Since we're already engaged in threadcromancy,
I don't like E6. I don't want to limit power, just spells.
Originally Posted by ImperatorK
This can be done without restricting classes. Various articles have been written, published, discussed, revised, and republished over the years on how to deal with just this idea. It boils down to going through the entire spell list level by level and deciding which spells are widely known and which are completely unknown.
The common-knowledge spells are the ones wizards can learn automatically as they level, and that divine casters can simply pray for. Unknown spells are just that - unknown, and utterly unavailable. Such spells can be used as treasure or even moved into the concept of "ritual magic", that is, they're much too powerful to simply be memorized and cast in a handful of seconds. Many 7th and 8th level spells, and nearly all of the 9th level spell list, could be shifted to "ritual magic" that requires special (i.e., expensive) material components and minutes to hours to cast.
There is a vast library of fantasy literature that supports this idea, though most of it would fall into the concept of "low magic setting". Eberron took this in a different direction with the concept of magewrights and commoditized magic, where low-level magic is quite commonplace and used the way we use technology: lights, transportation, sanitation, communication, etc. The setting specifically states that high-level magic is rare, but does stop short of restricting PC advancement or class abilities.
Ultimately, however, limiting spells does
limit power. That's the way 3.5 works. Google "3.5 Tiers" for as much discussion on the matter as you can stand; we won't be engaging that conversation here.
Is it really low-magic when the whole setting is still using magic normally?
I believe this was noted earlier, but if you're restricting what the players can do, the "whole setting" isn't "using magic normally". Any adjustment to the PCs must equally apply across the entire setting, or you're simply screwing your players. Reference the commentary about gestalt classes in Unearthed Arcana
if you need any additional support for this argument.