked on both sides with a value from one to six dots (or spots). The value of a particular end of a line is called its rank or weight. The highest rank or weight wins the game. A domino with a higher value is also considered more “heavy” than a lower rank or a blank domino.
The most basic domino set consists of 28 tiles and is known as a double-six set. These tiles are shuffled and then each player draws seven. A player must draw a domino that is legal for the current game. Once a player has drawn his or her seven tiles, that player makes the first play by placing a domino in the line of play. The next player must then play a tile so that it touches one of the ends of the previous domino. This creates a chain that gradually increases in length.
As players continue to play their tiles, they build a line that is called the line of play or string. The open end of the last domino played must be facing up in order to prevent the tiles from falling off the table. The line of play can be joined either with the dominoes in a row, lengthwise, or across them, crosswise, so that they match.
Dominoes can be stacked in various ways to make structures such as towers, pyramids, and castles. Often, these structures are built for entertainment purposes such as domino shows, where builders compete to create the most spectacular domino effect or reaction before an audience of fans.
Thousands of dominoes can be carefully set up and positioned to tip over in a precisely controlled sequence. They are usually made from a plastic-based material, such as polymer clay or polystyrene foam. Some sets of dominoes, however, are traditional: they are made from bone or silver lip ocean pearl oyster shell (mother of pearl), ivory, or a dark wood such as ebony, with contrasting black or white pips. These are usually much heavier and more expensive than the sets made from polymer materials.
The fact that dominoes stand upright, resisting motion until a small nudge causes them to fall over, is analogous to the way that certain types of narratives work. When a storyline is outlined, it’s important to think of each plot beat as a domino that needs to be tipped over, one after the other.
When a domino is tipped over, it releases the potential energy stored within it to push on the next domino. Similarly, every plot beat in a novel has the potential to cause a domino effect—to tip over other characters and events, and to change the course of a storyline.