So a recent read of an old blog article about
calibrating your expectations, and how 6th level D&D characters are the equivalent of the pinnacle of human ability (Olympic athletes, etc), got me to thinking on things a bit.
First, I know of E6 and E8. I don't know a lot of the nitty-gritty, but I understand the basic concept. That's certainly a valid approach to dealing with the insanity that is high-level D&D. My idea is not that.
Having run a Gestalt game from 1st to 20th level, I have experienced the crazy that constitutes high-teens D&D. Trying to run such a game got so monotonous and pointless, that I suspended the campaign once they reached 20th level, rather than continue on into Epic as I had originally intended. I'm sure we'll go back and play epic with those characters someday, but I needed a break. We're playing an Eberron campaign in the mean time.
Anyway, back to the point of this whole post. The thought occurred to me, "what if the only casters were Bards, Adepts, and classes like that?" This would include Magewright from the ECS, Duskblades, PrC's that get their own casting progression up to 5th level spells (so no Ur-Priest, Blighter, Apostle of Peace, Nar Demonbinder, Artificer, etc.)
This idea takes two forms. The first is basically as I described above; only Bards, Adepts, Duskblades, Rangers, Paladins, Hexblades, Warlocks (maybe), and PrC's such as Assassin would exist. In this format, the Extra Spell feat would use the interpretation that any spell could be chosen and added to your list, so your Adept could learn Lesser Planar Ally, etc. Also, classes like Fiend-Blooded, Lyric Thaumaturge, and Unseen Seer could still be used to gain spell knowledge outside a class's normal list.
Monsters that gain full casting, such as dragons, would have their CR's adjusted upward (how much would be appropriate, I'm not sure).
The second form of this idea is to allow Cleric, Druid, Sorcerer, Wizard, Beguiler, etc, but alter their spell progression to be in line with Adepts (2nd level spells at 4th level, 3rd at 8th, 4th at 12th, and 5th at 16th). Basically, just take the normal spell progression, but shove the column for each spell level down until it starts at the above-listed levels.
In this form, monster casters would have their casting altered as well.
One effect these alterations would have, is greater reliance on seeking out assistance from powerful beings, be that Angels, Archons, Demons, Devils, Genies, etc. I think it would also calibrate the game into the power levels many DM's expect the levels to break into (rightly or wrongly, many DM's get frustrated when they are running a game at 12th level, but are only expecting magical effects on the power level of a 6th level party). It would also create a slightly-humourous juxtaposition in that Bards would be the "most powerful casting class," as they would be the only ones to get 6th level spells.
These changes would increase the deadliness and "fear factor" of wights and vampires, as Restoration spells aren't available until 12th level. It would encourage players to dabble in PrC's that routinely get completely ignored, because they grant their own casting, rather than advancing that of a base class.
One last option that would end up with a similar result, is requiring all full casters (including dread necromancers, etc) to multiclass every other level. So at most they could have 5 Wizard levels at 10th level, and 10 wizard levels (or their equivalent) at 20th level. This seems a slightly more clumsy way of doing it, but it would end up with a similar result.
This type of campaign would pretty much have to be a series of home-designed adventures. Published modules would likely have to be heavily altered in some way to account for the changes, and limitations of the party.
Is this idea completely crazy? Does a campaign like this sound fun? What other effects would this have on the game?