Savage Wombat - two things. Number one, the Monstrous Compendium came out about half way through 2e and drew from a number of sources. Secondly, 2e and specifically TSR, tried to create the idea that every setting was all one. They tried to unify the settings through Planescape, and, to a lesser degree, Spelljammer.
Which meant that Planescape lore began in 2e, to infiltrate pretty much the entire line. 3e was, IMO, a breath of fresh air in that it rejected most of Planescape lore, or left it on the cutting room floor, or put it back into setting specific books, where, again IMO, it belongs.
4e took 3e a step further and began reexamining a lot of the existent lore with the idea that maybe some of that stuff wasn't quite as good as it could be. Which led to all sorts of issues with people judging the new material, not based on its own merits, but on how far it deviated from what came before. Eladrin were bad, not because blink elves are bad, but because Eladrin had to be Angel Elves as defined in Planescape. Succubi couldn't possibly be devils since the game had always had them as demons. Whether or not they actually fit there wasn't the issue. What came before must be preserved.
What you're claiming is that the "core" yugoloth has no identity, and creating an identity for fifth ed isn't changing canon. What we're claiming is that the "core" yugoloth was revised by the introduction of 2.0, and elaborated on in Planescape materials.
See, that's the issue though. The Yugoloth, or Daemon, was changed by Planescape to fit with Planescape canon. Yugoloth as the evil behind the evil is a major revision of what came before. It makes perfect sense in Planescape. And I have no problems with it being in Planescape. I'm just not sure why the Planescape, setting specific version, is considered the core version.
The only people who think that the elaborated Yugoloth is the core version is Planescape fans. The rest of us don't.
KM said:
Turns out, PS planar lore is some of the best lore written for the Great Wheel...in fact, some of the best lore ever written for the D&D game, IMO. And even if you don't agree with that obvious fanboi opinion, it is widely agreed, and reflected in your own polling data, that PS lore is quite good lore.
I'd say that it's pretty easy to be best in a field of one. No one was ever allowed to change Planescape lore, so we never got to see anything else. At least, not until 4e. Like Shemeska said earlier, if you wanted to get printed in Dragon or Dungeon, you had to do your PS homework and make sure it was all PS compatible. I'm thinking that has a LOT to do with the editorial staff at Dungeon and Dragon at the time.
Not until 4e did we even get the inkling of another cosmology for D&D. For twenty years, or there abouts, the Planescape bunch had the field sewn up tight and no one could get a word in edgewise. Any change was immediately jumped on as bad if it did not follow Planescape canon. Should Slaad be outsiders or Far Realms creatures? I don't know. I'd like to be able to discuss the merits of both ideas though without having people tell me that I'm wrong if I think Far Realms might be a good idea. Could Modrons be changed to make them a bit easier to use at the table and not so niche? I think so, but, any proposed change gets shouted down because it's not Planescape. Could Yugoloth worship gods? No. Absolutely not, because it counters Planescape lore. Could Demons and devils work together? Again, absolutely not because it counters Planescape lore. On and on and on.
Go back through every recent thread on the Wandering Monsters related to anything planar. You'll see it over and over again. Any proposed change is automatically rejected if it does not follow, to the letter, setting specific material.
I have no interest in "maximal" lore, if maximal means Planescape Uber Alles.