D&D was created in the 60’s (I believe) by Gary Gygax (who recently died ) and some other guy who I can’t remember the name of.
It was originally based of the LotR idea and every single Fantasy game, every single MMORPG and RPG game are all based off D&D.
As you may of have guessed, it’s an RPG game but instead of it being on computer, it’s played using the imagination, writing stuff down and boards/cards/miniatures that you can collect.
It’s also the ultimate level of Nerd-hood.
The game is now run by Wizards of the Coast and you can find out more about it here:
http://www.wizards.com/