[Mäx]

If you (multi)cast 2 spells at force 6 each, it does not do 12S damage. It does 6S x2, each resisted separately by the target thereby giving them a better chance to take less damage.

There is no resistance test for direct combat spells, either the caster has net hits left after the targets spell resistance test and the spell does force+nethits damage(or just force if that optional rule is used, as using those net hits for damage isn't smart) or the caster doesn't have any net hits left in which case that spell does nothing.

[voydangel]

If you (multi)cast 2 spells at force 6 each, it does not do 12S damage. It does 6S x2, each resisted separately by the target thereby giving them a better chance to take less damage.

There is no resistance test for direct combat spells, either the caster has net hits left after the targets spell resistance test and the spell does force+nethits damage(or just force if that optional rule is used, as using those net hits for damage isn't smart) or the caster doesn't have any net hits left in which case that spell does nothing.

Ok, wrong wording. It should have read: "If you (multi)cast 2 spells at force 6 each, it does not do 12S damage. It does 6S x2, each opposed separately by the target thereby giving them a better chance to take no damage."

Which actually strengthens my argument, because that now means that by multicasting, you're increasing the odds of your spells doing nothing, rather than just reducing their damage potential.

But like I said before, I completely see how this would encourage overcasting, but not really multicasting. I just see low force spells negated too often to view them as a really big threat against anyone other than a grunt ganger. But then, my players and I know that spells hurt and don't skimp on the willpower or counterspelling, so we average more than 1 net hit to resist/oppose spells usually. 

[Chaemera]

But, if you're die pool before multicasting is 12 (fairly typical), and their die pool to resist is 3 (also typical), then multi-casting, your two die pools are 6 each against 3 each. On average, you'll hit with both (average 2 hits, vice average 1 hit). Yes, occasionally, you'll get bad rolls, or they'll get good rolls and you'll do none.

However, if you have the larger die pool, more rolling always benefits you in the long run. More often than not, rolling 6 against 3, you'll hit with both and do 12S damage. And even so, your odds of getting one of those two to be successful are high enough that you'll still get 6S most of the times you don't get 12S.

Part of you're wording (resisting), by the way, was correct. It's just that with the optional rule, since most casters won't choose to risk the extra drain, if you don't completely resist the spell, you take 6S per spell.

The caster's Spellcasting + Magic is resisted by the target's Body (for physical spells) or Willpower (for mana spells), plus Counterspelling (if available).

Emphasis mine.

[Nomad Zophiel]

What the rat with the chainsaw said. 
At 12 dice split to 6 vs 3 to resist, the target will generate two or more hits once out of every 15 times, more or less.

[Mäx]

What the rat with the chainsaw said. 
At 12 dice split to 6 vs 3 to resist, the target will generate two or more hits once out of every 15 times, more or less.

Thats why my combat mages have around 12 dice per spell if casting 2 spells.

[Nomad Zophiel]

I don't know, landing 14 out of 15 double casts at Force+1 is pretty impressive to me. Then again if the same fellow has to resist a three hit spell, he's going to do it about 1% of the time.

[voydangel]

What the rat with the chainsaw said. 
At 12 dice split to 6 vs 3 to resist, the target will generate two or more hits once out of every 15 times, more or less.

Thats why my combat mages have around 12 dice per spell if casting 2 spells.

Is that possible at character creation? Or are you referring to experienced characters?

[Chaemera]

What the rat with the chainsaw said. 
At 12 dice split to 6 vs 3 to resist, the target will generate two or more hits once out of every 15 times, more or less.

Thats why my combat mages have around 12 dice per spell if casting 2 spells.

Is that possible at character creation? Or are you referring to experienced characters?

Best I've gotten playing thought experiments with mage char-gen is as follows:

Magic 6, Spellcasting 6
Base pool: 12
Combat Spellcasting Focus +3
Specialization (Combat Spells) +2

So that's 17 dice un-split.

See here for various opinions on when to add foci or specialization dice to splitting dice pools. My opinion, based on the RAW remains that both would be added after splitting, so for two spells:
6+3+2 = 11 dice each.

If you prefer to use the FAQ approach, vice the RAW it instead becomes:
17/2= one spell DP 9, one spell DP 8.

Please keep in mind that I'm not skilled at Min-Maxing characters, so I wouldn't be surprised if there are people who can get the FAQ interpretation up to 12 DP each.

[Mäx]

What the rat with the chainsaw said. 
At 12 dice split to 6 vs 3 to resist, the target will generate two or more hits once out of every 15 times, more or less.

Thats why my combat mages have around 12 dice per spell if casting 2 spells.

Is that possible at character creation? Or are you referring to experienced characters?

Well the first post should say combat spells, not just spells.
And thats quite easily possible, 12 is even little low as both of the characters i'm prefferring to are mys-ads:
Magic 2 + spellcasting 4 = 6/2 = 3 + spec 2 + mentor 2 + combat spellcasting focus 5 = 12 dice per spell for 2 spells
and
Magic 4 + spellcasting 4 = 8/2 = 4 + spec 2 + mentor 2 + power focus 4 = 12 dice per spell for 2 spells

[Kot]

What about spells where Force isn't really an issue, like Armor, or Increase Reflexes? They both have DV of F/+x, but they rely on the number of Hits on the Spellcasting test. How do i calculate Drain here, because I'm a bit lost.

[Mäx]

What about spells where Force isn't really an issue, like Armor, or Increase Reflexes? They both have DV of F/+x, but they rely on the number of Hits on the Spellcasting test. How do i calculate Drain here, because I'm a bit lost.

Umm, just like every other spell, you divede the force by 2(round down) and add the modifier to that to get the drain value.
And remeber while those spells effect is measured by the amount of hits you get instead of force used the force still limits the amount of hits you can get.

[Kot]

Thanks. I suspected that much, but i couldn't find the rule anywhere in SR4A.

[Mäx]

Thanks. I suspected that much, but i couldn't find the rule anywhere in SR4A.

Pages 181 to 184 explain spellcasting and relevant rules pretty well

[Kot]

Yeah, but i couldn't find that specific rule (Force limiting Hits).

[Mäx]

Yeah, but i couldn't find that specific rule (Force limiting Hits).

Page 182, under tittle Force beginning of the third section