Jeff Dee was an illustrator for TSR Hobbies in the early days of Dungeons & Dragons. His work has since appeared in many other games. He co-wrote and illustrated Villains & Vigilantes, a superhero role-playing game from Fantasy Games Unlimited. In 1990 he moved to Austin, Texas where he became an artist for Origin, the publishers of the Ultima line of computer role-playing games. In recent years he's been doing game design in the computer game industry, and has published several of his own paper RPG projects through two different companies  .
He was one of the founding members of the Atheist Community of Austin, a non-profit group that was formed in the wake of the departure of American Atheists to New Jersey. He began their bi-weekly internet audio program, The Non-Prophets.
Jeff has posted several essays on his web site , many of which make his atheism perfectly clear. For example, here's a quote from his essay, "Enough is Enough. Theism is Evil", written in response to the outpouring of religion after 9/11:
The self-proclaimed spokemen for this "divine lawgiver" are now coming out of the woodwork, taking advantage of everyone's shock and dismay in order to dig their claws even deeper into our culture. Don't fall for it! Belief in gods is the cause of atrocities like this, not the solution.