In common usage, randomness is the apparent or actual lack of definite pattern or predictability in information. A random sequence of events, symbols or steps often has no order and does not follow an intelligible pattern or combination. Individual random events are, by definition, unpredictable, but if there is a known probability distribution, the frequency of different outcomes over repeated events is predictable. For example, when throwing two dice, the outcome of any particular roll is unpredictable, but a sum of 7 will tend to occur twice as often as 4. In this view, randomness is not haphazardness; it is a measure of uncertainty of an outcome. Randomness applies to concepts of chance, probability, and information entropy.
Ancient fresco of dice players in Pompei
The ball in a roulette can be used as a source of apparent randomness, because its behavior is very sensitive to the initial conditions.
Dice are small, throwable objects with marked sides that can rest in multiple positions. They are used for generating random values, commonly as part of tabletop games, including dice games, board games, role-playing games, and games of chance.
Four traditional dice showing all six different sides.
Composite image of all sides of a 12 mm (1⁄2 in) Roman die, found in Leicestershire, England
Roman wall painting showing two dice-players, Pompeii, 1st century
Knucklebones die, made of soapstone
