Since I'm trying to create some balance around this spell, rather than shooting down the player's idea entirely, what if the spell required a pawn of vis of the appropriate type, which serves as the receptacle for the siphoned vis?
Because Might is not raw vis in itself.
I don't see Perdo in it, because you don't destroy the vis - you change its nature from "being with Might" to "raw vis". I'd probably also put a Rego requisite in to transfer it out of the form of the being, making sure its not reabsorbed - so you'd need some sort of appropriate container at hand.
Sorry mate. I was trying to avoid turning it into a debate of the relative merits of might stripping. As I said early on, new players, not going to shoot down all their ideas. We're gonna try some of the corebook stuff first, and if we don't like the results, we'll evolve the game as needed.
In this case, the player didn't like the result (might stripping leaving no vis behind) and had a good in-game reason for wanting the spell at the time (a magic animal companion that is vis-dependent) so he wanted to know if another result (transferring the vis with rego rather than just destroying it with perdo) was possible.
After exploring the corebook and RoP books that I have further between sessions, I concluded no, but it might be possible with a hermetic breakthrough. So I picked up a copy of HoH:TL, which I think has the breakthrough rules (got all 3 HoH + RoP:F actually, it was a good day). Still reading those.
Given what breakthroughs can achieve in Ancient Magic, I don't think this breakthrough is all that bad. Its all in the usage, and will likely result in interesting stories.
I'm in total agreement there, but Auram is stated in ArM5 as the Form to use for incorporeality and this is what is followed in TMRE.
This specific thread (stealing the vis from creatures, preferbly lowering their might at the same time) pops up every ... half year or so?
My take: not going to happen - atleast not outside the laboratory.
In the lab? Look at Bind Magical Creatures (Major House Mystery of House VErditius, HoH: MC, p. 134-135)
Far enough. My apologies for running straight to the flak canons.
Entirely reasonable.
Er... yeah. Please, I beg you, do not use Ancient Magics as your yard stick.
Some of the stuff in there... shudder
Funny. I've only been running this game for 3 months, but bought the corebook and started reading/posting on the forums almost exactly... 6 months ago. You all should have seen this coming - doesn't anyone here have premonitions? =-O
Fair enough. I think I get most of the reasons why people wouldn't want this in their game. In addition to all the aforemmentioned problems, I've mentioned to the PC that if these spells become popular and widespread, it could lead to a decimation of the magical landscape akin to the near-extinction of the buffalo in 19th century America.
At the start, I talked up how powerful magi are, how versatile the magic system is, and how flexible and responsive the rules and setting are. I can hardly now shoot down every idea they come up with, and I prefer not to let my predjudices from other systems color my decisions. So unless I see obvious red flags (like yes, most of Ancient Magic, at least if used exactly as written - I still think there is a lot of story potential there and if the breakthrough is the culmination of a campaign rather than the start its not likely to break the setting in the short time its in use) I'm inclined to let them try stuff. It is after all what I (and the ArM5 rulebook) promised them.
Thanks. That's one I didn't know about. Looked at it, and, aside from this pc not being a Verditius (he's a gifted Mercere who got taken by a Boni during apprenticeship, and our cultist is a Criamon), its not exactly what I'm looking for.
I did find it odd that it states "magical creatures typically have some form of vis that collects in their corpse at death. This process does not use that vis; rather it uses the magical life force of the creature instead." Since might/5 = corpse vis, their certainly seems to be a relationship. Why would these be two different, unrelated things?
For my purposes, I think its better if its not a lab activity specifically. That will turn their thinking towards summoning creatures in the lab, safe from scrying eyes, just to kill them, exactly what we want to avoid. If its a spell, nothing prevents that, but they'll be more inclined to use it by going out and finding creatures, generating stories and posing risks of discovery and adverse consequence.
Far enough. My apologies for running straight to the flak canons.Entirely reasonable.
Er... yeah. Please, I beg you, do not use Ancient Magics as your yard stick.
Some of the stuff in there... shudder
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My regular group has an agreement that we won't summon/create things for Vis. Otherwise you get some ridiculous things happening:
- Summoning (need not be infernal, nor tainted) - Use scouring repeatedly, kill the spirits, take the Vis. Queens of Vis in a season with ease.
- Mercurian Magic and/or Imbued with the Spirit of (Form) - Create a group of elementals and destroy them for Vis. Queens of Vis in a season with ease. (It's a little harder but still works without those Virtues, too.)
- Bind Magical Creatures - Use the method described in #2 above to multiply the Vis you have manifold for enchanted items. Combine this with lesser enchanted devices and smelting and you can extract a lot of Vis for other purposes, too, and even essentially change one type of Vis to another. This isn't as quick as the methods above, but it allows for much greater flexibility of Vis.
Without this agreement we would probably have to house-rule something. But we figured it'd be too tricky to house-rule this stuff so we just agree to avoid such things. Much easier that way.
Chris
Ok, at the risk of facing the flak cannons again, here's my attempt to satisfy my player's interst in this forbidden topic.
How is this different from a Flambeau setting on a hunting expedition and looting lots and lots of magical animals in this magical forest yonder? As I see it, this kind of thing does not happen, because of several reasons:
a) Magi are rare enough and their vis needs low enough that for the most part, this is just not necessary. They can get the vis they need without destroying the local vis "ecology".
b) Magi are aware that overzealous harvest of raw a raw vis source - such as those magical wolves, say - will destroy it, which is over the long-term inferior to keeping on harvesting it at lower, sustainable, rates.
c) Magi are (vaguely) aware that overzealous harvesting of an aura will deplete and lower the aura, which is even worse, and may even constitute some sort of crime in some tribunals.
d) There are powerful Magical and supernatural beings that will be all over magi attempting to do this anyway. These include other magi (a la "Guardians of the Forest" or "Don't-Molest-The-Faeries" Merinitia), a Spirit of Magic, faerie lords, angels repulsed by the Greed this entails, and so on.
Whatever works for regular vis harvesting should generally work for spirits as well, but I still find it more problematic, because of the special nature of spirits.
i) Spirits are everywhere. Forget the Goetic Art of Scouring - just invent an InVi spell (or use Second Sight), and start targeting the airy spirits; summon the spirit of fire using your hearth as an arcane connection; summon an elemental... You don't need to go out and exploit the vis sources, the vis sources come to you. And that sucks.
ii) Spirits are tied to the features of the world. A hearth fire is a connection to a spirit of fire, a mountain has a spirit, so does a forest... So what happens when you render this spirit for raw vis? If this eliminates the material thing, or renders it mundane, this generally gives the magi too much power. If it doesn't, then the material-spirit connection appears vapid. Which sucks.
iii) Spirits are often immortal, or should be. I just don't think it's fun for a magus to be able to nonchalantly destroy an angel that has been around since the dawn of Creation.
So... I dislike Might stripping in general. But if might-stripping is kept, I don't see the harm in allowing regular beasties to be drained of raw vis instead of just stripped. I'd just make it a little harder - I would just require a Re(Pe)Vi spell, at one or a few magnitudes above the stripping guideline, and always higher than a "killer spell" - at least balance-wise, I don't think more is necessary. However, that only applies to corporeal forms. Against spirits, I would again say "just don't do it", but assuming that this isn't acceptable I'd urge you to:
i) Insist that lesser spirits - such as lowly airy spirits - cannot be usefully harvested at all. If Might/10 pawns of vis are harvested, you can just say that local airy spirits and things like "hearth-fire spirit" are of Magic Might 0-9, so that they cannot be harvested at all.
ii) Harvesting a spirit should be at least as difficult (high-level) as totally destroying or controlling the thing that it is a spirit-of. And the spirit still has the Form of that thing, even if it is incorporeal; it's not plain vanilla Vim. Harvesting generally depletes the target of magic, which may cause it to crumble or collapse or so on, or just to become more mundane. When affecting powerful spirits of places or their denziens (the dragon below the mountain, that sort of thing), it usually has adverse affects on the aura. This also means that commanding the spirit of the mountain to move over there, please, would require a ReVi(Te) spell equivalent in level to a ReVi spell to move it.
iii) Only the aspects of immortal spirits may be affected; such spirits truly reside in other Realms, and only send "aspects" to the world. This should, IMO, include all angels, demons, ghosts (that's what tartarus is for!), and of course daimons and saints (which is how these work, sorta, by RAW).
That's my 2c,
Yair
Bear in mind that soul =/= spirit. The soul goes on to it's final reward/punishment no matter what happens; the spirit remains behind for various shenanigans both of it's own and to be done to it.
That said, I'd rule you either kill it and then harvest vis or you strip is might and the vis is lost. You shouldn't be able to have it both ways.
Eric
Actually, this might provide an answer if we pay attention to a different part of the statement. The "vis collects at death." Thus it's not there prior to death. Meanwhile vis is not destroyed by the PeVi Might-stripping spells, but Might is. Since there is then less Might at death, there is less collection of vis. This amounts to vis being destroyed by the PeVi effects, but it is not the same.
With this interpretation there is no vis present to pull out of a body.
This does not create a conflict with Ablating because Ablating rips apart Might and converts it into any of a number of things. Vis is but one thing Ablating can convert it into. But that there is a conversion process prevents a conflict.
Chris
A sensible and wise agreement indeed!
As recall, this can be "economically viable" just by using T: Group.
I might be wrong though.
Just to be clear, in case it isn't: The dislike ain't with the existence of these spells, but with the ease with which one can destroy utterly the most powerful creatures of ME with them. It's so easy that, in most cases, this makes warding useless.
For exemple, while a Might 40 Dragon (supposedly a formidable creature), might, due to his soak, laugh at the 6 multicast PoF (CrIg 20) that penetrate his MR, he'll be short work for the 4 multicast lvl 05 DEO that do the same (2 rounds and he has no might pool. 3 rounds and, even if he survives, his Might Score is reduced to 20 forever. 4 rounds and he's dead).
Quick thoughts:
Mentem is not spelled Mentum. 
Less efficient than DEO - good.
I'd make the spell realm dependant, so that you'd need a version for Infernal Corpus, and another version for Faerie Corpus.
D: Momentary makes a mess when combined with the requirement for lab stabilization.
No, you're right. That's why I made the comment about it still working without those Virtues. The Virtues just make it easier.
Chris
Ah, I was just confusing myself then. 
For example, creating an elemental is a base of CrEl25 (El for element - Aq, Au, Ig, Te). Add 1 for R: Touch. When done with Aq this creates a Might 15 elemental at most, and for simplicity I'll just assume the rest are about the same. Each extra magnitude will add 5 more Might. I'll deal with T: Group in a moment.
Mercurian Magic: It's a wash at CrEl30, spending 3 Vis to get 3 Vis. However, a gain shows up at at CrEl40, with an investment of 4 Vis generating 5 Vis.
Imbued with the Spirit of Element: At CrEl30 and above spending 4 Fatigue (likely meaning unconsciousness) is required for a 1-Vis profit, and it doesn't help to use higher-level spells.
Both: A CrEl30 spell costs 3 Long-Term Fatigue (let's figure you Master it with Stalwart Casting), allowing you to stay conscious while generating 3 Vis per casting, meaning 1 Vis per day can be generated, or roughly a Queen in a season.
Including T: Group makes this all much better. There are material issues using the elements, so the gain from T:Group is actually greater with things like CrAn(Vi), but CrAn(Vi) has a base of 50. With elementals you need 10 times the material, so that's +1 magnitude right there. So, for example, CrEl45 would make ten Might 15 elementals.
Mercurian Magic: 5 Vis provide 30 Vis.
Imbued with the Spirit of Element: 4 Long-Term Fatigue and 6 Vis provide 30 Vis.
Both: 4 Long-Term Fatigue and 1 Vis provide 30 Vis.
Neither: 1 Long-Term Fatigue and 9 Vis provide 30 Vis. Even this can be done once per day to provide roughly 20 queens of Vis in a season.
Chris
I'm going to echo what manamar said, because I think that's an option that tends to get ignored...or at least, I never see it brought up in the might-stripper arguments.
But there's a difference between destroying a creature and killing it. If you destroy a creature with Might, using Demon's/Dragon's/Faerie's Eternal Oblivion (reducing its Might Pool to zero, and then eradicating its Might Score), then yes, that destroys any vis you hope to gain. But killing the creature leaves the vis behind and intact. You may have to use Gather the Essence of the Beast, but that's only a Level 15 ReVi, and anyone who's going to be running around slinging Eternal Oblivions should know that spell as well, especially if they intend on fetching vis on even a semi-regular basis. After all, this is what a lot of vis sources consist of.
While I don't dispute the calculations, I'd personally rule that no animal or thing can be created at a vis cost of less than its vis "worth". And that would include Creo Momentary Rituals, but also Rego summoning rituals. As you note, otherwise even plain CrAn(Vi) can get you into crazy-land.
That's the common problem with 1 magnitude = 10x scaling far too quickly. It should be 2x or 3x in a game more closely tied to a low fantasy setting.