Spontaneous Magic Modifiers

I've been trying to figure out what this means for a while, it seems to have no actual impact. What circumstance can modify a casting total, besides the die roll and the casting score?

We know that a Casting score is Technique + Form + Stamina + Aura +[other optional modifiers from virtues/flaws]. We know Casting Total is Casting Score + Die Roll, but I don't see any other modifiers, nor do I recall using any or seeing any used ever. Were it not defined as such, the fatiguing spontaneous magic casting total die roll could be considered a modifier that affects the casting total, but it is explicitly stated that the die is divided by 2, so that one's out.

Edit: Fixed munged quote.

HoH:S, in the Ex Miscallenae chapter, has the rustic magi being able to boost the casting total of their magic with foci.

Given as they have to divide by five when sponting, the fact it doesn't get divided is very significant.

E. g. an ArM5 p.53 Deleterious Circumstance. The former bonus from p.98 Talisman Attunements to casting totals has been errataed, and now applies to casting scores.

Cheers

Well, Deleterious Circumstances explicitly states to do so; halve the casting total, so yeah. But I was looking for something more along the lines of what kingreaper mentioned...

How about the attuned bonii from talismans?

As One Shot said, that has been changed in errata to affect the casting score, not the casting total.

Spell Improvisation from HoH:MC 87 also add to the Casting Total but do not stack with any other bonus.

related question :
the penalty for fast cast, no gesture, no word are taken after or before dividing ?

By RAW they are defined as being adjustments to the casting score, so before dividing.

I want to revisit this and extend the discussion, since it appears that there are few modifiers to the casting total, except as outlined above.

I'd like to ask anyone who used talismans as a modification to the casting total for spontaneous spells (not dividing) as the first and second editions have it published. I have a pretty good idea of what this allows, but I'd like to get the impressions of the Ars community generally.

Charms also add to casting totals.

A Merinita with folk magic who gets the foci virtue can readily put together lvl 15 sponts without fatigue or botch dice. Casting ceremonially with a correspondence adds to the fun (though these bonuses go to score).

Penetration is Casting Total + Penetration Bonus - Spell Level, so the penetration bonus is not halved for a spont spell. Casting props are unclear, though a better question might be can casting props be used for ritual spells?

Penetration is Casting Total + Penetration Bonus - Spell Level, so the penetration bonus is not halved for a spont spell. Casting props are unclear, though a better question might be can casting props be used for ritual spells?

Yes, why shouldn't they be. Moreover, the Jerbiton section offers special additional props for ceremonial magic.

But, it doesn't add to the casting total, it adds to the penetration total which is CT-Spell Level. So, yes, I agree it isn't halved, but it doesn't add to CT, either. I'm not usually trying to figure out how to penetrate on Spontaneous effects, anyway. Expending fatigue and botching spells in battle is bad.