Question about Sorceror's Fork

[Monkoflords]

A player of mine had a question about Sorceror's Fork I wasn't sure about, so I decided to ask here.

He was curious about using it on an enemy's spell, and the effects it would have. I know the book says all of the split spells would hit a single target, so I know that much.

1. Would this affect the penetration at all? Or would all the spells share the original spells penetration?
2. If the mage cast on is not cooperating, would there be anything else the spellcaster of Sorceror's Fork have to do to split the spell?
3. Is there any real benefit for splitting an opposing mages spell to weaken it?

Just trying to clear things up for him, thank you!

[Jonathan.Link]

@Monkoflords

2. If the mage cast on is not cooperating, would there be anything else the spellcaster of Sorceror's Fork have to do to split the spell?

Answering the 2nd question, first. Using it on an enemy spell isn't easy. You need to be a real MuVi Prodigy and have the spell mastered for fast casting.

@Ars Magica 5th Edition

If you wish to cast one of these spells on a spell being cast by another magus, you must either be cooperating, or you must fast cast the MuVi spell. There is no other way to get the timing right. In addition, your Penetration total for the Muto Vim spell must beat the other magus’s Penetration total for the spell to be changed, unless you are cooperating.

@Monkoflords

1. Would this affect the penetration at all? Or would all the spells share the original spells penetration?

That's not explicitly stated anywhere. My feeling is that the new spell that was split would have a penetration score based on the Muto Vim spell. But I can see penetration being evenly divided based on the original spell, too. I think both or reasonable, and I'm sure that there are some other ways to handle it, too.

@Monkoflords

3. Is there any real benefit for splitting an opposing mages spell to weaken it?

Probably not. Unless the character has a focus in Metamagic or something, it's probably easier to master the PeVi spells that can shut down the magic. They don't have to penetrate a casting total like MuVi spells and are of much lower level. It still requires someone who has a high Vim score to do it reliably when you take -10 off the casting total right off the bast (because of fast casting).

[KevinSchultz]

The rule for penetration is in the description of the spell.

@Ars Magica

Each resulting spell has the same range, dudration, and target (target category, that is - the actual target may be different)...The precise effect is at story guide discretion. One casting die is rolled, and the Penetration total is split between the spells.

I think what you're asking is "what occurs when a spell is split, but hit the same target?" As I read that, the first clause suggests that the actual target may be different...or it may be the same. Therefore, the second ruling, of "one roll, penetration split" is applied universally, regardless of what or how many targets there are.

In fact, when I first read this, I thought this was the POINT of the spell - to fast-cast the effect so that your enemy's spell couldn't penetrate your Parma. Then I realized (and it could very well have been a conversation with Jonathan.Link) that was probably needlessly complex as a defense, unless you were a serious Muto Vim aficionado.