I know you can defend directly against most spells. PeIg or ReIg to protect you against fire, a high Corpus score to add to your magic resistance against PeCo, a ReTe to quickly redirect a flying rock.
However, there is some precedent that states you can use spells to counteract the cosmetic effects of spells. Consider Frosty Breath of the Spoken Lie (InMe). In 4e, it used to have an Auram requisite. In 5e, the main purpose of the spell is to detect lies. The mist is a purely cosmetic effect and requires no requisite. However, the spell description clearly states that liars can fool the spell by using PeAu and ReAu spells to deal with the mist. Thus, by defending against the mist (a cosmetic effect), Magi can therefore ruin the spell itself.
Is this intended to be a precedent that can apply to other spells as well, or merely a bit of leftovers from 4e?
Some other examples: Mists of Change is a MuCo spell that randomly changes people into animals. The cosmetic effect is of a mist blanketing the valley, but the main part of the spell is MuCo. No Auram requisite is required. As an ST, would you allow a caster to use ReAu to deflect the mist elsewhere to protect a town?
There aren't a large variety of spells of this nature, but I'm wondering how you'd adjudicate Magi defending against the cosmetic effects on the grounds that if it's in the spell description, it's part of the spell.
Eep! I wasn't trying to be ungentlemany. I was just asking, really! I promise.
Regarding Pink Dot: I solved it in my game by asking players "Please don't abuse the Pink Dot Loophole." So far, no problems.
I strongly suspect the next thing we have to deal with re: Loopholes is Charged Items. I'm playing a Verditius, currently 12 years out of apprenticeship. I spent a season making an item that inflicts an Incapacitating Wound on an Individual, penetration total 70. Next season, I can have 13 of 'em. As one of my players put it: "You just killed Lord Marsyne or any Archmagus."
The -40 to your penetration granted by any aegis (or a divine aura if the SG is feeling naughty) can cripple your effect if it detracts from the story, though But yeah, quite a bad item there. Nobody has ever used a charged item IMS (only minor and major items for us, and permanent ones at that), so I am totally inexperienced in that area.
I'm going to start a new thread about Charged Items. This thread will contain spoilers for Castillo Occultos saga. Players in that saga (all one of them that reads the forum ) should absolutely not read this thread.
Mmm, i would allow it i think, but i might also then add that having such "flaws" included in a spell could be worth a reduction of a magnitude, or in extreme cases perhaps two, in spell level...
That would give a good reason for "flawed" spells to exist beyond fluff, as well as giving extra chances to fight the spell.
Just to clarify, I know this is a bit tangential, but as I understand it an Aegis does not reduce Penetration (in RAW). An incoming effect needs to Penetrate the level of the Aegis, but this doesn't cause the Penetration of the effect to be reduced. If I am a magus with a Magic Resistance of 20, standing in an Aegis of 40, then an incoming effect with a Penetration of 45 will bypass the Aegis (because 45 > 40) and then Penetrate me (because 45 > 20).
The protection provided by the Aegis does not stack with other sorts of Magic Resistance.
As far as the main point, of this thread, I think sure, if a defense targets the cosmetic effects of a spell, then that is a perfectly valid way to defeat it. A defense that stopped or diverted the mist of Mists of Change would be an excellent way to defend against the spell.
All true - but note that these are the rules for incoming effects. If I'm standing within the Aegis already, then my Casting Total is reduced by half the level of the Aegis; but as long as the Casting Total is still high enough the spell is otherwise unresisted by the Aegis. This is not technically a reduction to Penetration but has the same effect, on spells that are successfully cast at least.
Doesn't the Aegis also have to penetrate? It's a ward, and while Societates makes a point that both the Aegis and the Parma Magica are a different type of magic from other wards, by a strict reading of the rules all wards have to penetrate Magic Resistance to have an effect...
I believe the Aegis never has to penetrate under any circumstances. It's a Major Breakthrough and so not quite perfectly Hermetic. so it surpasses some Hermetic Limitations while also lacking some Hermetic benefits (being able to be cast at Ring duration, for example).
I'm usually a stickler for things like Penetration but Aegis is one place where I sweep that under the carpet. It does need to penetrate, but I'll err on the side of the story in cases where it isn't clear (i.e. I didn't work out the actual casting total / penetration at the time of casting).