Can someone explain to me the difference between major and minor magical focus? I know it's probably written clearly, but I am not getting it.
Well, major focuses have a greater scope, for once.
Moreso, when you cast a spell which have a requisite, the lowest score (that may be doubled) may be the requisite, and it is not limited by the standard art if inferior.
Say, you cast a MuCo(An) spell with Mu 15, Co 11 and An 10. Your casting total is 15 + 2*10.
With a minor magical focus, the requisite may be doubled, but it is then limited by the standard art.
If you cast the same spell, your casting total is not 15 + 210, but 15+11, as 11 is lower than 210.
OHHHHH Thanks!
My pleasure 
I believe that the errata has made it so that the only difference between major and minor focuses is the scope.
I confirm, the corrected minor focus virtue is like a major one in regard of the calculation of the arts. Scope is the only difference.
What do you mean by "scope"?
A minor focus only applies to a narrow category (e.g. wind), while a major focus is broad (e.g. weather). Check the tables on pages 45 and 46 of the core book for more examples
Sorry me, I never checked the errata. Too lazy 
I like it better that way, though, so I should have
Being large and easily confused by words, let me ask this august body this.
Consider a Magus with Muto 20, Corpus 15, and Animal 10. He is casting a MuCo(An).
Without an appropriate focus:
Mu 20 + Co 15 (treated like 10 because of An 10) = 30.
With a focus his total is:
A: Mu 20 + Co 15 (gets to use full Co value, because Animal is doubled) = 35
or
B: Mu 20 + Animal 20 (lowest art added twice) = 40
The way I normally think about requisites makes me think "A" but the rules seem to say "B". Have I been wrong?
Before the errata, it was A for a minor focus, B for major.
Now, it seems it's B for everyone. Enjoy
The lowest art after handling requisites is doubled, so it is B regardless of whether it is a minor or major focus.
A question of scope:
If I'm reading the rules correctly, Belladonna chose the crow family of birds for her MINOR magical focus. This allows for the bonus to apply to the combination of ANY technique combined with Animál, as long as it has to do with crows.
I (her storyguide) didn't think it needed to be any narrower (like limiting it to one tech/form combo), per my reading of the rules.
thoughts?
Minor Magical Focus (p 46)
"Your magic is particularly attuned to some narrow field, such as such as self-transformation, birds of prey, or healing...
I would suggest that "crows" is, in fact, much narrower than the example "birds of prey", and rather than consider narrowing it even further, she should be given a broader range of effect, such as "carrion birds", or "crows and (one other very specific & appropriate animal or category)". (Keeping this thematically appropriate to Odin is another matter. Spears, maybe? Gallows?... Eyepatches?...*)
Note also that it goes beyond merely the Art of Animal- I can see Imagonem being useful (crow sounds, illusion of crows, etc), and Mentem (fear of crows, dreams of crows, memories of crows, etc), and conceivably Aurum (only if the spell directly and appropriately affected mundane crows), and possibly others.
A spell effect that changed on oncoming stormcloud into the shape of a huge crow (Imagonem? Aurum?), for instance, I'd allow, if only for the creative addition to the story.
(*Edit- the more I think about it, the more I'd consider letting her focus encompass "gallows" as well. It's not like it's out of the SG's control when she can use it, it ties in nicely with the overly-narrow "crows" (unlike most other "animal/object" combos!), and with the Odin theme. But that's just me.)
Yeah, as Cuchulain said.. I wouldn't limit it to one form, as long as it's sufficiently narrow.. and indeed, crows is fairly narrow ^^
Of course, that depends on it not being abused too much.. hehe
But the rules go on to say:
"In general, the field should be slightly narrower than a single Technique and Form combination, although it may include restricted areas of several such combinations."
Therefore, I think that the crow family (including ravens, rooks, jackdaws, jays, magpies, treepies and nutcrackers) seems appropriate. My concern about whether it should be even MORE narrow is due to the specificity of "single T & F combo."
I think you have a very good point about using other forms however.
I don't know if I abuse it, but I use it alot.
Oh, that's briiliant! C'mon, Firth, You've got to let me have gallows! Hehe 
I agree with you there.
I would require you to take it as a Major focus if you wanted to have things that are merely thematically associated with crows.
Yeah, That's what I think he will say. But a theme like "all things linked to Odin" is really cool, and I would have probably done that if I had thought of it in the beginning.
"all things linked to Odin."
Belladonna, your character has heard of the mythical enemies of the Order of Hermes, the Order of Odin.
Perhaps these rune masters know of some mysterious magic that could widen your minor magical focus to include all things related to their godking.
Of course, if you mess around with these folk, you may anger the Order, or might just get yourself killed....
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