I wanted to ask about magical focus but I do not consider it big enough for a thread so I hope All virtue questions would fall under this thread.

So, when you make a Diedne magus who has virtues Diedne magic and minor magical focus, what happends?

a) his spontanious magic can double both arts when within his magical focus.

b) he gets no benefits of his magical focus when using spontanious magic.
- quite bad if he is unstructured caster that fits his concept.

Basic rule in character creation is that all merits should have benefits and min-maxing is forbidden so how to solve this rules dilemma neatly?

I think first solution would be to re-read virtue 7 times.

Then you find Diedne magic benefits.

a) cast spontanious magic at 1/2 level without fatique

of

b) cast at 1/2 level with fatique, but double lower art.

- so within magical focus, magus can cast spontanious magic without fatique + having his lower art doubled.

Did you reply to yourself?

The question I beleive is what happens if the magus does expend fatigue to cast a spell that also happens to fall under his magical focus. Does the lower art score get doubled twice?

well mages have changed weaker since the 4th edition, so I quess it's okay to add 100% to the casting total twice, increasing it by 200%.

and yes, I tend to answer my own posts when I find answers, but as an individual, am unable to see the whole picture. Multiple eyes see multiple issues.

Good question.
I tend to forbid all "combo" in virtue choosing. I mean that taking one specific should not make another virtue better.
The problem I see is not that you can't give two times the +50% bonus for the lesser art.
The problem, in my opinion, is that those virtues was designed to be balanced in such a way that it could not give TOO MUCH. It is no coincidence that the bonus go to the lesser art: it discourage the mage to study just one art and get big bonus out of it.

Giving 2 X (+50%) is in my opinion too much, as it will give the mage too much power comparative to others his age, even when comparing with their specialties.
( ex: Pe:20 Co:15, normally would get 50 just for arts; but with 2X, 65 ! doing 7th spontaneous spells, when IMHO 30 should be top maximum for this mage in his speciality, even 25 or 20)

My solution would be:
Don't allow to take the two merits, or
invent a new bonus for the Minor focus, like having all spells in his focus masterised (like flawless magic, but only in focus), or other bonus.

Iudicium

I think that if magic focus has many occasions it's beneficial, it's worth it's price even if Diedne magic overlaps it's usefulness often.

Diedne magic bothers me... I tried to make a magus that cannot cast formulaic magic, only spontanious magic but could not find any good art combination, this magus seemed really impotent. Formulaic magic is just so much more powerful.

Perhaps when she has gotten her arts up a lot..?

Spontaneous is always (and meant to be) less powerful than formulaic. It's neat with its flexibility, but severely lacking in power. If you can only do spontaneuous magic, that means no Rituals, as well as no truly high level spells (which are Rituals), plus no access to advanced ranges and such.

To make your Magus powerful in spontaneous I suggest a few things. First take Diedne Magic, then take a Minor magical focus. From there take Skilled Parens and Educated (though your spells and extra spells will generally be wasted). This will give you more XP to spend. Also take Virtues that increase study totals and Affinities, including maybe Affinities for Penetration (you'll need all the help you can get), and taking Special Circumstances (Spontaneous spells). Make sure your Arcane skills are good, you're not going to pull off high spells, so you want to make sure that they at least have a chance to work. When assigning Arts make sure you have a score in every one, otherwise you won't get much from your Virtues (doubling 0 is still 0). A major Flaw of No Formulaic Magic does not exist, with your GM's approval perhaps you could take it (though it's not very balanced, not being able to cast Formulaic spells is a heck of a flaw). As a GM, if one of my players wanted to take such a Flaw, I'd probably allow them to take 2 Major Hermetic Virtues instead of one as compensation (Diedne and Mythic Blood, or Major Focus comes to mind). If you took Poor Formulaic Magic (Minor) and Unstructured Caster (Major), that simulates well enough I suppose that you don't use Formulaic magic though.

Spend a lot of time in the lab raising your Arts, as well as collecting Arcane Connections. Make a Talisman, especially of a Staff or Wand, and attune it with all the fixings, and choose its material well. You need to squeeze every bonus you can out of it. If a Flaw of No Formulaic Magic were allowed, it should probably have a balancing factor, since you lose those starting 120 levels of spells. Perhaps more XP for Arts for example. Understand that for quite a while this Magus will be under powered compared to others. And even when you start getting your Arts into the 20s, the main thing you'll accomplish is impressive Spontaneous spells, but will still likely be outperformed by others casting Formulaic. However, your Arts will likely be higher, because you don't need to spend time inventing/learning spells, and far more flexible. You should also make magic items to compensate for no spells, as those flaws don't apply to enchanting. A Verditius with this combo could be useful, though might not make as much sense.

Sorry if this sounds too min-maxing, but I myself find the concept of a Spontaneous expert appealing. To make it viable requires some min-maxing IMO.

Rigid magic seems quite appropiate with Diedne magic, though caster stills uses formulaic magic.

muto & corpus 9 & rego & mentem 10 gives a good range of spontanious spells. With speciality of (minor focus) changing memories, druid has useful enough range of spells at start.

I think that if you specialize into spontanious magic, you must avoid spells that need penetration. (like muto mentem...) Illusionist seems like a good idea.

Thank you for you tips.

I remember it must be unstructured caster that made character unable to cast formulaic magic, they turn into rituals.