Being rather pedantic, Aretae sticks with the actual definitions of the words atheist and agnostic:
Theism and Atheism are positions about belief in a god. Gnosticism and Agnosticism are positions about whether you can know things — and usually talking about the ability to know about God.
I, like 95% of all the other atheists I know are Agnostic Atheists. We do not believe in a god. And we do not believe that such a thing is knowable. And mostly, we think that the question is silly, along with the question of whether you are an A-Thor-ist, an A-Faerie-ist, or an A-6-dimensional invisible blue banana-ist. Yeah, whatever.
(If you’re trying to promote skepticism, I think the 1st edition AD&D Deities & Demigods book may be the best inoculation ever.)
The evangelical Christians were so afraid that D&D would convert nice little Christian children into devil-worshipers, when it really did something far worse; it turned them into non-worshipers.
Actually, it didn’t do that either. If you’re not genetically predisposed, the inoculation appears totally ineffective.