I debated whether to weigh in on the discussion about Tolkien's influence on D&D, seen on Grognardia and other places. I lost.
The Tolkien elements are pretty minimal. Elves and dwarves exist in pre-Tolkien fiction; so do little people (halflings or hobbits.) Orcs, even in Tolkien, are really just bigger goblins. "Barrow-wight" is technically an English translation of Daoine Sidhe, although Tolkien turns them into ghosts. Ents, Balrogs, and mithril are definitely Tolkien, and were-bears seem to be, as are elven cloaks and boots. Rangers, too. And dragons can talk and seem fully intelligent, as opposed to the way they're usually presented in western myth and literature pre-Tolkien, although Dickson's "St. Dragon and the George" (1957) is a significant exception.
Consider also what D&D didn't take from Tolkien. Magic in Tolkien is pretty stunted. Gandalf knows how to make light and fire, but apparently only because he wears the elven ring of fire. He's literally a wizard: a wise one, someone who knows a lot of old lore. The only other magicians are ring-wielders (Elrond, Galadriel) or ring-makers (Sauron.) It's been decades since I've read LotR, but I don't recall Sauruman doing any of the magic tricks in the book that you see in the movie. Giant spiders can be intelligent in Tolkien, but are more like animals in D&D.
The main thing Tolkien did to D&D was humanize the elves, dwarves and little people. Elves in Tolkien are non-ghost versions of the Daoine Sidhe. Elves or fae exist in numerous fairy tales, Arthurian romance, and in pulp fiction, like A. Merritt's "The Woman of the Wood". But these are weird, otherworldly beings; Tolkien downsized elves considerably. Dwarves, of course, used to be called dwarfs, drow, trow, or trolls, and are everywhere in fairy tales; Tolkien changed the spelling of the plural and made them bearded miner/warriors, which stuck in D&D. Little people used to be brownies, leprechauns, and the like, but again Tolkien named them, took the magic out, and gave them some traits and behaviors that stuck in D&D.
Without Tolkien, elves, dwarves and little people would have definitely been included in D&D, but would have been closer to their sources, and probably not as character races. That would have definitely changed the hobby; "race as class" would be the norm. So Tolkien's influence is simultaneous narrow and deep.
Edit: Duh, "St. Dragon and the George" wasn't written in 1057.