A domino is a small rectangular wooden or plastic block bearing one or more dots resembling those on dice. Traditionally, dominoes are set on end in long lines so that when the first tile topples, it causes the others to fall in a sequence known as the Domino Effect. Dominos can be used for games of skill or chance, and they can be decorated or sculpted into 3D structures such as towers or pyramids. The most common commercially available set of dominoes contains 28 tiles, though larger sets exist for play with many more players or to create longer chains. There are a wide variety of domino games, which can be divided into two categories: blocking games and scoring games.

The simplest domino game involves playing a single player against an opponent. Each player draws seven tiles, and begins by placing a tile on the table touching both ends of another domino (which must have the same number showing on both). This starts a chain of dominoes that develops into snake-lines depending upon the rules of the game and the skill of the players. The first player to place a domino of this type wins the game.

In a variation of this basic game, players may be required to play a certain number of tiles before their opponent does. Then the next player plays a domino touching only one end of a previous tile. If the next player cannot find a matching domino in his or her hand, that player must draw additional tiles from the boneyard until he or she finds one that can be played. This process is repeated until the player has placed all of his or her tiles or both opponents have played all of their tiles.

Larger dominoes are often arranged in circular formations, with special blockages or “firebreaks” at regular distances to prevent a section of the arrangement from undoing a larger portion of the system. The most complex domino displays are designed to be viewed from above, and can be quite stunning.

Dominoes can also be used to make a “domino art” that can be displayed on walls, floors or tables. Some artists have created curved lines, grids that form pictures when the dominoes fall, or 3D structures such as towers and pyramids. Some of these arrangements are accompanied by music to add to the entertainment value.

In fiction writing, the concept of the Domino Effect can be applied to scenes in a story. Like a domino in a set, each scene has to interact with the scene that comes before it to raise tension or introduce new information or arguments. If the scene isn’t relevant to the story or doesn’t advance the plot in some way, it may be considered an out-of-place domino. Consequently, the use of an outline or a writing program such as Scrivener can help writers avoid creating unnecessary or repetitive domino scenes. Likewise, for pantsers, who don’t write out full outlines of their stories before beginning to write, some simple scene dominoes can be helpful for keeping the action flowing.