In the errata thread, @callen argued that the Adaptive Casting Spell Mastery Ability should be deleted.
HoH:TL p.99 and HoH:S p.34: I wrote a huge post about Adaptive Casting on the forums a long time ago. Short story: according to its description, it cannot work and should not exist. This is because there is only one Spell Mastery Ability for one spell according to the core rules, and this says they are different levels of the same spell. On top of that there comes a major lack of clarity of what happens when you've learned different Abilities, when you write about it, etc. as well as a lot of room for abuse. So just deleting the sentence doesn't really solve the problem. The easiest solution is to delete the entire option and consider it automatic with different levels of the same spell. If not, there probably need to be errata for core and at least one other book that does align with the core book on this issue.
There is a real problem here, because "general spell" is not really an in-game concept. DEO 25 and DEO 30 are different spells, just like PoF 20 and PoF 25 — we just don't have a general guideline for "create a fire doing level + 5 damage" (because that isn't exactly how the guidelines work…). It really is not clear which spells this ability should apply to. Do people have opinions on the best solution here? Errataing the ability out of existence is certainly the easiest solution, but that's not my question…
Fully defining "general spell" as an in-game concept is something that needs to be done.
How do handle things related to them in any given game is something that commonly comes up during pre-play table talk when working out "rules interpretations and house rules". Are books on Spell Mastery of a "general spell" for a specific level or all levels of a given spell. Keep all the Spell Mastery separate or merge then when Adaptive Casting is learned? Make the first Mastery for a "general spell" required to be Adaptive Casting so you only ever have one skill?
If anyone has the Virtue "Flawless Magic" then things can rapidly get difficult if they learn many "general spells". Personal experience here, we did not really hammer it out well in pre-play and it got painful to the point I forced the issue. We settled on books don't have level and merge when Adaptive Casting is learned. We also ruled that learning a new level of "general spell" gave my character 5XP in the Spell Mastery (Flawless Magic).
All that being said, I actually like having Adaptive Casting because it reduces the skill creep for what are spells with no real difference between them. So I am actually against errataing it out of existence. Making it the default for all "general spells" (rather than an actual Spell Mastery Ability) or making it the mandatory first Spell Mastery Ability are the direction I would lean towards.
EDIT: The part about keeping some version of Adaptive Casting is specifically in answer to if different levels of General Spells are treated as different spells and require different Spell Mastery abilities. Making Adaptive Casting the default (all General Spells use the same skill, no matter their level) would be my favored solution, with making Adaptive Casting the Mandatory first buy for a Spell Mastery in a General Spell (and resulting in only one skill) my second favored solution.
Huh??? You mean an in-character concept? There is certainly an in-game concept. There are a whole two paragraphs devoted to defining them on page 115.
I would argue there is an in-character concept, too. After all, the magi know two spells are both Aegis of the Hearth, just at different power levels. If they didn't recognize the simple power-level difference, why would they name them all the same thing?
But if it's not an in-character concept, then Adaptive Casting is ridiculous entirely because no one would ever know to develop it in the first place, nor to use it if they somehow got it (like from Twilight).
It's clearer than people think:
[the spell] may be learned at any level of difficulty — the higher the level, the more powerful the spell.
That is what the core book literally says what it means.
I do think it should be clarified. There is no difference between a guideline that says "general: +5 per magnitude", another guideline that says "base 5: +5" and "increase it by a magnitude for each additional +5," and "base 5: +5," "base 10: +10," "base 15: +15," etc.
Meanwhile, even the core book refers to all the many levels as different levels of a singular spell. A singular spell is only allowed to have a single Spell Mastery Ability. So technically, the core book had originally incorporated Adaptive Casting automatically. It wasn't until HoH:TL that a real mess came about.
"For the purposes of spell Mastery, two spells are the same if they have the same Arts, level, Range, Duration, Target, and effect; essentially if the game rule versions of the two spells are identical."
So, technically, the core book is entirely explicit that different levels of a general spell are not the same spell, for the purposes of spell Mastery. Adaptive Casting is reasonable on the surface, because the core rules do tend to talk about all versions of DEO as being "the same spell", but that, and the paragraphs on general spells, are artefacts of the way we (I) chose to present those rules, not fundamental features of either the game rules or the in-world metaphysics. Hence the problem.
Actually, Adaptive Casting increases skill creep. If it's errata'd out of existence, then there is only one Ability for all levels of a general spell. Adaptive Casting as-is added skill creep by saying there are many different Abilities for the same spell (even though it ruled itself out of existence by the core rules while doing so).
I see your point on that one. But it is still mixed because the game rules are actually identical for all those general spells. The problem with this sentence is that the first half and the last half are actually in disagreement.
I was referring that statement to David's position that DEO 20 and DEO 25 are different spells. If that is the path he chooses to take, then I would much rather have some version of Adaptive Casting and the ability to focus on only one Spell Mastery for all versions of a "general spell".
If you look my very next sentence you will see that I said I would rather make it the default (ie all levels of a general spell are a single spell) or failing that a mandatory buy.
This is where the enormous mess shows up. I've always tried to get a decision made by the troupe ahead of time. I've used the automatic first level you mention, too. I've also used others. Basically, there is no way of using Adaptive Casting without a mess unless you house rule it to behave differently. I think we agree there.
Oh we are in agreement on Adaptive Casting completely. Even the part of my post you disagreed with is actually in agreement with you. I just should have clarified that it was specifically to David's position that different levels of a "General Spell" are different spells. I'll clarify that so future confusion does not happen.
I just checked a little more thoroughly. You actually have more of a problem here than you thought. They have the same level, specifically called out as "General level" even before being written repeatedly "General." People learn the spell at different levels of effectiveness, but the spell itself only has the level known as "General."
Noting how much a mess Adaptive Casting is to deal with (i.e. you need to go back and edit a bunch of spots to explain how all sorts of things interact to get it working properly), my current suggestion would be to remove Adaptive Casting entirely, remove the "level," from p.87, and maybe add a sentence to p.87 that says one Spell Mastery Ability works for all levels of a General spell. This also helps make it so the Cult of Mercury isn't a near necessity for anyone who wants to be good at Spell Mastery.
If you want to keep Adaptive Casting, then in addition to editing it in HoH:TL and HoH:S so it's not the "same spell," there are a whole bunch of other interactions that are going to need to be explained revolving around books, teachers, Flawless Magic, etc. to make Adaptive Casting useable. I think Troy and I can probably point most of those out, but it will take a while.
Well for me the idea that there is but one Aegis of the Hearth Mastery Ability that covers all 'spells' known of it whether its level 10 or level 10000 makes perfect sense. I might even go further and say that a spell that does 5 damage and the same spell that does 7 damage are also the same and so one ability covers both.
I like there being some natural flexibility in spellcasting, including using a spell at lower potency then one's maximum for it. (So you have Aegis at 50, but you can also choose to cast it at 30 if you wanted to).
In the rules-as-written, you can only cast DEO at the level you invented it. I'm certainly not going to change that in errata… (It's explicit: ArM5 115.)
Spell Mastery is supposed to be something that most magi do not bother with, and that some magi learn for one or two (literally) spells that they want to do particular clever things with.
So, back to the topic of the thread. Despite callen's impressive rational reconstruction of the concept, General spells were simply a notational convenience, and there was never any deep theory about what made something a General spell. The closest equivalent that is actually defined in the rules is Similar Spells (page 101).
So, if Adaptive Casting were errata'd to apply to all Similar Spells, would that break anything?
(It also needs a note that you can only apply a single Spell Mastery to a single casting of a spell, even if you have multiple mastered Similar Spells all with Adaptive Casting. I can actually see use cases for that if someone has Flawless Magic — I can't see it being worth the time for anyone else.)
I think that would make things even more complex and even more requiring of adjudication at the table in individual use cases so would slow down games.
Personally I like the idea that all the formula-like guidelines be rewritten as general ones using the formula, if the intent was to have a maximum (to say the amount of damage a flame could do) there could be a max guideline level listed in the guideline. I also think it would save a bit of space that could be used for more guidelines from some of the supplements which many would like to see.
Would that also apply outside of the general spell and Adaptive Casting context? That is, would it prevent one from, say, both fast- and multi-casting a Pilum of Fire at the same time?
In that case, maybe tone it down a tad? Especially Multiple Casting.
Flawless Magic is perhaps the most powerful Major Hermetic Virtue for adventuring/combat magi (as opposed to lab rats), due to how useful Mastery is - which means it comes across as something everyone should do.
