"Hmm! That's something to think about. Maximizing total spell slots seems more useful for research where you know first thing in the morning what you're planning to work on today, but I didn't start this morning with anything resembling a plan and who knows when that'll change. Is there a formula for how many spell slots Arcanists lose? And why is that the tradeoff, are Arcanist scaffolds more fragile or prone to interfere with each other or something?"

"An arcanist can cast typically cast as many spells of a given circle as a wizard can, though a specialized wizard can usually eke out a bit more in their particular area. I haven't been able to figure out yet if this is intrinsic or a consequence of the fact that there are more wizards and thus there has been more collective brainpower spent on optimizing it, though my best guess is the latter since the scaffolding isn't that different. However, compared to someone who is both a sorcerer and a wizard they can cast fewer spells of a given level since they only have one source to draw upon compared to two, though they do benefit from not splitting their focus as much. In terms of a comparison between a sorcerer and an arcanist, an arcanist will have slightly fewer but more potent spells a day due to the differences between intuitive and formulaic casting, though what form that takes seems to be ideosyncratic and not wholly dependent on what sorcerous power source they draw upon."

"What would happen if someone drew on multiple sorcerous power sources?"

"A fascinating question. In the usual case, from the mixing of bloodlines this results in them obtaining a weaker form of all of the individual sources, but sometimes it results in one operating at full strength and some abilities from one or more other lines. If you use Nahyndrian power to splice the bloodline, both function at full strength but only sometimes stack when they overlap. I suspect the latter is closer to your own methodology, but I would need to examine it closer if I wanted to be certain. If you applied multiple Sorcerous powers to an Arcanist framework... this is entirely theoretical, but depending on the mechanism you might be end up manifesting multiple bloodline traits more strongly than high level arcanists usually do, having more energy to empower and cast spells with, or even be able to cast both reflexively and prepared spells of a given circle from the same pool of energy."

"Sounds like there's no reason not to find out empirically, then," she says with a grin. "What's Nahyndrian power, apart from 'in that dagger you made me' and 'very useful'?"

"I certainly can't think of one. I'll make sure to get you my notes on arcanism; in addition to the research I did, I should also have some more practical information like a copy of the Arcanamirium's textbooks and coursework somewhere or the diagramming I did of the differences between arcanist and wizarding scaffolding under arcane sight - it's not really a substitute for seeing it yourself, but it should at least give an idea of when you have it right. Do let me know if you end up trying it and deciding against it, though; sorcery wants splendor instead of intelligence like wizardry does, so you'll want a headband that does both that way. As for Nahyndrian crystals, it's a small bit of concentrated divine essence of a demon lord. I named them after the demon lord Nahyndri, since it was in his corpse that I first found them, but it turns out it generalizes to other ones so the name is a bit silly at this point."

"Textbooks and coursework would be super helpful, thank you! I really love this headband, by the way, it's amazing--does going Arcanist versus separate affect learning to make my own magic items one way or the other?"

"Only insofar as being able to do more or less things impacts how much time you have to dedicate to it; they require very similar skillsets. The main limiting factors on what magical items you can craft is your skill at spellcraft, which will improve with practice, your caster level, which increases with your normal spellcasting abilities, and what spells you can cast, of which I am not aware of any differences between wizards and arcanists since it's fairly trivial to turn the spellform for one into something usable by the other."

"Great! Speaking of turning spellforms into each other . . ." Brenda has some questions about which topological and energetic properties are conserved when doing different spellform manipulations! (It becomes clear halfway through the question that she's derived part of the process for preparing a spell at a higher than normal circle and wants to know how to tell what circles a spell can be heightened to by looking at it, but is missing a bunch of the vocabulary usually used to talk about it.)

It takes her a moment longer than it would have with more familiar terminology, but she’s more than skilled enough to pick up unfamiliar words on the fly. You can actually heighten a spell indefinitely by repeating the process; a third circle spell heightened to fourth can then be heightened again to fifth, as long as you were careful enough constructing it to make it fit together! As she explains, she draws in the air with her finger and a visual representation follows her finger, showing how you need to tie off the end of one level of heightening to properly connect it to the next, and how once you’ve practiced enough you can do it all in one mental motion without needing to pause. Every stable spell form can be heightened, but some of them are more useful than others; outside of the utility of being able to prepare or cast a spell more times in a day, heightened spells are usually most valuable for the kind of magic other people try and resist because the extra energy going into them directly translates into making that harder.

That's so neat! She's very curious about how resisting hostile magic works, on both a magical level and a psychological level. The existence of headbands and the matching buff spells--not to mention truth magic and mind-reading--must have such effects on the field of psychology, or at least they would if there was more widespread access to them and more of a systematized research paradigm.

Resisting spells is actually a few broad categories of actions that all get bundled together because they all get more difficult against stronger spells and all get easier to do for more powerful adventurers. It's typically split into three parts - willpower, fortitude, and reflexes - though there are a handful of spells like phantasm killer or shadow evocation that can blur the line between the categories. The second two have largely physical correlates - the reflexes needed to dodge enough to mitigate a fireball impact are related to those you need to dodge attacks and are both influenced by dexterity, while the bodily fortitude that helps you shrug off poison or disease or energy drain is related to how injured you can be before you're at risk of dying and both are influenced by constitution - but they aren't exactly the same thing, and unless they undergo special training experienced adventurers usually need magic or gear to get better at not being hit but naturally improve at avoiding area attacks. Willpower is something more of an odd duck, though; how resistant your mind and soul are to attack doesn't really have a physical correlate, and spellcasters tend to be better at it rather than specific kinds of martially inclined individuals. From the inside, rather than bracing yourself against an attack or moving out of the way, it tends to feel more like keeping hold of yourself and not permitting things to change except in ways you allow. Becoming more wise does still help it, though.

Her cloak and gloves should both help her at resisting magical effects, and the belt helps with fortitude, but to get more than that the easiest ways are morale based spells like heroism or adventuring.

The cloak and gloves and belt are very handy! It would be cool to find out if spellcasters are more resistant than martial types because of differences in the psychology of who becomes a spellcaster, or because something about handling lots of magic helps you learn to counter it.

The obvious guess is that it's about the magic, because it's true of almost every kind of caster from bards to clerics despite them having a wide array of different types of mental tendencies. One alternative theory that got proposed in the past was that you just needed to be exceptional in at least one mental domain, but remarkably intelligent swordsmen don't pick it up and wisdom is the only headband that seems to assist unless you're a paladin. There are admittedly some edge cases that give the theory problems, like rangers seeming to lack the trait even once they become able to use magic, but if the cause of this is known it hasn't ever been published and there isn't any compelling alternative explanation.

Maybe ranger magic is just really weird? But then rangers would be able to resist each other's spells especially well and everyone else would be especially bad at resisting rangers' spells and someone would probably have noticed.

No, they're actually not especially powerful divine casters. Which you'd think would explain it by itself, but that's also true of paladins and they have it, not to mention that a powerful ranger is stronger than a weak cleric but a weak cleric is still unusually resistant for their experience. Her best guess is that there's some underlying property that rangers happen to have that suppresses or redirects it, but it's not an especially satisfying answer and it she couldn't find anything when examining souls that seemed like a promising candidate.

What even are rangers anyway, like there's an extensional category but are they a fundamentally different thing from druids on the level of magic, they both seem to be getting their power from locations--

Brenda stops mid-sentence because she's realized she's being an idiot. Or possibly she was too scared to think of it before, but rightly or wrongly all the magic-nerding has shoved her fear into a corner.

"I just realized I've been ignoring the really important question. In all your research, have you learned anything other people don't know about how to close the Worldwound?"

"Nothing simple. I exploited a weakness in the planar boundary to tear the hole in the first place, but it's grown significantly since then and there are powers on the other side invested in keeping it open. The direct intervention of one of the greater gods would probably be enough, like it is for most things, but they all bind themselves to treaties and delicate balancing acts that prevent that and it would be costly even by their own standards; lesser interventions like calling forth a miracle have already been tried. By more mortal hands... well, I'm hardly so arrogant as to make confident pronouncements as to what Geb or Nex or Arazni are incapable of, but ordinary wishcraft wouldn't suffice unless you spent more than have ever been cast before on Golarion. Ritual magic is a bit more hopeful, but Lung Wa didn't manage it and none of its successors have a tenth its arcane might. If you wanted to manage it without assistance of that magnitude you'd either have to obtain that level of power yourself or destroy the keystone of the wound."

If she gets the option to befriend any of Nex, Geb, or Arazni she will take it. (Befriending Areelu Vorlesh is already helping via Anything You Can Do; her intuition for spell structures is noticeably better than it was before this conversation.)

"What's the keystone of the wound? Can it be destroyed with ordinary force or does it need to be " dropped in the fires of Mount Doom "magically unraveled somehow?" This isn't going to be as simple as her and her friends fighting their way to the center of the demon swarm, finding a giant rock, and smashing it, or someone would have done it already.

"That would be me. And I've certainly tried to make both those tasks difficult, but there's no such thing as a perfect set of defenses."

"Oh." 

There's a very obvious argument that killing one person to stop a war is worth it, especially when that person started the war in the first place, but she isn't going to respond with that even if it wouldn't make Areelu Vorlesh immediately and understandably try to kill her first. She trusted Brenda enough to say it.

"I guess I'll just have to become a legendary archmage or assemble history's greatest ritual instead, then." Is it insane of her not to feel like that's impossible and she should just give up? Fantasy novel logic says that it might take five million words but she'll get there eventually.

"I look forward to seeing it."

Brenda has a weirder Dumbledore/Obi-Wan/Merlin analogue situation than any she can recall reading about* but that's massively better than them fighting each other. She smiles.

"To that end--there was something the book I was reading was unclear about, are abjuration and transmutation and conjuration and so forth fundamentally different the way iron and copper and tin are different even if you can have an alloy with more than one, or is it more of a set of convenience categories like literary genres or snow versus sleet or something?"

*Harry Potter and the Methods of Rationality won't be published on Brenda's Earth for another four years and change.

"Somewhere in between. Most spells in a school share a large number of spell components with other spells in said school, and the skills of preparing or casting one typically cross over to others, but some of them fit better than others - particularly in necromancy, where past politics has played the largest role in classification, or the so-called universal school, which is simply a catchall for spells that don't neatly fit into one of the other categories. The Azlanti had an entirely separate categorization system for magic, and I wouldn't be surprised to hear that other worlds also did things very differently, but it's at least real enough that you can usually determine which school an unfamiliar spell falls into via detect magic and make useful predictions about what it will do or is capable of."

"That makes sense. I was wondering if teleportation and summoning being examples of conjuration meant that they were in some sense disassembling one's body and reassembling it at the destination, but if it's based on copiable structural elements maybe it doesn't mean anything."