I think it is helpful to distinguish tropes (which in D&D become game elements) and the actual themes, stories, "orientation" of game play.Honestly, the only Conan I've actually read is Red Nails. I was just thinking of the bit where Conan and Valeria are navigating the ruined labyrinth of jade; that scene has the atmosphere of a D&D dungeon. If that seems like a superficial resemblance to you, well, that's how the Tolkien comparisons sound to me.![]()
D&D draws very heavily on JRRT tropes - they've been listed upthread. I think we disagree on the extent of that dependency - for instance, I think the comparative shortness of D&D elves is less significant than the overwhelming points of overlap (eg in addition to what's already been mentioned, there is the use of "high elves" as a term, the idea of different people among the elves where sylvan elves are the least bright and most rustic, etc).
I don't think default D&D plays much like either REH Conan or LotR. It plays more like a small unit wargame - the PCs scout, advance with caution systematically loot the dungeon, etc.
To emulate either REH or JRRT there need to be mechanical changes that make courage, risk-taking and chance possible. (And then depending how that is thematised, it might be more like REH's modernism or JRRT's somewhat reactionary romanticism.)