Sorry if I'm rehashing an old topic (and chances are I am), but the last thread about inspiration sources I can remember seeing in this forum was inspiration from other RPGs.
But the other day I was reading a Lovecraft novel and trying to think of the most obvious fantasy/sci-fi novels I've drawn inspiration from for my planar campaigns. I think these were the main ones I could think of:
. Chronicles of Amber: IMO the best and most comprehensive fantasy series on planar travel. Or the best fantasy series ever, period. I think Zelazny deals with the whole law-chaos axis in a much more interesting way than the Elric series.
. Lovecraft: Especially for Far Realm related stuff, but also on general matters pertaining to the metaphysics of the cosmos.
. China Mieville: His novels are laden with references to different dimensions and weird extradimensional creatures and artifacts. The Scar is my favorite.
. The Silmarillion: I have yet to see a better depiction of elves and their "home plane" than the one developed by Tolkien. It's funny that the elf archetype that stuck in the fantasy genre were his elves from the Third Age (from the Lord of the Rings), when in fact the First Age elves (Silmarillion) are sooo much more interesting.
. Song of Ice and Fire: No planar travel here, but also an amazing series and a wonderful source of inspiration for characters.
Does anyone else draw inspiration from fantasy or sci fi novels for their campaigns?
Jonathan Strange & Mr Norrell. Okay, maybe not necessarily a Planescape-specific type of inspiration, but it certainly got me in the mood for Sigil.
Also, Flatland? Always.