[Faust]

Trying to wrap my head around cold damage. Could use someone to use crayon to break it down for me.

Example: Wolf Shaman cast force 8 ice spear with 8 successes, mage rolls defense with 4 success.

1. Armor Jacket itself rolls AV(12)-Ap(4)? then mage then would make a resist test without or with out armor? Does that test still get an AP4?
2. How does this affect a quickened armor spell?
3. How does this affect things like dermal plating, Ballistic masks, forearm guards?

[jim1701]

Trying to wrap my head around cold damage. Could use someone to use crayon to break it down for me.

Example: Wolf Shaman cast force 8 ice spear with 8 successes, mage rolls defense with 4 success.

1. Armor Jacket itself rolls AV(12)-Ap(4)? then mage then would make a resist test without or with out armor? Does that test still get an AP4?
2. How does this affect a quickened armor spell?
3. How does this affect things like dermal plating, Ballistic masks, forearm guards?

Indirect combat spells have an AP equal to their force period.  So the AP in this case is -8.  As for the elemental cold damage side effect the armor item in question makes a simple test which as I understand it means you roll the armor value of the item as a dice pool.  If you get no hits the item breaks and will need repair, if you glitch or critical glitch the item is destroyed.  With one or more hits the item is fine. 

Neither stacked armor nor cyberware is really addressed so AFAIK it is up to your GM to decide.  If you roll for each item separately it does make low value items like helmets a lot more susceptible to breaking.  That might not be such a bad thing since it might actually make cold damage worth using.  For cyberware such as dermal plating it is again not really addressed but I wouldn't do that.  There really isn't any rules for physically damaging cyberware nor repairing it.  Personally that isn't a can of worms I'd open.  Also armor from the armor spell isn't an actual physical item so I would not allow cold damage to actually "break" it either. 

[kilroy]

Here's an example with some characters from my game:

Doc, a Hermetic Mage, is on his way to the Stuffer Shack for some Queso Soyritos, a can of Fizzy Goop, and a box of gauze to patch up his team's Face. On his way there, he is accosted by FailBoy, a ganger who has picked on the wrong random passer-by. One thing leads to another, and FailBoy pulls a gun. Doc takes exception to that, and slams him with an Ice Spear.

Doc casts a Force 7 Ice Spear, and gets 5 hits on casting. (And rolls his Logic + WIllpower to successfully resist (Force-3) 4S Drain)
FailBoy must be a little hungover tonight, and only rolls 2 hits defending against the Ice Spear.
Now FailBoy must resist 10P (Force 7 + 3 net hits) Cold damage, using 9 dice (Body 4 + [12 Armor Jacket - 7 AP]). He gets 3 hits, and takes 7 boxes of damage. Since the damage is higher than his modified armor of 5, it is Physical (ouch!). He's also knocked down, since the 7 damage he took is higher than his Physical Limit of 6.
Now, he needs to need to roll dice for his Armor jacket equal to it's armor value of 12. If he gets no hits, the object breaks and needs to be repaired. If he Glitches, it breaks and can't be repaired. If he Critically Glitches, it breaks in a way that is dangerous.
FailBoy is now on his back, with 7/10 boxes of Physical damage, and it's possible (but unlikely) that his Armor Jacket is no longer providing him with armor. He begins to reevaluate his life choices.

As for armor stack items and 'ware, I mostly agree with jim1701. I wouldn't make them do it for cyberware, and depending on the situation I might do it with helmets, forearm guards, etc. The rules don't directly address either situation, however, so it's going to boil down to what the GM feels like doing.

[Reaver]

Again, I side with the above 2.

SR doesn't really do a 'hit location' combat system.... its assumed most rounds land on center mass. (See RnG for called shots). The only time I would apply cold damage to stacked armor is with a called shot....so shooting for the head may result in the helmet taking the cold damage. (But, in the interest of fairness, that means his jacket doesn't have to resist.)

As for cyberware. Most of that is inside the human body. If the cold from the spell could 'break' that inside of you, you have bigger problems, as flesh doesn't handle thermal shock nearly as well as silicon. Flesh either turns black and dies (frostbite), or bubbles, blisters, and melts (burns) at temperatures that cause circuitry to fail.

Ie: cyberware gets a pass.