A domino is a type of rectangular tile, or sometimes a card, that is used in various games. They are usually made of wood, ivory, or bone. One side is marked with spots, and the other is blank. Often, they are lined up in rows. However, they are also played by toppling them down.

Dominoes are often used as game pieces for various games, including trick taking, solitaire, and layout games. The first domino games are believed to have originated in Italy in the 18th century, and the games were introduced to France, Austria, and England during the mid-18th century.

Traditionally, European domino sets have been made of dark hardwoods, such as ebony and ivory. In addition, they are typically marked with a line in the center and pips, or arrangement of spots, on each end. These pips correspond to the suits of each tile, which are either threes, sixes, or nines.

As with dice, each tile in a domino set is unique. This allows players to make a variety of different combinations. There are also doubles, which serve as spinners. Unlike dice, which have a single face, Chinese dominoes are made with two faces.

Dominoes are also known as bones or tickets. Many children prefer to play with them as toys. They are commonly stacked on end, making it possible for them to be pushed or knocked down in long rows.

Some of the most popular domino games include the five-up and Tien Gow games. To play, each player draws seven tiles from a stock. Each tile has a different color, but a player can see all of his or her own tiles as well as the value of the tiles of opponents. Players then place the dominos edge to edge against each other. If one of the tiles falls, the next will fall, until the course has been completed.

There are also games in which dominos are used, such as Che Deng, Pai Gow, and Tien Gow. During the seventeenth century, the game was already being played in China. Unlike European dominoes, which have no pips or suit distinctions, Chinese dominoes are marked with the corresponding number of spots on each side.

Although they are used in many different games, the most common domino games are those where players score points for their efforts. Typically, the goal is to make a row of dominoes fall down, and when the last one in the row is tipped over, the next domino will tip over, causing the previous domino to fall down.

Dominoes are also used for studying nerve cells and neurons. Using a domino set for analysis, researchers can study nerve cell behavior by dividing each domino into four sections, which represent the four possible faces of two thrown dice.

There are several types of dominos, with the most basic variant requiring a double-six set. There are also variations that have no pips, or that use Arabic numerals instead of pips.