Thanks a lot for the updates guys!
So stoked to hear this. As I am well versed in Athasian lore but no practical experience with playing or DM-ing in anything but 2E/5E and Pathfinder I fear I would only be able to help out with proofreading/editorial stuff if that is even needed at all.
We could also use help in spinning out lore, writing evocative descriptions and that sort of thing - so if you’re a decent writer, but not well versed in the 3.5e’s mechanics, we could harness that talent!
Seriously?!
Bah!
Humbug!!
A pox upon all magic and magic users alike!!!
More psionics please.
Calm down bro, ~1/3 of the NPCs are psions or psi-warriors. 
But, there SHOULD be a lot of magic in the DL, everyone died during the Cleansing Wars - when magic was the hot new weapon of war.
Lol.
If it only exists in history, I suppose I can suppress myself to merely grumbling.
Well, they’re the reanimated undead FROM the Cleansing Wars. Lots of psions, lots of Defilers. Trolls and Kobolds too.
There’s also the whole issue of necromancy. Psionics may take center stage, but undead play a huge role in Athas. I could see necromancy getting a great deal of advancement in the Dead Lands. The curious detail imo is if necromancy is defiling/preserving or if it draws power from the Grey rather than life energy? A possible way to separate necromancy while keeping with the themes of magic harming the environment when used irresponsibly is that necromancy weakens the barrier between our world and the Grey, causing regions to become haunted. Though that may be a topic for another thread.
I posted a heresy over in the Heresies of Athas thread about undead as healers of Athas, if you are interested.
@Star-Sage the question you ask about necromantic magic being defiling/preserving is somewhat answered in the book TSR 2445 Defilers and Preservers - The Wizards of Athas.
There it says in the necromancer kit description (page 64-65) they get their energy from the Gray, either when casting the spell or when memorizing. But it also says, since it is a kit, that they can be either defilers or preservers and that the defiling option is the easier one to follow since defilers get easier access to spells that come logically to the necromancer (explained on page 22-23 under the Threefold Path heading; basically necromancy spells fall under the so-called Path Sinister which causes Defiler wizards to receive a +15% bonus to learn a spell and Preservers to receive a -15% penalty to learn a spell).
Mind you, those are 2E edition rules. I’m not up to speed if there are rules on this that reflect the detail from this accessory under the 3.5E rules or 4/5E.
According to Defilers and Preservers, necromancer magic is fuelled by the Gray and doesn’t affect the terrain when a spell is cast, so it isn’t preserving or defiling magic.
And that gives me an idea for what I think is an interesting plot for the DL Lords. It all starts with the next points:
Then, to make easier to open a path through the Gray to the Outer Planes, what is needed is to reduce the power of the Gray. That can be done by stopping the entrance of new energy and by consuming the existing one. Both things can be accomplished by the Dead Lands inhabitants by one “simple” action: opening again the gate to the Plane of Obsidian.
The resulting obsidian wave will kill all living beings touched and will transform them into undeads, powering the Gray with new souls energy temporarily, but blocking the possibility to get new souls in the future (if they can’t reproduce, they can’t power it with their souls). Morre undeads, tens of thousands of them, plus the use of necromancy would mean an increase in the use of Gray energy, thinnering it. At the end it would be “easy” for a powerful necromancer to cross the Gray to the outer planes… with an enormous undead army.
As a sidepoint, it would also make sense for those necromancers to start teaching their art to existing living wizards, to speed up the use of Gray energy without their knowledge.
Good stuff everyone!
Yes, I can confirm in the Dead Lands books that necromancy is indeed powered by the Grey (we call it “greycasting” in 3.5e). It’s also mentioned in passing in Terrors of the Dead Lands as well.
Given your guys’ great ideas, I cannot wait to see what happens when you all playtest this. 
I absolutely love this plot twist!
The idea of using enough necromancy to “drain the Grey” is a positively insane idea. Even more insane would be channelling that power into regrowth.
What if a powerful avangion and a big name Necromant got together and decided to “end this madness” and give the world another chance? In the name of preserving their own lives and the lives of most of the Tablelands, the PC’s would find themselves opposing the regrowth of the world!
(In case you couldn’t tell, I’m rather a fan of high-stakes confrontations for epic adventures. Must be my background in superhero adventure writing…)
I run all my games like a comic book setting. It may start off small and local, but stick it out and before you know it you’ll be saving the village, then town, then kingdom, then continent, the whole world, and eventually your plane of existence. I don’t have to stop there either!
I’m glad you liked the idea 
The thing is, I don’t like the alternative magic energies sources (necromancy and cerulean). I think they take out a great part of the flavor of Dark Sun and minimize the defiling problem.
For my games, as they are canon, what I would make is to restrict the use of necromancy to undead beings. This would be explained by the connection they have with that plane, which living being would not be able to have.
With that change, the avangion plot would not work (again, for me). But we already have a nice undead SK, able to move on this kind of plot: Dregoth. And as I never played the Dregoth Ascendig adventure, I think I’ll modify it to use the “thinnering the Gray” idea instead of the “switch the spiritual conduits”, which I don’t really like.
One compromise I would propose— necromancy turns everyone who uses it evil, like the dark side of the force. It also tends to have effects on the environment. You’re literally powering your magic with the souls of the dead. Maybe it turns you into an undead after long enough…
This could still make the avangion plot work. They’re fixing the world by destroying it and resetting everything. This would be a wonderfully weird situation where then main enemy is “good”, and the forces of evil are battling alongside you to protect the status quo.
Love this. I really like the idea of defiling the Gray.
The Grey Jedi would like to have a pleasant chat with you about the force…
I have an autographed picture of Mark Hamill from Return of the Jedi. I think that means I can do no wrong in the eyes of the Force. 
TFW no autographed picture of Mark Hamill from The Last Jedi.
Yeah, waiting for Yoda’s ghost to come, cast Call Lightning on your autographed photo, and tell you: “Meaningless your notions-preconceived are.”