Some of the entries that Gary Gygax included when he wrote the AD&D Dungeon Master’s Guide’s Appendix N: Recommended and Inspirational Reading are harder to make sense of than others. The trickiest are those where an author is listed, rather than specific works, and said author’s works are science fiction rather than fantasy.
That said, it’s very satisfying when you can connect the dots. Stanley Weinbaum is one of the writers whose connection to D&D I’ve always found the most mysterious, so recently I used Paperback Swap to pick up a Ballantine collection of The Best of Stanley G. Weinbaum. Isaac Asimov wrote the introduction, and one passage in particular really struck me:
Now what was most characteristic of Weinbaum’s stories? What was it that most fascinated the readers? The answer is easy – his extra-terrestrial creatures… The pre-Weinbaum extra-terrestrial, whether humanoid or monstrous, served only to impinge on the hero, to serve as a menace or a means of rescue, to be evil or good in strictly human terms — never to be something in itself, independent of mankind. Weinbaum was the first, as far as I know, to create extra-terrestrials that had their own reasons for existing.
What caught my eye about this was its resemblance to what James Malizewski described as Gygaxian “Naturalism” in a famous Grognardia post:
a tendency, present in the OD&D rules and reaching its fullest flower in AD&D, to go beyond describing monsters purely as opponents/obstacles for the player characters by giving game mechanics that serve little purpose other than to ground those monsters in the campaign world… The intention behind Gygaxian Naturalism is to paint a picture of a “real” world, which is to say, a world that exists for reasons other than purely gaming ones. The implication is that monsters have lives of their own and thus go about their business doing various things until they encounter the player characters.
I think there’s a compelling argument that the thing that Gygax found inspirational in Weinbaum’s fiction was exactly this lesson about monsters having lives of their own, which he later expressed in the idiom of D&D rather than its near cousin, science fiction. As another example of overlap, here’s Asimov again from the introduction:
In Weinbaum’s stories, the plots, though tightly and well-constructed, exist in the reader’s mind largely for the opportunity they present for a voyage of discovery of strange worlds and of ever-fascinating life forms.
There isn’t, so far as I know, a single phrase or post that captures this comparable idea that D&D is a game of exploration, but I think it’s an aspect of the same thing. Seems to me that for both Gygax and Weinbaum, what Grognardia identified as naturalism was not a goal in itself but rather a potent tool used to help enable a voyage of discovery.