Had an argument the other night on whether "counterspelling" had a different meaning to "dispelling". We were arguing about a canon character with a minor magical focus in dispelling.
I am reasonably certain that "counterspelling" and "dispelling" are different - my take is that counterspelling negates/interferes with magic as it is being cast, while dispelling negates/interferes with magic after it was cast.
But I am no longer clear if that is a valid distinction, or even a valid definition.
Is there anything definitive on this topic?
IMHO "counter-spelling" is interfering with magic in any way as it is being cast. And "dispelling" is removing magic, and I think I mean both magic already cast as well as magic being cast. Thus "dispelling" is somwehat a subset of "counter-spelling", which can either annull (Perdo most likely), deflect (Rego), block (Creo, to create some blocking medium) or change (Muto) the offensive magic being cast.
So the focus in dispelling would IMHO only apply to the type of counterspell which destrouys or annuls the target spell, not any of the other possible methods.
But I could also be convinced to buy the original poster's definition. Because dispelling a magical effect already there does not sound like counterspelling, so what would I have called that?
And I know of nothing in RAW to support or oppose any of the theories. But note that the text of Winds of Mundane Silence specifically can't be used against Momentary effects, but Unravelling the Fabric of [Form] lacks this limitation. And that the two use different guidelines.
From canon: Phillipus Niger in Guardians of the Forests has Dispelling as a minor focus from his mythic blood of Apromor.
The Followers of Pendule in HoH:Mystery Cults often learn a Major Magical Focus in counterspells. So from the canon of two wildly different books you get differences in the scope of the focus for two similar-sounding things.
But which spells in canon examples fall under the scope of the focus?
Checking Philipus Niger I see all his PeVi spells vary in casting total only by following the mastery scores. So the focus does not figure into any casting totals. I know magi in later books have the annotation "F" by casting totals which include a focus.
I think it depends a lot on what you mean with "counter spelling".
I would definitely allow a minor focus to encompass all Perdo Vim magics that can destroy spells/supernatural abilities/magical powers, whether activated before, after, or at the same time as whatever they are targeting (it's narrower than Perdo Vim, after all).
But a focus encompassing anything that interferes with other supernatural effects -- from an Aegis, to a Muto Vim spell designed to turn a Ball of Abysmal Fire into a harmless flash, from an Intellego spell allowing you to see through an illusion to a ReCo spell allowing you to dodge a Crystal Dart (or a MuCo spell allowing you to soak it better, or a PeTe spell to turn it to harmless dust)? I'd probably rank that as a Major Focus.
I agree that the definition of "counter-spelling" is difficult.
While I can accept your definition of "dispelling" being restricted to Perdo Vim, I would not have "counter-spelling" as broad as you suggest.
I would define "counter-spelling" as a spell that affected a specific casting of a spell, and the spell itself was the target of the counter-spelling. Basically either cancel the spell outright before it reaches its target, or modify the spell in such a way it does not deliver the same payload to its original target, and/or prevent/redirect it away from its original target.
Most of your examples I would classify as Fast-Cast defenses that won't prevent the original spell going off. And Aegis of the Hearth does not specifically target the spell, it is merely an environmental modifier.
(As I was writing that I am remembering some US Senate hearings from years back as the US DoD had to explain what they meant by "successful" test of anti-missile technology vs how safe the test target would still be if live warheads had been used. Apparently, like many large bureaucracies, they had redefined the parameters of "Successful" to make the results they were getting look good on paper. Or even Verizon and the current FCC on things like broadband deployment, broadband speed, and the effects of Net Neutrality. Sorry, off topic here, but it depresses me)
There's a lot of game-ism in how some Minor/Major magical Focuses get determined. My general guideline to to be more generous for major focuses than for minor ones, as a minor focus I view as more of a character 'accent', whereas a major focus is true core concept, especially as it takes your one major hermetic quality slot.
For example, I'd allow a minor magical focus in 'ghosts' or 'airy spirits' but not 'magical spirits' - there are multiple canon PCs with ghosts as a focus for example, so it'd be a little much to allow a strictly broader classification and still have it function as a minor magical focus. On the other hand, with a major magical focus in spirits I'd allow to not only encompass 'magical spirits', but naturally incorporeal fae - Faerie Jinn, for example - and most demons and angels as well. (Angels/devils/demons are described as 'nothing but souls' in ArM 5 core, I am not responsible for resulting angry Quaesitorial axe-squads or angry archangels or demonic princes should the magus attempt to actually use this aspect of the focus to mess with God/Demons, Arcane Limits still apply, etc.)
Philipus Niger's "dispelling" (minor) focus seems to apply to a wide variety of might-strippers across Realms per his statblock, which to me, felt a bit generous, but that could just be an issue with how I conceptualize the might-strippers. I'd totally give him it for Wind of Mundane Silence, The Heathen Witch Reborn, Shattering the Malicious Rune, which it seems perfectly aimed at, but I question whether stripping the might from magical creatures is 'dispelling' them. Still, it clearly seems intended, so I'll roll with it.
So to me, a Major Magical Focus that encompasses counterspelling would fully include the domain of dispelling, but also include spells like Mirror of Opposition, Supressing the Wizard's Handiwork which alter magic to bypass or change it against its original intent, rather than trying to destroy it. The subtle 'big one' here for 'counterspelling' as a Major Magical Focus is that it IMHO also generally includes any fast-cast spell defenses against magic. Which is pretty neat since it helps for really any TeFo.
You are right about Philipus Niger, his PeVi totals all seem to have the Focus added in, and IMHO it should only be relevant for spells affecting other spells/powers not Might Strippers.
It has been pointed out to me that the Children of Pralix, in the Ex Miscellanea chapter of H:H:Societas, get a free virtue Minor Magical Focus in Exotic Magic.
The description of this MMF is rather close to what I would refer to as Counter-spelling, though limited to the magic cast by non-Hermetic wizards.
Would it still be a Minor Magical Focus if:
a) was not limited to nonHermetic wizards?
b) was limited to Hermetic Magi?
a) A Focus in "metamagic" covering both Hermetic and exotic magic would suit me fine as Major
b) A Focus in "Hermetic metamagic" seems more useful to me than one in "exotic" however is a) allows a MMF to cover it all then "Hermetic only" as mMF must be ok...However one could also say a mMF would only cover "Hermetic counter-spells" (meaning fast cast defenses) OR "Rebuttal" (Re/MuVi like Wizard's Reach etc) OR "dispelling" (non-Fast Cast PeVi of existing spells) However this last alternative seems a bit weak. Maybe just splitting it in two, one for Fast-cast and one for not?
I had a quick look at these, and there is an aspect I am not clear on.
The example on HoH:S p129 suggests that a level 15 spell general spell with 2 levels of mastery, including Unraveling/Rebuttal causes the spell to act like it was level 21.
Does that mean that the spell is now a level 21 for casting purposes, or still level 15?
It could be important for a magus casting this mastered spell, if at the time of casting his casting total is, say, 18.
Would this magus automatically have a positive Penetration and require no Fatigue, or not?
IMHO this example means the spell is stil cast as lvl 15 for purposes of Fatigue, Penetration etc. But counts as lvl 21 regarding which spells it can affect. Unravelling spells have a roll of level+die+some modifier. The extra levels for Masteryx3 are also added, as it effectively raises level, for this purpuse only.