Weird Spell / Mechanics Question

If a mage casts a spell on you to turn you into a planarian flatworm for an extended period of time and cuts you in half having you grow into two different worms. What happens when the spell ends assuming the mage fed and kept both worms alive?

While this is probably the least interesting answer you could hope for, I suspect "planarians don't work the same (or maybe even exist) in Mythic Europe" features highly. For instance, their regeneration/replication might be supernatural, in which case it wouldn't apply to a human transformed as such.

More generally, I'd rule that the larger piece (or just one, by random determination, if cut exactly in half, say) is the only one that turns back, injured if the regeneration hasn't fully done its work yet, whole if it has. The rest dies or disappears or just stays as flatworms, idk. There's only one soul in the equation, and the others turning into empty vessel bodies would probably violate Creo rules and be used to mass-produce meat or something.


I figured as much, its that deciding outcomes between dies or disappears or just stays as flatworms that interests me the most. Obviously in a game this is up to the SG but I was just curious how other people would rule it.

My wife suggested a possible outcome of each worm turning into the respective halves of your body as the body mass from the rest of the healed and fed flatworm couldn't make up for the rest of the body so you'd probably be dead but each half would be healed over on the cuts.

Probably not what any SG would want to rule it as but it's a fun thought.

Depending on your SG you might have also created a faerie duplicate who will make no end of trouble for you in order to generate stories so it can feed.


Depending on the game, the bloody mess of two halves might be most likely.
Or, one body gets the soul, the other becomes a husk or dies.
Or, the soul IS split in half, and you have two half-alive human clones.
Maybe you get two creatures inhabited by demons, spirits, or faeries.


Considering that most of the organs which sustain life and define u as people are in the head and upper torso it seems obvious to me that the head portion should remain the person upon whom this experiment was performed (if an NPC likely earning a lot of animosity towards the cruel mages as well) before the experiment is performed there should be absolutely no sense of certainty that it is survivable, barring perhaps experiments with other animals. Either demons or faeries will likely conceal their true nature and try to act like an actual duplicate of the person when examined, their nature only becoming evident through difficult arcane research or by long term covert observation of their activities.
Remember that if performed within the covenant this experiment could be considered a method of summoning whatever animates the inhuman half, which would therefore be considered invited per the rules for the aegis.

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A planarian could be split vertically in half, and it would still regenerate. In that case there's no upper torso to retain the head (and soul).

I'd be more concerned with the following: given a planarian flatworm unique regenerative capability, when a grog lose a limb, turn him into one with a Moon spell, keep him alive and upon becoming human again his limb should have grown back.

Even, if the grog was decapitated and you could transfrom the head just before life ends (assuming there is at least a small delay), in about 3 weeks you could have him back alive (and well???).

So, very powerful healing with no vis expenditure.

I'd do something to curb this (I have no idea of what exactly without thinking a bit more about the issue), and probably the decision on how to curb the exploit would also give an answer to the original question.

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It's highly likely that in Mythic Europe a planarian's unique regenerative abilities would be a supernatural effect, and humans transformed into other beings with Hermetic magic don't generally gain abilities not associated with the physical form. For instance, a person turned into the shape of a wurm (spelling? Noble's Parma) would have its fangs and constriction capabilities, but probably not its magical venom or entrancing gaze, as those things are Powers. A human Hermetically turned into a unicorn could run or fly as such, but probably not detect moral purity or heal people with a touch of their horn. While planarians aren't supernatural creatures in real life (obviously), by Ars Magica standards the capacity to regenerate fully when cut in half would certainly be closer to a Power than a mere animal trait. Planarians would likely be very low-Might Magic creatures.

That said, I have broached a similar topic with this forum before, regarding whether it'd be possible to use Muto Corpus to give a human the unnatural ability to regrow limbs/eyes/whatnot, then if the effect lasts long enough, they start gradually recovering from the limb loss as if it were a Heavy Wound - essentially, whether you could use the body's healing process over time to get around the vis cost of Ritual restoration, sorta like how you can give somebody a Recovery bonus for free even though you need vis to heal them all at once.

Personally, I think either the planarian method or the MuCo method WOULD work... UNLESS the impediment/injury is represented by a Flaw. If a character has a hand withered off by a Perdo Corpus effect, then I'd personally allow such an approach to treat them. However, Virtues and Flaws are different, not just as a game mechanics term but within the fabric of Ars Magica's metaphysics, because they're part of your Essential Nature, and therefore runs up against the Hermetic Limit thereof. I would argue that if it's part of your Essential Nature to be missing a hand (as dictated by possession of the Missing Hand Flaw), even if you give yourself the ability to regrow it with Muto Corpus, it will wither back to a stump the moment the Muto Corpus effect's duration expires. Same thing for planarian-based regen.


If a human missing their right hand were transformed into a dog the dog would be missing it's right forepaw. Is there an equivalent organ for the planarian to be missing? The more essential question would likely be when and where planarians were discovered. After all if it is unknown in Europe at the time it simply would ot even exist in Ars magica. The next question is, if it was known to exist what properties was it believed to have had and what was its nature believed to be.

With a bit of research, Planerians were native to asia and unknown in Europe until the late 18th century, so in AM they simply do not exist.