Primus has mastered Ball of Abysmal Flame for magic resistance.
Secundus casts Pilum of Fire at Primus, which does not penetrate due to Primus's mastery because PoF is similar to BoAF (their primary effect is direct damage with fire, and they have the same range, duration, and target).
However, Secundus has Flexible Formulaic Magic, so he casts PoF again and changes the range from Voice to Sight.
Does Primus enjoy the protection of his mastery against the second PoF?
As a follow-up, would Primus keep his mastery's benefit against a PoF affected by Wizard's Boost?
Rules say that two spells are similar if either of the following are true:
Same effect, at a different Range, Duration, or Target. All three may differ.
Closely related effect, at the same Range, Duration, and Target.
PoF and BoAF have closely related effects and the same Range, Duration, and Target - and are thus considered similar.
PoF with range Sight does not have the same effect as a standard BoAF, and does not have the same range. So the two are not considered similar spells.
As for a PoF affected by a Wizard's Boost, it would depend on exactly how it was affected. The obvious effect would be to have it do extra damage, in which case it would still be considered similar to a BoAF.
The thrust of my question was, essentially, does FFM actually change the spell as far as the mastery is concerned. I can see arguments either way, though I think I'd come down on your side were it to become an issue in our troupe. I was wondering whether there were rules I wasn't aware of, and what the general opinion of the board (or those who were kind enough to respond) was.
I don't think it is ever spelled out explicitly in the rules, but I'd say that as regards magical defenses of various sorts (Magic Resistance, Counterspells, Dispelling, etc.) only the final result of the spell they act on is considered, not the base spell before any modifications from FFM, metamagic and the like.
I would say that's a smart use of Flexible Formulaic Magic, although how Primus figured out that Secundus was resisting his spell because he had a magic resistance ability on the spell mastery of his ball of abysmal flame is beyond me. Ultimately, magic resistance in spell mastery works the same way as determining what is similar in the lab. If you don't like how it works, you're in house rule and troupe interpretation territory.
And yes, spell mastery on a spell boosted with a muto vim effect applies, I believe. I would globally say that the spell mastery applies before any muto vim effect applies, and yes, incidentally you could get arround a spell mastery's magic resistance specialty by muto vim into a slightly different spell.
That is a bit confusingly worded since spell mastery can apply for both caster and target.
My interpretation of the rules, which I think matches yours, is that for the caster of a spell, his Spell Mastery applies to the spell cast even if the spell is modified by FFM or MuVi metamagic.
If the target has the Spell Mastery special ability Magic Resistance it applies only if the end result (after modifications for FFM or MuVi effects) is similar to the mastered spell.
FFM and MuVi do not necessarily apply to spells the same way vis-a-vis Mastery. For MuVi, you cast the MuVi. Then you cast the spell normally, at its normal R/D/T and at its normal level; that spell is identical to the one you mastered. For FFM you alter the actual spell being cast; the spell being cast has a different R/D/T than the original and is cast at a different level. It would seem hard to argue you couldn't use your Mastery on the MuVi-altered one, using your mastery on the FFM-altered one could easily be ruled differently. There should probably be a note about Spell Mastery in the FFM description.
As for the original resistance question, because one makes a ball and one makes a jet, they're not technically the same effect. However, we could invent a CrIg spell Pilum of Flame that uses the same R/D/T and does level-5 damage. Now the game rules say they are the same effect, so varying R/D/T of one would keep it similar to the other. That's what I don't love about this particular case. They're extremely close to being the same effect, especially when compared to turning someone into a mouse versus turning someone into a bear. So I could well see troupes ruling in either direction, which is what the core rules say "This is, ultimately, a judgment call on the part of the troupe."
I'd say that ball vs jet is a mainly cosmetic difference. YSMV on that.
The real difference between PoF and BoAF is that they do different amounts of damage. That makes them not the same effect.
That would make DEO 20 and DEO 25 not "the same effect." But the both follow the same rule "the demon loses Might Score equal to the spell’s level." According to the definition of similar spells, "Two spells have the same effect if the rules description of the spell is the same," which they do. So, at least by the core book, the different amount of damage does not imply it's not "the same effect." But these (PoF and BoAF) weren't written with calculations in them like my alternative above, which would be the way to cite what you're citing.
So if I reformulate my statement as "The real difference between PoF and BoAF is that they are described as doing different amounts of damage. That makes them not the same effect.", would that make you happier with it?
Callen is referencing that damaging spells with an easy function could (and maybe should) be written as general guidelines. More damage being merely a higher level effect of the same guideline as would be he case with DEO.
Magus A has mastered a Voice-ranged spell (level 30) to take down Parma Magica, choosing Resistance. Magus B has a Sight-ranged spell (level 30) to take down Parma Magica.
Would you say it's reasonable for Magus A's Resistance not to apply to Magus B's attack? If not, then why are being so picky about guidelines that are written as
general, +5 per magnitude v.
base 5 for +5 and then +5 for each additional magnitude v.
base 5 for +5, base 10 for +10, base 15 for +15, etc.?
Basically we're saying what is so incredibly important in the world is the notation an author chose to write the same formula?
This has essentially happened in the real world with quantum mechanics. It wasn't that the different formulas represented different real-world things. It was just that we didn't recognize the different formulas were saying the same things in different ways.
I think its a bit early to say exactly what has happened with our understanding of quantum mechanics, given the rate at which changes and reconsiderations of the model continue to happen.
I'm referring to Heisenberg's matrix mechanic v. Schrodinger's wave mechanics, which were done within a year of each other. Both seemed to work properly, but they seemed totally different. People were confused. It took a good portion of a year after Schrodinger's wave mechanics came out for Schrodinger to prove the two formulations were actually equivalent. No, it is certainly not too early to know this. We proved that mathematical equivalence between the two formulations almost a century ago.