Spell Mechanics Questions

Hello! I'm new to Ars Magica and I'm gearing up to run a campaign for some folks who have never played AM either.

About Spell Mastery:

The description on pg. 86 of the Core Rules seems to suggest that the only way to learn/improve a Spell Mastery Ability is to study it from a book written specifically on that topic (not the spell itself but Mastery of it). This seems a bit odd because someone had to master it first before writing it down.

If there are other ways to learn this Ability per spell, what would they be (e.g. Adventure xp, Practice, etc.)?

Are books written specifically for increasing Spell Mastery, or would a book that was simply written on the spell be enough?

Please indicate if your answer is and official ruling or if it's an interpretation/house rule. Thanks in advance!

About Ceremonial Casting:

The example on pg.83 is a bit confusing. "However, if she gets lucky and rolls a 64 on the stress die, the spell will have a penetration of 12 (32, which is half of 64, minus the maximum spell level of 20) plus half her Technique + Form + Artes Liberales + Philosophiae + Stamina total."

My question is, why was the 64 halved? And, why is she only adding half her Technique?

p164, Practice, last bullet.
Also p165, Writing Books, 2nd para.

BTW, p86 does not forbid other means.

Spont is always half, p81.

Nice! Thank you.

I edited my original post with a 2nd question I had; I was trying to slip in in before a reply came :slight_smile:

Welcome to the game!

Worse, anyone who writes a book can only write a max Level of half their own level, so to write a Mastery 2 text would require someone know it at Mastery 4! :unamused: (Tractatus are possibly more common - see next section.)

But a mage can learn Mastery via any of the standard "Study Total" methods. A popular way is to claim "exposure" during a season, or whine to the SG and ask for partial exposure and partial X (other source). But Training/Teaching and specific Practice are also valid. (p 163-4)

First, there are no "books" - there are texts, and (in 5th ed) those fall into 3 basic categories: Summa (which have a max Level, and you can keep reading them until you reach that level), Tractatus (which you can only read once) (p 165), and "Lab Texts" (p 101-102), which have the step-by-step of how Spells and Enchanted Items can be made more easily. The first two have Qualities, which are the Study Total - that number = the number of experience for a Season of study.

For any Ability (aka "skill", of which Spell Mastery for any single spell is one Ability), you must read a Text (Summa or Tractatus) on that specific Spell. The only good news is that "Mastery" for any one spell is generic to teach/study/write about - if four magi read the same Text on Mastery of X Spell, each can learn a different "Mastery" from it. (p 87, mid page.)

She's not. She's adding half of her {Te+Fo+AL+Phil+Stam}. As with any Spont spell, as mentioned above.

Well, any spont spell where she exerts herself, if she uses non-fatiguing spontaneous magic she divides her (different ) total by 5.

As people before me have already mentioned Practice and Exposure - allow me to just contribute with Story Exp. Story exp granted for a story in which you've used a spell a lot, mey be put towards mastering it. I know I've done this a lot.

I suppose if you want to get all of the possibilities, in addition to practice exposure, story and texts there are training and teaching (and a few other unusual options in other books if you're a magical or faerie creature, if you're doing malfictum, you're stuck in an appropriate part of the twilight void, and so on)