Games::Dice simulates die rolls. It uses a function-oriented (not
object-oriented) interface. No functions are exported by default. At present,
there are two functions which are exportable: roll and roll_array. The latter is
used internally by roll, but can also be exported by itself.

The number and type of dice to roll is given in a style which should be familiar
to players of popular role-playing games: adb[+-*/b]c. a is optional and
defaults to 1; it gives the number of dice to roll. b indicates the number of
sides to each die; the most common, cube-shaped die is thus a d6. % can be used
instead of 100 for b; hence, rolling 2d% and 2d100 is equivalent. If F is used
for b fudge dice are used, which either results in -1, 0 or 1. roll simulates a
rolls of b-sided dice and adds together the results. The optional end,
consisting of one of +-*/b and a number c, can modify the sum of the individual
dice. +-*/ are similar in that they take the sum of the rolls and add or
subtract c, or multiply or divide the sum by c. (x can also be used instead of
*.) Hence, 1d6+2 gives a number in the range 3..8, and 2d4*10 gives a number in
the range 20..80. (Using / truncates the result to an int after dividing.) Using
b in this slot is a little different: it's short for "best" and indicates "roll
a number of dice, but add together only the best few". For example, 5d6b3 rolls
five six- sided dice and adds together the three best rolls. This is sometimes
used, for example, in role-playing to give higher averages.