Dominos standing upright have gravitational potential energy that is freed when they fall down. Each one also gets some extra energy from pushing over the next one.
A set of 28 dominoes are shuffled and formed into a stock or boneyard. Each player draws the number of tiles he is permitted to take for his hand according to the rules of the particular game.
Rules
Depending on the game, there are many different rules for domino. Most games have one or more players who take turns attempting to get rid of their dominoes. The first player to do so wins the round. The winning player adds the value of the dominoes still in their opponent’s hands to their score.
In most domino games, a domino must be joined to an adjacent domino that has matching ends. This is called a “train.” A train must continue until it has reached the other side of the table, or a player calls “Muggins.” This indicates that all adjacent dominoes have been played and that the train is no longer possible.
After the tiles are shuffled, each player draws seven dominoes for his hand. Typically, the player with the heaviest double makes the first play of the game. The player then takes turns placing dominoes in a line and joining them to matching ends.
Variations
There are many variations of domino, each with different rules and scoring. Some involve extending the line of play by connecting a tile from your hand to one end of those already played. Others, like Bendomino or Matador, have unusual rules for matching ends.
Depending on the game, the object may be to block the other players from playing or to get the lowest score after three rounds. Some games also have specific pips to count, such as muggins, where the aim is to make the sum of the open-end pips on a tile match those on an existing one.
The word domino has several meanings, but the most common refers to a set of 28 small oblong pieces marked with 0-6 spots on each side. These are used to play positional games, in which players place one domino edge to edge against another in order to form a line that matches some specified value.
Materials
Dominos are small rectangular blocks of rigid material. They are characterized by one end having more dots than the other and are blank or identically patterned on the other. They are sometimes referred to as bones, pieces, men, or cards and are used in games of chance and skill. The first Western dominoes of the 18th century were made from animal bone (and ivory for wealthy players) and had black spots drilled into the bone and inlaid with thin pieces of ebony. Each domino represents a different combination of the numbers of two dice throws and therefore has one big end and one small end.
Among the most popular domino brands are those made by Maria Lamping and Bulk Dominoes. They are 4.8 x 2.4 x 0.75 cm (1.89 x 0.94 x 0.0.3 in) and come in a wide range of colors. They are ideal for building lines and fields as well as structures. The only downside is that the debossed Mr. Domino logo on every piece leads to unexpected light reflections and is distracting for many builders.
Scoring
Dominoes are scored by counting the value of each end, or pips. A domino is said to have “weight” or a higher rank if it has more pips than a smaller domino.
A round ends when all players have dominoes in their hands and can no longer make a play. The winning player (or team) then collects points based on the dominoes in the opponents hands.
Each player is allowed 15 seconds to play a domino. If a domino is pulled from the boneyard and not played in that time it is considered exposed and must be placed on the proper end before the next play. If a player notices an exposed domino they must call a UDL Official to resolve the situation.
A scoring variation called Muggins allows players to score off the ends of doubles that have been exposed sideways. One point is scored for each multiple of five in the ends. Blanks are not counted.