Domino is a game played with a set of rectangular wood or plastic blocks, each marked with a pattern of dots that resemble those on dice. Each domino has two sides; one side is blank and the other shows a number ranging from 1 to 10. Players turn over their tiles, playing them so that they touch one another on the edges. The resulting chain, called the line of play, gradually increases in length. Play continues until one player chips out, announcing that they are ready to pass the turn. Depending on the rules, other players may then chip out or continue to play their tiles.

Dominoes are most commonly used for positional games, where a domino is placed edge to edge against an existing tile so that the adjacent faces match each other (one’s touching one’s, two’s touching two’s, etc.). This type of domino, sometimes referred to as a “positional” or “linear,” is the basis for many popular games.

When a domino is placed, it has potential energy, or stored energy based on its position. When it is stood upright, the force of gravity acts on the domino and causes it to lean slightly toward its opponent. The resulting momentum, or kinetic energy, is transferred from the top of one domino to the next, which in turn receives that energy and is pushed slightly forward by it. This creates a domino chain reaction that causes the entire row of tiles to topple.

Each player draws the number of tiles permitted to them by the rules of the particular game. The player with the heaviest tile (in the case of a double, the one with the most dots on one end) then makes the first play. He or she may also play a double on the end of a line of dominoes that has already been built, depending on the rules.

After all the players have made their plays, a line of dominoes is formed on the table. This line of play may be joined in two ways, either with the line of play, which is a row of dominoes played end to end; or with a domino “spiner,” which must be played crosswise on the line of play. Depending on the game, doubles are played either crosswise or lengthwise; singles, usually only in the case of a spinner, must be played lengthwise. Dominoes are then scored according to the rules of the game.