Dice refers to any die with more than six sides, because Role-playing nerds are too good for Monopoly dice. Their best use is as a weapon: hide it in the chip bowl and wait for someone to choke. Very versatile, and you'll have saved the world from another Lifetime Channel wedding show of fat brides wearing purple robes and grooms carrying swords.
Everyone knows that the awesomeness of your die is precisely equal to the awesomeness of your cock. Not only do they show that you are TRULY a hardcore gamer, but they roll higher than any mundane plastic die possibly could. Plus, the high-end models do far more damage when hurled directly into your friend's eye! As such, you MUST throw down at least $100 on solid gold dice. Since nerds don't have girlfriends to waste their money, this does not present a problem.
The most important numbers on a d20 die are the numbers 1 and 20. Rolling a 1 is like projecting your real life directly onto your character; i.e. they fail astronomically at everything. For example, going to open a door and instead decapitating yourself. Roleplaying nerds need to roll die for every action: tying shoes, taking a piss, or deciding which episode of Battlestar Galactica to fap to.