One aspect that I dearly miss from many D&D settings (and Golarion) is the absence of cosmological origins (or limitations) for the many “Power Sources” of the game (allow me to borrow a term from D&D 4th).
We have some wonderful exceptions, like Birthright, Dark Sun, Dragonlance and Scarred Lands. In Birthright, true arcane magic is the domain of those with either divine or elven blood – and there’re damn few! In Dragonlance, being a wizard requires a harrowing test that always costs something of the caster. In Scarred Lands, magic generates heat (a really bizarre effect to justify a S&S look to casters) and sorcerers derive their power from the splintered fragments of the titan Mesos. Finally, at Dark Sun magic itself is a corrupt force that feeds on the world’s life force. These implications lend an amazing flavor to all these classical settings. It strengths their themes and makes them unique. Greg Stolze’s REIGN has probably one of the all-time best chapters on Magic worldbuilding. The author reminds us that one of the most boring things in RPGs (or literature) is “vanilla” magic – supernatural powers that can be used practically as technology to do anything and come from “nowhere”. Who’s the killer? Cast a spell. How to reach point X? Cast a spell. Etc. That’s basically the reason why I like to come up with either complicated origins or dangerous bargain costs for spellcasters (like the fact that in my proposed Science Fantasy-take on Golarion all magic comes from the Great Old Ones).
I came up with the following ideas due (mostly) to the Malazan Book of the Fallen (a bag full of clichés and angst, but also a masterpiece of worldbuilding). In the same vein of my first article on the subject, these cosmological assumptions change many things about the way that Pathfinder’s classes work and interact with the setting. If too weird to be useful, I hope it can provide ideas or, at least, a good alternate Material Plane for your player character to visit.
It came from the Outer Plaaaaaane!
I’ll be using three Power Sources here: Arcane, Divine and Mystic. The oldest form of magic is Arcane. Wizards summon their powers from the other realms of existence by align themselves with them (almost like Erikson’s Warrens). Wizardry is basically the invocation and channeling of extraplanar magic. Player characters races (humans, demihumans and such) are capable of aligning themselves with just one Outer Plane. Each Arcane School is then aligned with a particular plane from the Outer Sphere.
Wizardry doesn’t come for free; by channeling a Plane’s power the caster is likewise touched by that Realm’s forces. Influence goes both ways. It’s the old Law of Contagion. So, if an Enchanter pulls too much power from Hell, he’ll get more aligned with that Plane (maybe attracting devils, getting tiefling traits or just becoming extremely Lawful).
As the original Pathfinder cosmology was not created around this idea, the following connections will surely sound odd and are just a suggestion to illustrate this article’s idea. Here is my first sketch:
Abjuration -> Heaven (Antagonist Planes: Hell and Abaddon)
Divination -> Nirvana (Antagonist Planes: Hell and the Maelstrom)
Enchantment -> Hell (Antagonist Planes: Heaven and Nirvana)
Evocation -> The Maelstrom (Antagonist Planes: Nirvana and Elysium)
Illusion -> Elysium (Antagonist Planes: Nirvana and First World)
Necromancy -> The Boneyard (Antagonist Planes: Hell and First World)
Shadow -> Abaddon (Antagonist Planes: Nirvana and First World)
Transmutation -> First World (Antagonist Planes: Boneyard and Shadow)
I made some alterations, as you can see. I removed the Conjuration and Universalist arcane schools. I upgraded Shadow and made it into a full school, to accommodate Abaddon’s soul-drinking daemons. I also made the First World a true Outer Plane to hold the Transmutation school.
Creating the above connections establish some strange but potentially interesting consequences: Enchanters are now Hell-wizards. They aren’t evil, but their charming and dominating spells easily led them to the Dark Paths of Hell. Evocators tend to be chaotic and dangerous (which actually make sense). Illusionists are arrogant tricksters (like the Azata) and Diviners are dedicated to the "Ultimate Truth" (almost like Angels).
The normal rules for school specialization apply, although I prefer simply to forbid Wizards from casting spells of their Antagonist Planes (as you can see I already fixed these planes above). The fact that the Conjuration school is now “open” to all casters lessens the impact for reducing a caster spell list.
I’m also establishing that all Wizards are limited in conjuring outsiders only from their chosen Plane (which can become tricky).
How about the Planar influence over a Wizard? I really don’t know how to do it (besides flavor). I was thinking about a Planar Threshold. Each time a Wizard cast a spell he accumulates a number of Taint Points equal to the Spell Level. If this value is higher than the Wizard’s Planar Threshold he becomes to suffer outsider influence – alignment chances, physical mutations, madness… Maybe Taint Points reduce a fixed rate per day, or after some ritual. I’m not sure yet.
Well, so now we know that Wizards were the first type of spellcasters. That be aligning with one of the Outer Planes they accumulate power to cast spells. Each Outer Plane desires control over the Material Plane and will influence their respective arcane casters. Maybe close proximity to Antagonist Planar magic causes a Wizard to suffer some penalty or strange side effects. Wizards will then distrust casters from other Planes.
You’ll note that I didn’t let any school aligned with the Abyss. That’s because I want the Abyss to be this cosmology’s wild card. The true is that any Wizard can align with the Abyss and that the Abyss is probable the Plane (or Planar Rift) that is most “alive” (and hungry). Again, comparing this with the Malazan Book of the Fallen, the Abyss is my take on the Chaos Warrens. It gives your extra powers, servants or remove your limitations (maybe granting access to Antagonist Planar magic), but it will corrupt your physical form and open rifts on the Material Plane until it devours your world.
Domains: The High Form of Magic.
So we got our rival and potentially mad planar Wizards walking around. In this scenario came the Clerics. They wielded Domain-based magery, which they said to be “purer” and “safer” than the outsider-tainted powers of the crude Wizards.
The first Clerics originated from Wizards that pledged their abilities to a Deity. Deities are all powerful outsiders that reside within the Outer Planes and can affect the Material Plane (and Inner Planes) through their followers and summoned lesser outsiders.
Clerics could have their powers revoked by their Patron Deity, but they didn’t suffer any influence from the alien planar magic. Better yet, they could use their spells to summon outsider servants of their god (this would be a new ability: clerics can convert prepared spells to summon monsters aligned with their deity).
However, it didn’t took long for the greedy mortals to discover that the Deities themselves channeled their epic powers through Domains, strange nexus or planar conducts associated with primordial concepts located within the Astral Plane.
After this discovery, Clerics became independent from their Deities. Instead of following a god’s commands, a Cleric could bind himself to the spiritual purity demands of a particular set of Domains (usually two). This would be represented by selecting two Taboos (with one additional Taboo every three levels). A 1st-level Cleric with the War and Strength Domains could pick, for example, the following Taboos: 1) Never retreat from battle; and 2) Never takes order from a weaker individual. Domain-bound Cleric can’t spontaneously convert their prepared spells to summon divine servants (and also can’t cast planar ally or gate spells).
So now, Clerics can not only choose to serve a different god, but also Deities can’t remove a Cleric’s powers, only certain abilities. This means that the Gods must play a more subtle game of favors (and threats) with their followers and that Clerics can indeed be “bought” (or cajoled) by other Deities to “change sides” (or that an inept Deity can become a servant of its clergy). All that matters to these divine casters are the eternal Domains, not theirs “Masks” (the Deities).
Mystics: The Psionic Heresy.
And now we finally get to the final piece of this proto-cosmology: Psionics (or Mystics as I prefer to call them here). Mystics are seem by most civilized races and cultures as Abyss-spawn and heretics – masters of dangerous and dissolute doctrines, imbued with strange powers by the Things From Beyond the Outer Sphere (like the Abyss’ demons, qlippoths and worse things from the Dark Tapestry).
All this is a lie.
Mystics are truly deeply feared and hated… but by the Deities. That’s because all Deities were (in bygone ages and ancient worlds) Mystics themselves. While Wizards summon raw Planar power and Clerics channel the Domain’s aspects, Mystic focus inward. They are the ones that find the True Source of power within them. If properly fueled, this Inner Fire will – centuries in the future – give rise to a new God. And that’s why the current Deities desire to extinguish this knowledge. Outer Sphere’s divine politics are already too messed up.
That’s all folks!
This article is only a (potentially useless) example of how you can customize Pathfinder classes and setting to create a unique experience and a totally new way of seeing classic elements like Wizards and Clerics. You’ll note that I didn’t include other classes like Sorcerers and Druids. I just couldn’t find any good idea for them and a Pathfinder game doesn’t has to have all classes to work (I fact many seem to forget these days since Eberron’s design philosophy became mainstream).