RPG’s and Twenty-Sided Dice

I have been reading through several RPG’s and realized I will need a few sets of twenty-sided dice. The d20 (twenty-sided dice) mechanic is a role-playing game system that was first published in 2000 by Wizards of the Coast. I came across the GM DICE site that offers dice of all sorts. GMDice also offers miniatures for RPG play and several games.