Before bouncing this off to David directly, I figured I'd get the opinions of /start an argument here about the topic in question:
Fortunata's Treasures (p65) has a couple of item descriptions after it. The one in question is:
Maintain the Caster's Spell
(ReVi 45) base 30, +1 touch, +1 diam, 24/day
Effect: sustains a spell you have cast while you perform other actions - spell up to level 45
The problem I see here is it uses the item is the caster, not the magus. As such, would not the effect need a) voice range [to target a spell cast by someone else] and b) a different base effect, allowing it to maintain spells cast by someone else?
The end result should(?) be
(ReVi 45) Base 25, +2 voice, +1 diam, 24/day
Effect: sustains a spell in voice range - spell up to level 25
The base effect here results in (level +5 magnitues)/2 for the final spell level.
Am I missing something significant here? Advanced vimatics always make my head hurt.
You're absolutely right! And yet.
This effect is infact based off the guideline HoH, p. 129 top. (Level+2 magnitude, no divisor, meaning base 30 is correct).
It needs to indicate what type of magic it sustains (presumably Hermetic Mentem Magic?).
The range is a bit of a sore point with me personally, because here the Vim guidelines are inconsistant.
Appearantly only MuVi needs R:Voice to touch another caster's spell, because that discussion of range is in the MuVi box.
Personally, I'd prefer consistent Vim guidelines, but that's not what we have, so the wielder of the staff can simply touch the staff to the spell (???) and have it maintained.
EDIT: NB! It maintains spells up to level 40 (as it says in LoH), not level 45.
It works for talismans, but the maximum spell level should be 40 (base + 2 magnitudes).
No, it not a Muto Vim effect affecting the magic as it is cast.
If it's not a talisman, yes.
Actually the guideline is in the corebook (p.161), and it's not form specific.
It actually makes sense to a degree, as - like I said above - Muto Vim affects spells as they're being cast, before the magic reaches its target. Afterwards the effect is "present" and can be affected in itself.
Which of course raises the question if the range for this spell needs to be the range to the effect (you need to touch the target of the effect that you want to maintain) or to the caster (you need to touch the caster of the effect you want to maintain).
Ah ah ah! Compare the guidelines on p. 161 of ArM5 with the guideline on p. 129 HoH: S.
They both sustain a spell cast by someone else, but the one in HoH: S requires a type (Hermetic Terram magic is given as an example) and does not have a divisor. The version on p. 161 of the core book has a divisor, but sustains any spell. Compare Unravelling the Fabric of (Hermetic) [Form] (ArM5 p. 161) with Winds of Mundane Silence (again ArM5, p. 161). This spell would be legal if working by the guideline from HoH: S, but then it would need a type.
The original poster is completely correct in his calculations (as I recall), if te staff is to maintain any concentration based effect.
It does it does. To some extent.
It does raise some rather nasty other problems though, but mainly I want rules consistency.
That's one of the problems I mentioned above (and probably the worst one).
But aren't you already using the guideline from HoH: S here?
Talisman != You.
eg your talisman cannot use modify your spells using MuVi effects (without a specific mystery).
It is closely associated with you, but it is not fundamentally you.