Spelljammer seems not to have had the same impact. I don't remember much presence of it at all in the 3E books I've read, and in 4e it seems to turn up mostly in the form of Spelljamming ships as a 30th level item, and as plane travel devices they're actually kind of cool.I don't understand why the Blood Wars are so reviled, and yet the Crystal Spheres and Neogi seem to pass without comment.
I'm not carrying a torch for the 4e treatment of FR. (Nor the 3E treatment. I don't care about FR.)I didn't find that Planescape Lore/Cosmology did any of that (not more than 2e did natively, anyway). Certainly its influence outside its own campaign setting was less than 4e's cosmology. Which makes it odd for me to hear 4e fans grumble about Planescape in that context.
In terms of the "occult/gnostic" features of Planescape, though, here's an example of what I mean (from the other thread):
For clarity, my concern is not with secrets. It's with secrets that invalidate the cosmological assumptions within which the players have framed the choices for their PCs and their play more generally.For just a MM entry, I'm actually in favor of being silent on the subject. For a 'loth specific book, go all in, but the MM should present the core of their being as greedy, self-centered, devious evil that sells their services to the highest bidder, with some sages suspecting something deeper, darker, and more manipulative beyond that for the race as a whole. You can hint at earlier lore without strictly saying it's true, and giving both PS fans a nod and not locking everyone else into that body of lore if they choose to go a different route.
That's part-and-parcel of Call of Cthulhu, but CoC is expressly about hanging on for the GM's ride. I personally don't like it being generalised into D&D.