Magic Resistance Rego Targeting and Non-Mom duration

Ok so normally a spell has a targeting roll or magic resistance, depending on the spell.
For a Rego spell normally it ignores magic resistance, if it has a targetting roll right?

What about "Tangle of Wood and Thorns" Ars Magica Core pg 138?
It's a Rego Herban spell, with concentration duration. It has a targeting roll, so it could ignore magic resistance right? The thorns could wrap around, binding someone, but no puncture the skin right?

I think it should work like this:
Targetting roll to hit, then the target is bound.
Target takes damage if the spell penetrates - penetration needed because the wood is still under an effect
Then, regardless of penetration, if they struggle, they get hurt - no penetration because it is the targets movement, not the woods, that causes the damage.

Is that right?

Looks right to me.


Thanks One Shot

This actually took a lot of thinking about, due to all the old arguments about pink dots.
And I am not 100% certain.

I eventually thought of it in terms of Rego'ing a fiery catapult ammunition at some mage. eg pitch covered block of wood, set alight by mundane means.
Using ReHe to move the wooden block (which is covered in flaming pitch) at the magus.
The wooden block will stop without impact damage at the Parma Magica surrounding the magus, if the ReHe effect does not Penetrate.
However, the fiery aspect of the ammunition isn't being manipulated by magic, so PM shouldn't prevent the nearby fire burning anything it touches. And the mage should be able to reach out and touch the (flaming) pitch on the surface of the wooden block.
But what of any wooden splinters on the block?

And there is the fact it is a momentary effect. It should cease once the wooden block has reached the end of its trajectory (ie the magus's PM)
Therefore natural effects take over, it falls down, and may hit the mage's foot, not stopped by Parma Magica.

Rego-ing naturally burning stuff is another - different - case, isn't it? How are Wraithstalker's and your case in your opinion related?


Rereading my post, I think I made the mistake of suggesting a wooden block fully covered in flame. Whereas I meant a wooden block, with flaming points like thorns.
In "Tangle of Wood and Thorns" you use ReHe to move the thorn covered wood into damaging the target.
I was having difficulty with the thorns also being wood, and therefore potentially covered in ReHe. So in my analogy I turned the thorns into a different Form (flaming pitch) to help process

This is by design as opposed to a consequence. If you design a Rego spell to fling something and not keep controlling it to hit, then you don't get the automatic hit that many spells provide, so you make a targeting roll. Why would you do this? Because the magic no longer controls the thing, which means magic resistance won't help. Compare Wielding the Invisible Sling to The Invisible Sling of Vilano. This will always happen: if you don't use magic to guide something right into the target, you'll need a targeting roll. As a conditional statement in terms of magic resistance: if it avoids magic resistance, then you need a targeting roll (or similar like for an animated corpse swinging a knife via Brawl).

But conditional statements do not imply their converses. So this does not imply needing a targeting roll automatically bypassed magic resistance.

There are not a lot of cases like this by design. Usually, if you're going to need to penetrate, you probably want to avoid the targeting roll. But that doesn't mean no such spells exist at all. Let's look at this spell, Tangle of Wood and Thorns. You need a targeting roll, which is typical if you're going to have such a coordinated thing happening. Now what about magic resistance? Is the magic still active or is the wood entirely non-magical at this point? Societates specifically addresses this saying, "the wood does not have to touch a magus in order to immobilize him. The storyguide may choose to give a bonus to the Strength roll to escape." You get to avoid magic resistance if it doesn't touch the target, which may make it easier to escape. Notice that the spell needs to avoid touching the target to avoid the magic resistance. Why? Because it's still being controlled and so has to penetrate to touch the target. What's missing? It doesn't cause damage and it can't bind so tightly so it may be an easier thing to escape since those come from touching, which requires penetration. Really, a much clearer example comes right before that spell" Strike of the Angered Branch. That must hit the target violently or it simply won't do any damage since the damage is from striking violently. Again, the magic is still active, so it needs to penetrate to be effective at all. Unsurprisingly, this spell is left off of the HoH:S list of spells that can be at least partly effective if they don't penetrate (no proof since that list doesn't say it's exhaustive, but it is suggestive). Put more simply, if the rules for magic resistance say it needs to penetrate, then it needs to penetrate regardless of Finesse or similar rolls.

Yes, looks pretty good. You've got the wrapping not being resisted (much?) and no damage from the thorns because they are resistance. Escaping may or may not cause injury on the thorns, though, depending on the escape method and just how tight you rule the wood could get (reference the likely bonus to escape due to magic resistance).

Thanks for this discussion, I'm learning a lot.

This came up in my game on Monday, as it happens. Rather than stop while we debated it, I made a quick ruling that animated corpses are blocked by magic resistance because there's a constant Rego effect controlling them. My necromancer player was very annoyed at this and I'm worried that it was a bad call.

That is the correct call. However, a mundane sword wielded by an animated corpse does not need to penetrate.

Yeah, but also so would any improvised weapon, like a rock or something.

Would gauntlets or boots be enough to allow a corpse to connect a blow? I know the corpse itself couldn't touch, but would a 1cm or two of metal or leather be enough?

Well, canonically, putting a spear tip on a wooden pole that would need to penetrate is sufficient. But that would be more akin to a dagger. At some point you probably have to make a judgment call for when you cross over from only clothed and needing to penetrate to armed and not needing to penetrate. Is a shirt enough for the animated corpse to strike with its elbow unhindered by magic resistance? How about a bracer? How about a cestus? How about a katar?

How about throwing a bucket of paint over it?

This feels absurd; and it is, because we've started with two separate, perfectly sensible propositions and discovered that, in extremis, their implications are not coherent with one another.

I'm happy to handle this case-by-case during play, since it seems to me that any precise definition would feel unsatisfying.

In my troupe we ruled that magic resistance protects everything up to an inch of the skin.

So it means your MR protects your armor and your clothes from magic (it needs to penetrate your MR to affect it) but not your sword or your dagger.

In this case, a magical corpse with gauntlets wouldn't be able to touch a target protected by its MR.

realistically paint or cloth is not going to hurt anyone (or at least not damage them) at any degree of force, as either of these will give way before whatever they are striking. The fact that there is a parma-inhibited force driving it doesn't change that fact, except in ways that relate directly to the effects that can be stopped by parma.

How does this react with Target:Part? If I take (for example) a javelin or spear, and cast a Target: part spell to control the butt of the spear's haft to attack flawlessly with Rego... does that get magic resistance when the un-controlled tip stabs in? Thinking here of an 'invisible swordsman' ReFo spell that only controls the hilt of a weapon.


And if there's any doubt, I recommend favoring the defender, with PM resisting or not accordingly. I kind of just ask the little angel or spirit of the Parma, "Hey, do you want to resist this?" And if your ME cannot be viewed through that kind of animistic lens, then an Anselm-like construction of Parma awesomeness works too.

It's Mythic Europe, not FORTRAN.

Personally, I consider this a bigger problem than the famous "pink dot defence".


I wouldn't worry about it. I'd apply a -15 or so to the attack roll and a bunch of botch dice (if necessary), since the whole spear needs to be controlled.

I'd also advise the player about how this cleverness will play out way in advance.

EDIT: Oops, there is no attack roll. That lets me proceed straight to the botch dice as the spear flails around.



My inclination (coming from a point of wanting to enforce one of resistance or targetting rolls being required) would be to say that controlling a whole sword by using magic to move the hilt is no easier than controlling the sword using your hand, and that it therefore requires a finesse targetting roll.

That works too, which returns to the general original intent: A spell that affects someone requires targeting or resistance.