Dice - Construction

Construction

Common dice are small cubes most commonly 1.6 cm across, whose faces are numbered from one to six, usually by patterns of round dots called pips. (While the use of Hindu-Arabic numerals is occasionally seen, such as in the game Pop-O-Matic Trouble, the ambigrammatic properties of the digits (for instance, 6 can look like a 9 upside down) make such dice uncommon.) Traditionally, opposite sides of a die add up to seven, implying that the 1, 2 and 3 faces share a vertex; these faces may be placed clockwise or counterclockwise about this vertex. If the 1, 2 and 3 faces run counterclockwise, the die is called right-handed and vice versa. Western dice are normally right-handed and Chinese dice are normally left-handed.

The pips on dice are arranged in specific patterns as shown in the picture to the left. Asian style dice bear similar patterns to Western ones, but the pips are closer to the centre of the face; the one's pip is larger than the others, with that and the four's pips coloured red. In some older sets, the "one" pip is a colorless depression. It is suggested that an entirely black and white color combination on the one's and four's sides would be unlucky; red, a lucky color in Chinese culture, would counteract this. The word for four in Chinese is a homophone of the word for death and is considered unlucky; it is probable that red fours are of Indian origin.

The result of a die roll is determined by the way it is thrown, according to the laws of classical mechanics; they are made random by uncertainty due to factors like movements in the thrower's hand. Thus, they are a type of hardware random number generator. Perhaps to militate against concerns that the pips on the faces of certain styles of dice cause a small bias, casinos use dice with flush markings.

Dice are thrown, singly or in groups, from the hand or from a container designed for this (such as a dice cup), onto a flat surface; the face of the die that is uppermost when it comes to rest provides the value of the throw. A typical dice game today is craps, where two dice are thrown at a time and wagers are made on the total value of the two dice. Dice are frequently used to randomize moves in board games, usually by deciding the distance through which a piece will move along the board; examples of this are backgammon and Monopoly.

Clones of board games must use computer generated dice; the values are usually determined by a pseudorandom number generator, then displayed as a visual representation of a die. The reverse is also possible, with bar coded dice shuffling as a source of true random data for computers.