Optimising for counter spelling

By counter-spelling, I mean interrupting the magical energies of a spell as it is being cast.

The only reference to this I know of is Arm5 p83 in a couple of paragraphs under Spontaneous Spells Fast Casting
There seems to be 3 requirements:

  1. Identify the spell being cast with a Perception + Awareness stress roll.
  2. Fast cast the counter in time, with a Quickness + Finesse stress roll.
  3. Actually generate a counter spell strong enough.

There is one sentence that I find is ambiguous

There doesn't seem to be any guidelines as to which TeFo to use in the fast cast defense. It almost sounds like you are supposed to use the same TeFo as the spell you are trying to counter, sort of like noise cancelling headphones do it by generating the same sound with an inverted wave phase.

  1. and 2) are pretty obvious how to optimise.
    However, what can be done to optimise 3) Actually generate a counter spell strong enough?

Could you have Special Circumstances - Fast cast magical defense?
What about Minor Magical Focus - Fast cast magical defense?
I say Minor Magical Focus as it seems to cover as much as Certamen, and probably used just as often.

Both your Special Circumstances and mMF look ok to me.

I think the intent of the "half level defender" was a Magus has a choice of Arts and fluffy description to use when they understand the attacking spell.

Ie. a CrIg jet of flame spell might be countered by PeIg, CrAq, CrTe, MuIg, ReIg, etc. subject to fluff which is based upon what the character learns from that important perception check.

Also - I've always wanted to see subtle or Deft Art as a way to prohibit another caster identifying your spells. They can't interpret what isn't there, the spell is in play before they can spont a defence, especially Mentem effects or spells which don't traverse the gap between the two casters.

A side question - can PeVi or ReVi be used as a more generic fast-cast defense against another spell? Thereby removing the need for step 1. Perdo to cancel or rego to suppress (was this in an old edition that I'm remembering?)

That might be back in ArM4, I didn't see anything obvious in the ArM5 Vim spell guidelines.

Fast caster is an obvious one.

Elementalist - most types of spell will fail if you can hide your body behind a load of earth/water/fire.
Life Linked Spontaneous Magic - guarantees that you have the power to pull off the spell
Self-Confident, that extra 3 to your roll can come in handy

Diedne Magic (if possible)

A really "out there" suggestion is "Ways of the Order" (based on Ways of the Land) 8)

If you house rule it to act like its name. Otherwise it's rather useless for fast casting. But Puissant Finesse would help. I've never really understood Fast Caster as written.

+3 to initiative to spells cast in combat.

If someone is casting a spell at you, it classes as combat.

I'll remember that, the next time I try to heal you, or use a ritual to increase eg your Intelligence or Stamina.

Sorry, let me clarify what I meant.

If you are casting a spell to counter someone elses spell, it should be classed as combat (magical combat)

I recommend you check out Ophelia Flambonis from Oppidum of Heviz PbP game. Marko also made a pretty good one with Roberto.

Yes. And by the book this makes it great for avoiding getting your spells countered.

But fast cast spells don't use initiative, they use "fast casting speed." And you can tell they're definitely different by the core book statement, "Note that, even in combat, this is not an Initiative Total." The core book agrees with you that this can be in combat and yet even with that agreement explicitly states this is not initiative. That's why many SGs house-rule that the Virtue also applies to fast casting speed.

Seems the forum at my post. Callen is, of course, quite correct about fast caster. The mechanical description is only a bonus for initiative. The flavor text says all your spell casting is faster. It isn't an unreasonable house rule to allow fast caster to assist with fast fast spells, otherwise it's a totally crappy virtue.

I believe it's officially listed somewhere in 5th that you can't do PeVi countermagic - the spell you're targeting has to be in existence in order to cast on it. However, that's not in the PeVi section, but I'm pretty sure it's in there somewhere.

You could use the "suppress all magic" or "suppress specific type of magic" guidelines of ReVi - although you run the risk of not suppressing it long enough.

Outside of that, "easy" ReVi countermagic isn't countermagic: it's Magic resistance (Aegis of the Hearth and Parma). That is - the techniques for preventing a spell from reaching its target exist in ReVi exist, but haven't been fully integrated yet, but it's understood that those two guidelines are ReVi in nature.

Another alternate defense is Sorcerer's Fork, which splits the penetration of a spell into 2 separate spells - perhaps enough to bounce off of one's Parma. (MuVi).

That being said, you can cast PeVi anti-magic wards to make a magically "dead" zone. (TME, pg. 109). Note that this was a change from concensus, as up to that point (I think) non-instant Perdo spells didn't seem to do stuff like that. I believe the authors have commented that this guideline "slipped past them", but it's canon now!

The core book says, "Magi often use Vim to counteract magical phenomena. Storyguides should assign spell levels for all magical phenomena that those using Vim counterspells will have to match."

Now I could see a solid argument against a single generic PeVi spell working because "In order to create a fast-cast defense against magic, a maga must know the Hermetic Form that governs that magic" would cease to be valid. But, even with such an argument, that statement remains valid for spells like Unraveling the Fabric of (Form).

I agree that Fast Caster should help with Quickness + Finesse stress roll. The wording of Lightning Reflexes does not seem applicable to the Quickness + Finesse stress roll.
Likewise Keen Vision and/or Sharp Ears should help with the Perception + Awareness stress roll.
This would be on top of the appropriate Affinity with [Ability] and Puissant [Ability] that would aid in maximising these rolls.
Could the skill Finesse have the specialisation (spell casting speed)?

Admittedly I was asking about how to disrupt a spell from being successfully cast, rather than blocking a successful casting.
However for blocking a spell, perhaps rather than Elementalist, have Flawless Magic and have the Fast Casting mastery for the spells Jupiter's Resounding Blow CrAu10, Flash of the Scarlet Flames CrIg15, or Seal the Earth CrTe10 to interfere with the casting Magus (there probably should be a similar CrAq spell).

Diedne Magic has its own issues.

But Ways of the Order? Surely you would have to have a lot of experience with magi of every House, and all the typical Covenant types. Perhaps a redcap could qualify for this, or a Quaesitor that spends all his time going everywhere.

It seems like most of these minor General Virtues that provide a bonus to skill use from a particular Ability, seem to provide a +3 bonus.

The worst thing is, I have just realised, is that in most cases the Fast Casting defense will have to be Fatiguing Spontaneous magic, in order to get a high enough Casting Total. Therefore you could only counterspell at most 5 spells in a battle.
Unless your defense is from formulaic spells that have been Mastered with the Fast Casting mastery.

Are you also considering to be able to counter powers and abilities from other traditions or even Realms ?
If it is the case, you would need to able to identify the power with Int+ Realm Lore, then cast the appropriate counterspell. In this case, you will have to spont'ed the counter spell since it is unlikely that your mage will know the exact counter spell considering the large number of powers available (Faerie Curse ? Faerie Entrancement ? Infernal Debauchery ?...).

Counter argument would be Wind of mundane Silence which can affect any spell regardless of Form or technique; and it would be one magnitude stronger as it would not need to be cast at T:Room.
A mastered fast-cast PeVi spell for defence seems very plausible (unless I'm missing some other factor).

I don't understand how that's a counter-argument. I said a generic PeVi spell might work (such as Wind of Mundane Silence). I showed the sentence that runs counter to anything generic working. Your counter-argument is that it's generic? I just don't follow.

How do you reconcile that with "In order to create a fast-cast defense against magic, a maga must know the Hermetic Form that governs that magic"?

I'm not saying it doesn't work. I'm just wondering about how the statements in the rules mesh as well as possible.

This can only be cast on spells which are still being cast.

Muto Vim spell
Target Your Caster
R:Voice, D:Diameter, T:individual
If the level of this spell -20 is greater or equal to the level of the target spell, this switches the target of the spell to the person casting it. The penetration on this spell must exceed the penetration of the targeted spell.
base, +2 Voice, +1 Diameter

If you master this variant of it for Fast Cast and maybe Penetration
Target Your Caster
MuVi 50
R:Voice, D:Diameter, T:individual
This works on formulaic spells up-to lvl 30 and switches the target of the spell to the person casting it. The penetration on this spell must exceed the penetration of the targeted spell.
base 35, +2 Voice, +1 Diameter

MuVI is a poor counter spelling choice, because, if the other spell caster isn't cooperating with you, you need to penetrate their resistance for the spell to take effect. Add to that the fast casting penalty of -10, means you need a lot of MuVi "juice" (high scores in both Arts) to overcome the penetration requirements of the TeFo combination.

Based on that requirement, and the fact that Rego and Perdo Vim spells do not have such a stipulation, I view that MuVi spells function while the spell is being worked, and that Rego and Perdo spells can affect the spell in the instant after that the spell has already been cast, but hasn't arrived at its intended target.

I miss read the quote and thought Winds was viable. You're correct