In various editions of Dungeons and Dragons, elves have the ability to "trance" rather than sleeping normally. Does this elven trance have a source from fiction? I know that almost everything in D&D that I've run into so far has a source or inspiration from older works, but I'm not aware of any works that mention elves replacing sleep with a trance.
Does the concept of elves "trancing" rather than sleeping come from an older work, or was that idea made up from whole cloth by D&D designers?
The inspiration for it, like for many other things, comes from Tolkien and The Lord of the Rings, specifically the part where Aragorn, Legolas and Gimli chase down the orcs that have taken Merry and Pippin. Here's the direct quote:
Only Legolas still stepped as lightly as ever, his feet hardly seeming to press the grass. leaving no footprints as he passed; but in the waybread of the Elves he found all the sustenance that he needed, and he could sleep, if sleep it could be called by Men, resting his mind in the strange paths of elvish dreams, even as he walked open-eyed in the light of this world.
— J.R.R. Tolkien, The Lord of the Rings, Book III, ch.2, "The Riders of Rohan"
I would guess that this, as well as some other quotes from the same chapter (like "As before Legolas was first afoot, if indeed he had ever slept", and other supporting quotes) are the inspiration for "elves don't need sleep" trope that D&D embraced
