Well, I suppose that pioneers often treat their subject with more free reign than those following them, because the boundaries aren't as well defined.
Yep. But they're now oldschool, hindsight shows that they were pioneers on top of that, and they're somewhat more obscure in this day than Tolkien, Eddings or Jordan, sorting out the more recent or casual fantasy fans from those who've been paying attention for some time. That you can see the influence of Moorcock, Vance etc. in D&D fairly strongly further reinforces their "respect factor" among players of the game, I'd say - on top of any other respect they are worthy of, of course.
Lovecraft, especially, seems to have come to represent a panoply of things to the RPG community in particular (and to the horror community as well, perhaps) that extend far beyond the stories he wrote, as if others dug the theme, picked up the ball and ran with it to an extent that is perhaps only rivalled or exceeded by Tolkien. Howard, too, set up such strong themes rolling in Hyboria that a bunch of other authors were able to carry on writing Conan in his stead. I respect these things. However, despite all this I sometimes think their names come up slightly too often, as if they're there to lend credibility to something or someone - but as you say, and I suspected, this is probably just me being a bit cynical.
Erol Otis as opposed to Todd Lockwood, for instance.
I've read a bit of each, but not for a long time, so will express what I think they stand for as of now...
The styles of Moorcock and Tolkien don't really mix very well, if you believe Moorcock - he complains that Tolkien (like C.S. Lewis) is forever going "there there, there's danger but in the end the hobbits will be alright", which is almost the antithesis of the flavour his work has. I've heard him called dark fantasy before, but not in the horror sense - Elric sort of means well, but everything goes to pot anyway.
I find that Howard is good with action scenes and in portraying heroics in general. In these respects I think he has something in common with Salvatore (who does great fight scenes) and Gemmell (who portrays strongly defined heroes). His short stories often seem, to me, like D&D done "monster lite", with savages and snake cults in place of goblins and yuan-ti. A source of amusement for me is in seeing what weapon Conan will pick up and use for a story or two next.
I read some of The King of Elfland's Daughter, and the main thing I remember about it is the massive and evocative vocabulary Lord Dunsany must have had, using words that haven't seen much currency for a century or so. He's the man when it comes to describing hedgerows in spring. I don't think I got to the end of that book, though - maybe things were moving too slowly?
Leiber seems to be a strong influence too, because when Gygax does write, his characters and their hijinks seem to come out rather Leiberesque - despite his protestations to the contrary in Dragon. Again with the Tolkien influences in the game (e.g. Balor = Balrog) despite his protests (in Dragon, again) that he's not as much of an influence as everyone thinks - which might very well be true, because Tolkien generally gets big-noted a lot for all things fantasy.
Despite all this, I think the flavour of D&D derived from fiction is mashed together into the D&D "chicken" flavour pointed out earlier in this thread. To really look to the heart of oldschool D&D, I think that you have to consider Arneson's dungeon of Blackmoor Castle, the Chainmail heroes wandering through it, the monster mash that filled it, and the loot they carted out. I fail to see that theme reflected very strongly in fiction as a central theme, so you might even call it the heart of D&D - and although it is a theme that can be departed from, there are many stylistic variations on it. Diablo programmers coined it; to paraphrase them, their goal was to "Let the player kill something, then reward them for it." Perhaps that's the distilled essence of oldschool D&D, and a theme commented on by Greg Costikyan's Violence political-comment-as-RPG RPG - put it into a contemporary rather than fantasy context, and the theme becomes abomination rather than escapism!
You cite Planescape as new school, which is something I'll pay - it seems a long way from the dungeon, but a logical extension of it nonetheless. It seems fitting that one of the setting's creators - Monte Cook - has set up his Ptolus campaign with a very interesting idea - as a world based around the result of what D&D and it's rules imply. This seems to me to be a very postmodern idea for D&D, given that the usual formula seems to be to take a generic swords & sorcery fantasy default, clog it with D&D monsters and mores (such as "thieve's guilds" and "dungeons"), and fall back on vague modern anachronisms of medieval europe when in doubt. To come from the approach of interpreting what the rules literally imply with regards to the molding of a setting is to come full circle - an acknowledgement of the D&D flavour and the rules that support it being present, and carrying with them an atmosphere and culture of their own.
Good luck with oldschool flavour. Personally, I find it in back issues of Dungeon, but can understand using older fantasy fiction as a basis for overall flavour - although unless you're careful, it will probably have to compete with the default D&D "chicken" flavour.
