So my good friend (and Narrator) SuentisPo and I were bouncing around ideas based on the way magic works in Dragon Age, and they went and mutated on us into the seed of an interesting new setting. Comments and suggestions are welcome!
Basically, there exists a continuum of ability stretching from natural mages, through normals, to "nulls", people who are actively unmagical. Mages are magical sources, nulls are magical sinks.
"Mage" is the base feat in a chain. It must be taken at 1st level. (Elves get it as part of their background.) Mages can take the Adept role (using Cha as their key ability), and if they take another role can swap out its core ability for the Talent if desired.
Mages do not suffer fatigue from powers. Rather, they "surge". We're still working out the details, but basically when a mage fails their "fatigue" save, they have a possibility of "blowing their top" - losing control of their magic. If they don't, they gain a surge point - which makes subsequent saves harder, and the eventual surge nastier. Surge points can only be lost by surging, or very slowly between adventures. (Something like 1 per week if you insist on a precise number.)
Due to the sheer magical power flowing out of them, there are some magical things mages *can't* do. They can't imbue items, even single-use ones like potions, and they can't be Sensitives (see below). Basically, the mage's raw power messes up the magical resonances of the materials being used. They can't even *use* most magic items.
(As we'll see below, Imbue Item has become a General feat with prerequisites of "Trained in Knowledge: Supernatural" and "Not having Mage or Null". We may use the Artificer idea, in which you take feats to gain access to 3 powers for purposes of imbuing. But mostly items will be made by Arcanists, below.)
Mages get some other benefits that we haven't finalized yet. Some may end up part of the Mage feat, others may become further feats in the chain. Some possibilities:
* They are the only ones who can take Innate Power, and may get an instance of it for free.
* There may be a feat they can take somewhat like Lucky that only applies to saves vs. powers. (It doesn't stack with Lucky, naturally, which may even disappear.)
* Mages have sole access to the "mana" powers - Mana Blast and the like. In fact, they may be the first powers any mage learns - we may have to come up with a way to incentivize that.
* Severance doesn't work on mages, or at any rate it takes a lot more oomph.
"Null" is also the first feat in a chain. (Dwarves get to choose between taking Null or Imbue Item as a background feat.) Its base level gives you +2 to all saves vs. powers. Subsequent feats can make you more and more immune to magic or give you the ability to dispel it and otherwise interfere with it. High on the chain will be feats that let you absorb powers to heal yourself or the like. Nulls have trouble using magic items.
"Sensitive" is a General feat with the prerequisite "Neither Mage nor Null". It represents being more magically attuned than the typical norm. We're not sure of the details yet, but it will give some elements of Second Sight, and the ability to "sniff" the recent use of magic. (Half-elves get to choose between taking Mage or Sensitive as a background feat.)
Now. Norms, those with neither Mage nor Null, can take levels in the Arcanist role from the Companion. (We're pondering switching out the core ability for Ultimate Knowledge, though.) These represent norms who have learned to use magic via hard work and study - they use Int as their key ability. (Arcanists get Slow, Unlimited powers and 8 skill ranks per level. Their base core ability is Ultimate Will Save.)
Arcanists, unlike mages, can imbue items. They can also be Sensitives (and not uncommonly are). They take fatigue from powers as per usual.
There's another neat trick that Arcanists can do - or rather, receive. Being neither sources nor sinks for magic, Arcanists manipulate the flow around them. This means that mages and nulls can help them by adjusting the flow - they can use Concentration to Aid an arcanist in casting a spell. The Arcanist takes the total bonus and gets to choose whether to use it to boost his ranks of power, or his fatigue save. He can mix and match, too.
Arcanists have access to a supernatural feat that lets them redirect spells they successfully Ward.
We've also discussed the possibility of *regions* that are "high magery" or "null". High magery regions let arcanists use power at Fast rank instead of slow - but also cause them to surge. Mages surge like *crazy*, but probably get some really nice benefits in exchange - like being able to spend the equivalent of Conviction on powers by accepting surge or the like. Null powers wouldn't work at all.
Null regions make nulls virtually immune to magic, and slash the ranks of powers in half.