Dice roll

Dice rolls are a type of notation to explain probability and range. The system for simulating randomness is taken from tabletop role-playing games, Dungeons and Dragons being a commonly known example, which has players roll multiple dice of varying face counts to decide outcomes. Dice rolls are an integral part of the game, being used in determining factors such as whether an attack hits and how much damage it deals.

Notation

 * The notation for dice is $$(n)d(f)$$, where $$n$$ is the number of dice and $$f$$ is the number of faces.
 * For example: 2d6 means outcome is determined by two (2) dice (d) that are six-sided (6).
 * The lowest output is $$n$$ and the highest output is $$n \times f$$; a 2d6 will roll between 2 (1+1) and 12 (6+6) and a 5d9 between 5 (1+1+1+1+1) and 45 (9+9+9+9+9).
 * Any prior numbers are multipliers: 42d2 means a base damage of 4 is multiplied by the 2d2 output.
 * Any following addition is done finally: 2d2+1 means 2d2 is rolled and then the result receives +1.

Example
A melee attack uses multiple dice rolls to determine outcome: