I like that very much. (although IIRC -I just skimmed all of the line's muto vim spells last night- there is a spell from ancient magic for use after the caster has unlocked the secrets of Grigori magic that changes the sort of vis required for a spell and it is duration momentary)
Sounds good to me.
I would say it wouldn't be hard to issue errata for one or two problematic spells. That spell would need to be altered anyway using the current rules for a non-momentary ritual. So it's not like things are changing much vis-a-vis that spell.
I'm not a fan mostly because Wizard's Communion still get's screwed with. That can either be re-figured as a lower base effect to accommodate a greater duration or kept as is under the tried and true "doesn't follow the rules because it's an old Mercurian ritual". I could even see a custom duration called "Ritual" that is equivalent to diameter/concentration.
Does it really get messed up? Wizard's Communion can be used for non-ritual spell casting. In my experience, that's where it has been used the most since it allows a team, given a small extra bit of time, to give a nice boost to the penetration of a powerful spell. Meanwhile, many rituals don't need penetration (E.g. typical healing, stat boosting, and (depending on interpretation) Aegis of the Hearth). Also, generally speaking, though more tiring and requiring more time, ritual spell casting is easier than formulaic spell casting because you get to add both Artes Liberales and Philosophiae to your roll.
If you want to use it on rituals, just make a different version with D: Sun or (with more risk) D: Concentration. No big deal.
It's more of a history thing. In the in-game history as well as the out-of-game history WC has always been closely related to ritual casting. It seems to come from the Cult of Mercury Cooperative casting practices, and is a special ability of Mercurian Hermetics the go-to guys for ritual casting. If a Canonical change is made to MuVi then I would like to see the default WC stay consistent with that background.
Suffice to say that the spell is errata'ed:
- special duration at +0 magnitudes
"Being non hermetic, the duration of that spell suffice to cast any spell, ritual, ceremonial or not. It cannot affect spontaneous as normal.
This spell effect cannot be duplicated normally."
That solves things.
AS for the sigil spell, traces of magic may be one of the things vim is able to affect.
Thus it could be used either on a spell in creation, either on the remaining traces. The latter needs a duration as usual, but the former not.
Traces not being a spell, it's ok by rules.
The problem wizard's communion is that in previous editions it was used to cast a spell beyond the abilities of a caster from a text. In fifth edition casting tablets aren't as big of a deal as casting from texts was in prior editions so Wizard's Communion ended up being little more than a penetration enhancer with an increased botch chance. I've never particularly associated it with Aegis of the Hearth because Aegis of the hearth had never needed a high penetration prior to fifth edition (and it doesn't in my games now).
From the errata just posted
hardly 'just posted' but from the errata indeed.
And such excellent errata it is
Yeah, important after 2 editions of the Core, and one thing more, the other of the same book is interesting (addition of Martial Abilities on Failed Apprentice) too.
It just occurred to me that this is an unexpected benefit of the Flaw "Slow Caster" ... so much for your Wizard's War opponent's attempt to use Muto Vim on you
Well, the errata are "just posted"...
On the other hand so much for your allies being able to boost your spells .
Can we assume that the Wizards Communion that a character gets with the Mercurial Magic Virtue is a duration of Sun?
That sounds fair enough.
Considering the'yd then still have to get other magi to learn the same Dur:Sun version before it was worth anything, I think it's only fair.
One made to Ritual Spells with Duration: Sun can be Mastered with the Multiple casting option, to be casted on all (or many) of the Ritual Spell casted on the next hours, ideall to Mercurian magi and to Healers.
Erm, no. You cannot Target something that doesn't exists and Multiple Casting means you'd all cast them in the same round. Only if they were cast concurrently would it work.
How about those 2 edge cases?
- You don't have to cast WC at the start of the ritual.
- For a ritual spreading across noon or midnight, you must cast WC in the late part.
Well, the last sentence in the description of WC (p 160) states that "...it does not fit perfectly into the guidelines of Hermetic theory", so that alone invites SG's to rule as best fits their Troupe/Saga.