familiar MR against a spell which you have MR mastery

Games Discussion Ars Magica
1

Hi.

Magus has a form resistance in Vim of 25. He has a PeVi spell (destroying magic might) with magic resistance mastery.

The familiar has 7 might.

An individual cast the PeVi spell (destroying magic might) against the familiar with 27 penetration.

What is the familiar MR against this spell?

  • 7 = its might. It is incorrect because ArM5DE p267 "the familiar uses the better of its magic reisstance or the magus's form resistance to resist spells, but this resistance does not stick with a parma magica".
  • 25 = the form resistance of the magus.
  • 50 = the form resistance of the magus, x2 due to the magic resistance mastery. (ArM5DE p225: "your magic resistance is doubled against the mastered spell,..." seem not appliable but under magic resistance (ArM5DE p221: "Hermetic magi have a base Magic Resistance equal to their score in the Form most applicable to the spell cast"). That quote seems to say that even when parma magica is not counted, form resistance = magic resistance, thus is affected by mastery, thus is appliable to familiar.

What is your answer?

Additional question 1: the familiar has the gift, is an hermetic magus, has "vim resistance" of score 15 which should raise its own MR against vim to 22. Speciliaty is "spell destroying might" which raise it to 23. And he also has learnt the "spell destroying might" cast against him, with a magic resistance mastery.
New options (if needed to play the question, we can decide to lower the form resistance of the magus to 5):

  • 30 =(might x2 + vim resistance (specialty)
  • 46 =(might + vim resistance (speciality)), x2

Additional question 2: Content of additional question 1 + the familiar also has a vim score of 10. He has no parma magica ability.

So new options:

  • 50 =(might + vim) x2 + vim resistance (specialty)
  • 66 =(might + vim resistance (specialty) + vim) x2

Obviously, the familiar is a Magical being.

What is your opinion?

Greetings,
Exar.

2

I'd go with 25.

3

I'll go with 25 MR as well for the first question.

If he Familiar is also Gifted, and Opened to Hermetic Magic, it's natural MR and the MR granted by Parma + Form are not cumulative, so it should have MR of 15 + PM * 5. And twice that against a spell it has learned and Mastered with the Spell Resistance Mastery.

4

I would say 50...

5

For the second part, I specifically made the gifted familiar not have parma magica because it would simplify the problem :D.

6

DE p411. MAGIC RESISTANCE: Magic Resistance is altered by the aura modifier. This includes Hermetic Magic Resistance due to the Parma Magica and Forms, as well as the resistance of creatures with supernatural Might. Thus, a magus in a Magic aura of 4 has a +4 bonus to his Magic Resistance, while a demon has a –4 penalty.

DE p412. CREATURE MAGIC RESISTANCE: Might Score + Aura Modifier

I'm of the opinion that the MR mastery would double the form MR & then modified by Aura modifier

About the scenario where the creature has the gift and has form MR of its own, I'm of the opinion that the higher resistance prevails and if removed with a Pe or Re Vi, the lesser one would assert itself.

W