Stated up for original original D&D.
Gary has long been an science fiction and fantasy fan, starting from his days as a boy. He was active in fandom at the time, and did correspond with a number of the leading lights of the day. I believe Fritz Leiber played in a few games, and Jack Vance showed an interest. As a matter of fact, Jack played an active role in the design and development of the
Dying Earth RPG.
Jack and Gary get to talking about Gary's new game. The subject of magic items in D&D comes up, and Jack offers to allow the use of his ioun stones in D&D. They hash out the stats and Jack writes a few lines of text. Their efforts makes it into issue 4 of
The Strategic Review under Jack's byline. Thus is a D&D staple born.
My point? The big names in science fiction and fantasy are approachable. It's a tradition that was established long ago, and largely arose out of the fact most science fiction and fantasy writers were once fans themselves. And a large number are still fans. Say hi, strike up a conversation, but refrain from gushing and acting like a fanboy. Who knows, you might get Fred Pohl involved in your Heechee RPG project.