Enchanting Living Things

He wants the moss to be the device. the effect appears to be eating away at the feet of those who walk upon it, for which PeCo seems reasonable.

Alternatively, you can try to extrapolate on the MuAn 25 guideline, granting a magical ability to an animal for an Herbam form.
However, since the moss is not intelligent nor even cunning, it has to be an constant effect not requiring any conscious effort to trigger it.

The reference to Gwidion is quite suitable since he enchanted a sapling. Gwidion did not seem to have any specific virtue or breakthrough to perform that, but it is the only example of enchanted living being I can remember. It can set a precedent for enchanting anything alive - like an animal, and I don't think that the base enchantment rules support that. Maybe a (minor ?) breakthrough should be required ?

Sure MoH has the example of a living plant being enchanted as a device. No examples of living animals being enchanted, except those bound as Familiars.

IIRC the item in question is a blackberry bush enchanted to be of immense size (well rather: spread out to cover en immense area, the branches and thorns etc seem to be normal sized) as well as having iron-hard thorns and branches. However there is no mention of how the plant grows while under the influence of the size-changing effect.

This is where Ars magic confuses me. The moss is the device, but isn't it also the target to be enchanted?

I don't see any problem enchanting living things besides the obvious strategical and logistical complications. Enchanting animals (or even humans) for example would only add some extra lab problems when dealing with non cooperative, maybe hostile and moving items to enchant. You would probably need some way to keep the target still, probably sleeping, and feed it somehow during the lab work. It would probably end heavily warped and the result would have the obvious problem of all living things: it will die, and end put the enchantment to an end, what makes them a waste of vis and time. That's why you don't enchant horses or grogs, but horseshoes, saddles, armors and weapons: they last longer, you can grab them from dead owners, and give them to new ones. But if any magus wants to enchant some living animal (or human) I'd say that flesh is probably worth 3 base points, as is bone, and a human of size +0 have a size multiplier of x5 straight from the size & form material, and extrapolate from there to other animals (let's say a horse of size +2 could end with a size multiplier of +7).

That being said, enchanting living plants would be pretty more useful: they will die, yeah, but trees that last for centuries are pretty common. And they grow!, so they can be a nice organic way to overcome size limitations in enchantments. I can see a magus enchanting seeds or nutshells, and then planting the seed, speeding it's growing a little bit, and end with some nice enchanted trees. Conceptually it would work... but the problem there would be that if wood is 2 Base Points and seeds are tiny and thus have a size multiplier of x1, then they would have pretty few room for enchantments. But then there wouldn't be any problem in planting the seeds and enchanting them when are the right size, let's say the size of a sword or a staff, to get a a x3 or x4 Size Multiplier, before they grow further. It would probably make a quite warped tree pretty soon, but warped enchantend trees seem possible, and warped plants seems less problematic than warped animals (or humans).

So to conclude I don't see any problem with it... but as your moss isn't expected to grow much more, you aren't going to get any benefits either. I mean, you could just enchant the stones from the ground to do the same. But if you want it to be moss then why not?

The moss is the item; the effect targets human bodies.

A sword with PeCo has bodies as the target of the effect. Now, if the effect is to make the sword sharper, then it is both the item and the target of a MuTe effect.

Another example: a wand enchanted to cast Pilums of Fire. Targets will be usually what the wand points. If you put the wand as the target of the pilums of fire, you'll only end with a big match.

Magically speaking the target of pilum of fire is the fire being created. Where that fire is being directed is a target in a different sense.

The moss is the device, the "enchantment" is the effect put into the device. When activated the effect affects the target.
Having said that, there are eaxmples where the device and the target are the same - this happens when the effect only affects the item itself, like a sword made sharp or an armour made indestructable.

Maybe the Pilum of Fire makes a bad example for its cosmetics. The fire isn't directed, as you don't need any Finesse roll to aim it. The effect is the fire being created. The target is where (or whom) the effect is created at, and that will take the burn, that is, what suffers the spell effect. And then the "fire being directed at" is just a cosmetic effect: there really isn't any fire coming from any wand or magus' hands.

Ok, I think I'm beginning to understand now. The moss may be where the enchantment is placed, but the target is whatever receives the effect of the spell. In this case, Corpus, because the effect is going to target whomever steps on the moss. This then leads to the next couple of questions:

  1. Should there be a requirement of Herbam because you are casting it on the moss?
  2. What about when animals step on the moss? Would you need a requirement for Animal as well?

Assuming that you can enchant the moss, here is one way of doing it.

  1. Herbam is not a requirement for enchantment. There is no requirement base on the material to be enchanted. There is no Terram requirement to enchant a gem or a iron sword. Same goes for any material.

  2. If you want to have a triggered effect, when preparing the main enchantment, the mage add +3 level for "triggered effect". Then, a second enchantment is placed, typically a detection enchantment (InCo, InAn - depending what the moss needs to target) which will triggered the main enchantment. The detection effect needs to be permanent (Sun duration, with environmental trigger, and 2 uses/day) since there is no trigger for the detection effect itself. When the detection spell detect something, it will trigger the main enchantment (Legend of Hermes: The Sunken Laboratory of Hermanus contains a lot of triggered effect and detection enchantments to be used as examples). This makes the moss an invested item, time and vis consuming.

  3. Because moss is not really highly enchantable - probably a base value of 2, it needs to be quite large to have enough room to handle both enchantments.

  1. No, as the answer above mentions. Creating an effect only requires the Tech + Form used to make the effect happen.
  2. Yes. If you want the moss to harm someone stepping on it it would be a PeCo effect for humanoids and PeAn for animal(-like bodies). A single effect doing both things would be PeCo(An) [Perdo Corpus with Animal requisite] or PeAn(Co) plus additional magnitude(s) for the added power of being able to affect two Forms.

I am reminded of enchanted items made of multiple parts - eg a talisman which is a wand with a gem on the end.
If you merely open the gem to enchantment, then the enchantment will fail if the gem is ever disconnected from the wand.

Moss, as a living thing, should be growing and changing. Eventually a significant amount of the moss will not be same as when it was enchanted (perhaps new twigs leaves, or old leaves fall off - at least the mossy equivalent), hence the enchantment should fail.

But if you can put a PeCo spell into a wooden wand, why not in any other static Herbem item?

It wouldn't necessarily fail. If you cast a ritual such that a group got +1 stamina, for example, the spell would not break when someone had a child, even though you could argue that the group had gotten larger. The child simply doesn't get the benefit. Similarly the new moss would not be enchanted, only the original amount.

If you are worried about the moss changing, couldn't you just cast a spell to stunt any future growth or keep it the same size/shape as it is at the time of the original enchantment? Or would that override the original enchantment?

Just realised I left out 5 words from my earlier post.

It is possible to enchant dynamic living things - see Longevity Potions and Familiars.
But LP tend to make the subject rather static (at least in terms of Aging). I am not clear about Familiars.

Perhaps if you can somehow give the moss an LP, so that it becomes more static, it might be easier to enchant?

Going off on a bit a tangent, It appears it is possible to make a plant into a Familiar, ala https://forum.atlas-games.com/t/familiar-plants/11298/1.
And https://forum.atlas-games.com/t/living-talismans/8309/1 suggests it is possible to turn a living plant into a Talisman. Though I understand that the Magi of Hermes book is not universally accepted as fully canon compatible.

Still, assuming that it is possible to turn a plant into either a Talisman or a Familiar, I keep wondering about turning a full grown tree (eg Oak) into either a Talisman or a Familiar.
Naturally this needs to be done in a laboratory, which means either moving the tree into the laboratory, or building a laboratory around the tree.
But if you manage to do that, just imagine the effects that you could enchant into the tree Familiar/Talisman - Free the Standing Tree ReHe30, and/or Stir the Slumbering Tree MuHe(Me) 25.

If the "Lord of the Rings" books have taught us anything, you want an Ent on your side during a Wizard War.

While re-reading "Guardians of the Forest", I noticed that in the section on treed of the forest, it mentions that if you enchant a whole tree, the shape & material bonuses are tripled. Therefore, the authors of GotF thought enchanting trees was acceptable.

Now, to create a Herbam specialist who rides around on his enchanted tree. Maybe have a very small lab in a treehouse to go with it?

He's in Magi of Hermes, isn't he?