RDice 
This gem was created with studies purpose. It simple create a dice and let you roll one or more dices with different sides.
Installation
Add to your Gemfile and run the bundle command to install it.
gem "rdice"Tested with Ruby 1.9.3
Usage
The most basic use you can create a new instance of Dice and perform some rolls. The returned value is a integer containing the sum of all dices rolled
require 'dice'
dice = Dice.new
dice.roll # rolls one dice with six sides by default
dice.roll_two # rolls two d6
dice.roll_d20 # rolls one d20
dice.roll_three_d8 # rolls three d8
dice.roll_10_d3 # rolls ten d3
# You can call the method roll directly if you preffer, just pass the number of sides and dices
# dice.roll(20,4)This gem comes with shortcuts of one to twenty so you can call .roll_four_d12. If you want a dice with more than twenty sides you can explicit declare the number of sides with .roll_32_d3
If you call roll with only the number of times you want to roll it will roll the default dice with the required number of times.
Changing the defaults
When you call .roll method this roll a dice with the defaults sides and dices number (6 and 1). If you want to change the defaults you can in the class creation
dice = Dice.new(20,2)
dice.roll # rolls two d20 by default
dice.roll_two # rolls two d20
dice.roll_four # rolls four d20
dice.roll_d20 # rolls two d20
dice.roll_three_d8 # rolls three d8
dice.roll_10_d3 # rolls ten d3There are three configs that you can change
Dice::Config.sides= 12 # set the default dice sides to 12
Dice::Config.dices= 3 # set default dices rolled to 3
Dice::Config.array= true # change the result to a array without sum the dices
# All these preferences can be setted on creation with
dice = Dice.new(6,3,true) # by default roll three dices with six sides and return a array as result
dice.roll # => [1, 5, 4]License
RDice is released under the MIT license: http://www.opensource.org/licenses/MIT