Hi,
How did that work?
I am (possibly to be played here) writing up a character with some similarities (FM, for example), but I didn't think through MuVi as fully, and was considering a few strategic formulaic MuVi spells. My cleverness is a bit different, using faerie sympathy to in certain circumstances increase mastery abilities (sympathy adds to the score, not the roll! the score then affects all sorts of things) as well as some more obvious uses.
Anyway,
Ken
The focus in cooking allowed her to start with several very high level Rego spells for cooking, doing it as Craft Magic instead of just creation. Since she was very good at Finesse she could make Excellent (see C&G) food, and the standard example for a single food is a bonus to aging rolls, but we had this apply to the whole meal. We also applied the limit strictly, based on Craft: Baking or Craft: Cooking or etc.
She also had an applicable Faerie Sympathy. I believe she had two: one with Dionysus for wine and a broader one (see Faerie Sympathy rules) for food and beverages. I believe she also had Cautious with Finesse. Just preparing meals for our own covenant and making the wine she was selling required something like 4 Finesse rolls per day. That's 1460 rolls in a year. Even without Cautious with Finesse, Faerie Sympathies tend to advance about 1 experience per 10 rolls because 1's are far more common that botches, and it's even more true with botch die reductions such as Cautious with Finesse or the mastery option for Finesse. So she would gain something like 160 experience per year in Faerie Sympathy from a few minutes per day from feeding our covenant alone. (This is uncapped by Warping due to the method of acquisition.) When she would have started selling the food that would have increased dramatically.
Now, sure, it sounds like she can get a ridiculously high Finesse roll for no good. However, the Faerie Sympathy also applies as a specialty to the Craft Abilities. So we started doing the math. After ten years or so (about when longevity rituals would have been needed) she would have had effective Sympathy/Craft scores around 60, meaning +20 to aging rolls (and without fertility problems). And that's without extra rolls for making more food or wine for covenants throughout Europe, just making it for her own covenant.
Even with the yearly Warping we figured it would cause for being a sort of Faerie food, it got so much better than longevity rituals so quickly. Plus, it would stack with longevity rituals. But even without the stacking, it just got gross. And yet she was generally speaking the weakest member of the covenant. I retired her shortly after the calculation and the realization of what that would do to the Hermetic world.
Bottom line: Faerie Sympathy when mixed with spells can explode out of control as written.
Yes, it applies to the Mastery Ability - probably not granting more options, but still reducing botch dice and adding to the casting total. It also applies to Finesse rolls and to Penetration. It also applies to Magic Theory to invent the spells. That makes it easy to Multiple Cast a huge number of spells. I designed a magus out of gauntlet with a Minor Magical Focus in lightning and a Faerie Sympathy in Thunder and Lightning (TSE) who could multiple cast something like 12 copies of Incantation of Lightning with penetrations somewhere around 35 each, depending on the rolls. See the bottom line above...
This is why I stuck with what Mark said about not using so many tricks from all over the place with this character:
Affinity w/ Magic Theory, Affinity w/ Parma Magica, Affinity w/ Vim, Cautious Sorcerer, Deft Vim, Flawless Magic, The Gift, Hermetic Magus, Independent Study, Minor Magical Focus: manipulating his own spells, Skilled Parens (Knights of Seneca)
This is compared to Valentino before who had Imbued with the Spirit of Corpus and Mercurian Magic. This time everything is straight out of ArM5 itself outside of one Minor Flaw (which is reasonable bad) and a couple spells (ArM5 guidelines but written in other books, not made up myself). I still may drop the Minor Magical Focus. I'm torn. I'm not sure he's going to have to spont a MuVi spell above level 20, and he can pretty much do 10 right out of gauntlet without the focus. I suspect Affinity w/ Vim will accomplish most of what he needs.
Are you sure the bonus to aging rolls would stack? I would think mundane food, even excellent food, would give at most a +3 bonus to any given aging roll. Plus I would imagine the character would be really boring to play, because she's basically in the kitchen all the time (I would abstract this down to only a few rolls a season). Didn't she have any ambition beyond feeding the covenant? I would imagine her sympathy with faerie should have brought lots of faerie-themed stories, too.
Hi,
I didn't even consider all the xps, which is definitely a problem. But I also don't see how you get a total of 60. 160xp/year becomes a sympathy score of 20, which is huge but the only thing added to Finesse, so after the roll I see a total around 35. Hmm. That's still as good as a decent LP, and if you don't apply warping (I wouldn't), a great alternative.
In my usual tradition of offering rules alternatives, I'd probably rewrite Faerie Sympathy as follows (though probably not for this saga, unless Marko wants it):
Minor Virtue: Choose an appropriate positive sympathy equivalent in scope to a minor focus or special circumstance. Your score in that sympathy equals your warping score. You may increase your Warping score during character creation. You must have (strong) faerie blood to take this.
Free Virtue: Chose one positive and one negative sympathy as above. Your score in each equals your Warping score.... as above.
Major Virtue: Like the minor virtue, but scoped like a major focus or much wider circumstance or theme.
Minor Flaw: etc. ...
(strong) Faerie Blood: Instead of a special power, you can choose an appropriate minor positive sympathy. This makes it very easy to create new kinds of Faerie Blood. Note that you can be touched by faerie late in life, and get this virtue. (Come to think of it, I like the idea of using this as the standard rule for all fairy blood! Much cooler than +1 to a characteristic, for example.)
Faerie Legacy: You can swap your minor faerie blood sympathy for a major sympathy.
On the positive side, no xp investment is required or allowed. But having a high sympathy requires a high Warping score, so the virtues come with a very large penalty built in. To make it all work, using a sympathy would still require a stress roll, but no longer cause Warping.
Tangentially,
Ken
The intention is that Sympathy Traits apply to mundane activities, making them magical (er, fay, rather). The rules say no supernatural abilities, but I would certainly support extending that to arcane abilities that are only used with non-faerie powers. It could work like this: you try to use your sympathy with the ability, which temporarily changes it into a faerie-flavored Supernatural Ability, and suddenly it doesn't work with Hermetic magic any more.
I wrote 10 years, not 1 year. We had some years before needed longevity rituals, roughly 10 years as it was.
This is essentially just Faerie Blood: Faerie God.
Yes, that's probably a lot more workable that what's in RoP:F. Though RoP:F isn't so bad when not combined with spells. It's the combination with spells that makes things go nuts.
Yes, something like that works, too, and it's probably easier.
the rules explicitly allow sympathies to apply to magic
They also explicitly are not set equal to Warping Score. I'm pretty sure this was Mercuria's alternate suggestion to yours about how to keep the explosion problem I mentioned under control.
1600xp --> Ability around 20
Yes, with the ambiguity removed.
It has interesting effects elsewhere too. The nastiest imo is what happens to social abilities; Jedi mind trick with no need to penetrate for the win. Alchemy is fun too. Non-hermetic magic with totals that include a mundane ability become interesting. Binding sympathy directly to Warping keeps it powerful, as it should be, but there becomes a real price for having a good sympathy, and the scores stay lower. Hermetic Magi can be extremely powerful anyway, from a Flambeau with a very high specialty (60+ is easy) to an experienced Criamon or Bjornaer, to a Verditius with a minor focus with jewelry...
Anyway,
Ken
my misunderstanding!
I have to say, though, I would love to see all that played out. The reason Sympathy isn't capped by Warping Score when gained from die rolls is because rolling dice is fun, right? Capricious fortune making you gain and lose experience over time is kind of interesting, for the players and the storyguide. It's weighted so that you get more experience than you lose, but still that whole "I'm rolling the die now, what's gonna happen..." dynamic is quite enjoyable, I think.
Heh. Forgot to divide by 5. Whoops. 
Yes, but 12 of the lightning bolts done in such a way in one round?
Oh, with Verditius magi you can get the bonus applied to Craft, Magic Theory, and Philosophiae for some nice lab totals.
All these huge Sympathy scores make me think magi really should be subject to Faerie Calling when they botch using Sympathy Traits...
Hi,
I think that's how the designer expected it to work.
What Chris noticed, though, is that it is possible to generate many, many positive experience points with these die rolls, and (we both noticed) that warping can be made rare. The latter isn't a problem; some people hate botches (I really hate botch-driven games, though I admit that running them is much easier, and sometimes it becomes a lot of fun, especially for games with fast character creation) just as others love them. Even the power of adding sympathy to mastery isn't a problem; a lot of stuff has been sunk into that instead of into awesome Arts and Magic theory scores, which is where ultimate power really lies. But the easy xp farming is a big problem, sort of like the "minor" breakthrough of fast charged items from adapting learned magic to Hermetic, combined with experimentation (or worse, the breakthrough rules), or having an entity with a might score repeatedly take the quality that provides 50 extra xp.
Anyway,
Ken
Oh yes. I have noticed this. But doing this triggers the experimentation rules, whose botch rolls cannot be mitigated.
As for fast-casting so much, I have noticed people calling for changes to those rules even without sympathy. Using sympathy in this way does, however, cause botches to actually be possible.
One thing the game lacks is a notion that Arts and Abilities might have a cap. It might not be possible, for example, to have a Blacksmith Ability beyond, say, 15, because no one in all the worlds knows how to do this. Or Creo beyond 29. Advancing the state of the Art would then require a breakthrough. This would handle many issues, but is too complex to track.
Anyway,
Ken
This conversatio has shot right over my heah 
Fine by me.
=> MuVi general: Totally change a spell of less than half the of the Vim spell. The Vim spell affects the structure of the spell, not the things that the spell targets. A change in power of up to two magnitudes is a total change.
No contest here, you must use this, since you're going from lvl 05 to 15.
Also, the previous, easier, guideline ("changes less than level +1 magnitude of the Vim spell") specifically "may not change either the Technique or Form of the target spell"
So it is clear, from both fronts, that you must use this one.
You're also doing 2 things here: first, you're amping the magnitude, and then, you're changing the Te and Fo.
I'd say the base guideline to amp the power, +1 to change the technique, +1 to change the form.
And you need to cast it at Touch range (since it's your own spell).
This means: affect (lvl/2) for Per/Mom/Ind +1 touch, +1 change technique, +1 change form
=> Change a spell of level less than (Level - 3 magnitudes) / 2
=> lvl 05 * 2 = 10, +3 magnitudes = lvl 25.
You'd only need a lvl 15 to boost the level to 15, or to change the technique, or to change the form. Lvl 20 to do 2 of these.
This is not even that hard. With your focus, Int 2, die 05, Aura 3, this means that you need Mu 14 and Vi 13 to essentially change any momentary lvl 05 spell into any momentary lvl 15 spell (14+13+13+2+5+3 = 50/2 = 25).
As for Faerie Sympathy, 2 things:
And there is a different but similar interpretation. I could easily see the reading being that there are three options for the changes in the guideline, "both" being the third. So that's only one use of the guideline. That seems to be the prior interpretation. Yours is more that the "both" statement is extraneous and is meant to say you can apply the guideline again.
And while you're tougher with the level, you're more lenient with the flexibility since you seem to allow choice in the extra magnitudes.
This is why I'd asked Mark the question. There's no single right answer, just different interpretations. I just want to make sure we're in agreement before we get started. I think I prefer Fixer's choice here. It makes the spell levels a little higher at times, which isn't bad. Meanwhile it allows choice when raising the power level, which I actually find more in agreement with the examples than against them. The reason for this is that the ones that are out of the magus's control are extremely general, increasing the power of any applicable spell and thus in essentially many ways. If a spell were designed in a much more limited way I don't see that the magus shouldn't be able to have more choice, such as when the magus chooses to increase the Duration or Range.
Of course, you don't roll Craft for that. It's run more akin to a lab total. Not disagreeing with the 1 roll thought, just qualifying the reasoning.
That fixes a lot of it right there, and perhaps in the most simple method. I bet that would make everyone pretty happy.
As a quick summary, I'll just second Fixer's ideas. I think they'll work well overall, maintaining a lot of the desired outcomes without allowing lots of abuse.