Dominoes, cousins to playing cards and the oldest known game pieces for a chain reaction, are used for many games and tests of skill. They can be played with just a single domino or in long lines that must be knocked over. Dominoes can even be shaped, cut, or painted to make them more interesting or functional for specific games.
Like the numbered squares on dice, each domino has a pattern of spots or “pips” that identify it. The other side of the domino is blank or similar in appearance to the pips, but is not marked. A domino’s value is determined by its number of pips on both sides. Most of the popular types of domino play involve placing a line of dominoes and then attempting to knock them over. Some dominoes are used for other purposes, including art projects and physics demonstrations.
Most dominoes are made of a durable material that can withstand the impact of being knocked over. However, some of the more artistic and decorative sets are made from natural materials such as bone, silver lip ocean pearl oyster shell (mother of pearl or MOP), ivory, or a dark hardwood such as ebony, with contrasting black or white pips. In addition to their aesthetic appeal, these natural materials can give a set a heavier feel and more durability than polymer dominoes.
The most common dominoes come in a double six set, with 28 tiles that are normally twice as long as they are wide. These are generally the only type of dominoes that most people have in their homes. Smaller sets of dominoes, and even individual tiles, are also available.
To begin a dominoes game, the first player places one of their dominoes on the edge of the table, matching one end to part of another tile. The other end of the domino should be placed parallel to or perpendicular to the line of dominoes being built. If the domino being played is a double, it may be placed cross-ways over the end of the line.
Typically, the number of dominoes placed on the table is limited to a maximum of two or three rows, depending on the rules of the game. When the game reaches a point where no players can continue, play stops. The winners are the players whose combined sum of the numbers on their remaining dominoes is the lowest.
Dominoes are a great example of the law of large numbers, which states that if a number is multiplied by itself, the result will be greater than the original number. This is also an important principle in science, and it can be seen in a variety of ways when studying the physical world. For example, if a large rock falls onto a smaller rock, the larger rock will move faster and potentially cause more damage because it has more mass. The same principle applies to a chain reaction, such as a domino effect.