Dominoes are rectangular blocks of molded clay or plastic, bearing an arrangement of spots, or “pips,” on one side and blank or identically patterned on the other. The pips, which are also found on dice, allow players to identify each domino from the next. Dominoes come in different sizes and colors, and are used to play a variety of games. The domino game is a popular pastime for people of all ages, and it fosters social interaction among participants. In fact, the domino game has become a symbol of unity and cooperation across societies, transcending linguistic and geographic barriers.
In the modern sense of the word, domino is a game of skill and strategy that involves placing a series of matching dominoes edge to edge in order to form a specified total. The rules of the game vary by country, but most involve a number of steps to be completed before a player can make another move. In addition to blocking and scoring, there are other types of games that may be played with a domino set. These include solitaire games, such as Concentration, and trick-taking games that are adaptations of card games.
When a player draws a domino from the stock, the game begins. The player must then match the tile to the other players’ hands according to the rules of the particular game being played. If the tile drawn is a double, it must be joined with the line of play (lengthwise) while singles are played across the line.
After the introductory sequence of tiles has been played, the players will sometimes be left with more than they need for their hand. If this occurs, the excess tiles are referred to as an overdraw. When the player to the right of an overdraw discovers this, he takes the extra tiles from that hand without looking at them, and returns them to the stock before continuing his turn.
During the course of a game, it is possible that no other players will be able to make a play. In this case, the players’ hands are said to be blocked and the game ends. There are exceptions, however. Some games have rules allowing players to “buy” any extra tiles in the stock that they need for their hand.
The power of dominoes is also demonstrated by the way that one falling domino can trigger the collapse of a much larger stack. This phenomenon is referred to as the domino effect, and it occurs because each domino has potential energy, or the energy that it would have had if it were still standing. When the first domino falls, some of this energy is converted to kinetic energy, which provides the push necessary to knock over subsequent dominoes.
The pips on dominoes are typically arranged in sets of seven, although some sets have more or less than seven. These varying numbers increase the number of possible combinations of ends and thus of dominoes. Larger sets are often “extended” by introducing additional pips on the ends of existing dominoes, adding up to six, twelve, fifteen, and even double-nine, though these extended sets are rarely used in actual play.