<P> The result of a die roll is determined by the way it is thrown, according to the laws of classical mechanics . A die roll is made random by uncertainty in minor factors such as tiny movements in the thrower's hand; They are thus a crude form of hardware random number generator . Perhaps to mitigate against concerns that the pips on the faces of certain styles of dice cause a small bias, casinos use precision dice with flush markings . </P> <P> Common dice are small cubes most commonly 1.6 cm (0.63 in) 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 dice are less common .) </P> <P> Opposite sides of a modern die traditionally add up to seven, implying that the 1, 2 and 3 faces share a vertex . The faces of a die 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 if those faces run clockwise, the die is called "left - handed". Western dice are normally right - handed, and Chinese dice are normally left - handed . </P> <P> The pips on dice are arranged in specific patterns as shown . Asian style dice bear similar patterns to Western ones, but the pips are closer to the center of the face; in addition, the pips are differently sized on Asian style dice, and the pips are colored red on the 1 and 4 sides . One possible explanation is that red fours are of Indian origin . In some older sets, the "one" pip is a colorless depression . </P>

What do opposite sides of a dice add up to