OK, I'm sure this has come up, but humor me.
We'll start simple.

Magic vs Barrier
Power Bolt at force 6 vs Security Door, Armor 8, Structure 9.

I need to destroy the door to get through it.
Object Resistance = 4

So, I throw my 16 dice and get 6 hits. Minus OR4 means 2 net hits.
I do 8 points of damage, which beats the armor rating so I get to do damage. If I only had 1 net hit, my damage would be 7, not beating the Armor rating, so I would have done no damage.

The barrier rolls 8 dice, gets three hits and I do 5 damage, out of it's 9 structure. So there is no hole through it but it's damaged. I do the exact same thing next round, overcoming the structure of 9, and blow a 1 meter hole through the door, effectively destroying it.
Right? Am I missing anything?

Sounds about right.

OK, same situation, but I use Ignite instead.

It does the same 5 damage the first turn, and every turn I sustain it until the door is destroyed, right?
Or, does it not get a damage resistance test at all?

The door would resist damage with its Armor rating against Ignite.

That's what the 8 dice the door rolled were, right?

Objects do not get resistance rolls against direct combat spells. In your first example, the wall just takes 8 damage. SR4A 204, parenthetical at the end of the 2nd paragraph.

Ignite does nothing whatsoever until it becomes permanent. Ignite at force 6 has drain 3, so it does nothing for 5 turns, then on the 6th turn becomes permanent. At this point it is ordinary, nonmagical fire that does 6P on the 6th turn, 7P on the the 7th turn, 8P on the 8th turn, and so on until something puts it out or the structure is destroyed. It works like any other sort of mundane fire and is thus resisted with the barrier's Armor.

Pg 183 says they do, 204 says they don't. WTF?

Do you have a page reference for the ignite/permanent spell thing? I can't find it.

edit > Nevermind. Page 203.

Pg 183 says by default they do (and combat spells that aren't Direct work like that), then Direct spells are an exception to the general rule. It is indeed sloppy editing, though.

SR4A, p. 183, and p. 204 both state that Direct Combat Spells use the OR as a threshold, and Indirect Combat Spells resist with Armorx2, or Armor for Elemental effects. (Admittedly all of the Indirect spells that deal Physical damage are Elemental effects, but the case could be made to create a Physical damage version of Clout using the rules from Street Magic.)

My apologies for above, the post was discussing Combat spells and I forgot that Ignite was a Manipulation spell.

As I read it:
Powerbolt - slags the door directly, 8P no resist, just overcome the OR.
Flamethrower - No OR is used, Force 6 + 6 hits, resist 12P with Armor of the Barrier, possible secondary effects.
Ignite - Overcome the OR, Sustain until permanent, then as Umaro posted.

So for Powerbolt and Ignite the Armor doesn't come into play at all?

So, what if the Armor Rating goes up? Instead of a door, I'm trying to blast a cop car:
Chrysler-Nissan Patrol 1, Body 10, Armor 10.

Flamethrower wouldn't hurt at all because I need to beat the armor rating of 10.
Ignite would destroy it 2 turns after it became permanent.
Powerbolt would do a generic 6 points of damage to the body 10 car, mostly destroying it.
Right?

For Ignite, it follows the normal rules for Fire damage on SR4A p 164-165. It would be resisted with Armor.

Vehicle armor follows rules like Hardened armor--if modified DV does not exceed the modified Armor rating, it does no damage. From your example above, F6 + 6 hits, would be a DV of 12 against Armor 10/2 (because of AP). As 12 > 5, the Flamethrower would deal damage, and it would be soaked with Body + 1/2 Armor or 15 dice.

Right on. And the Power bolt would still just do it's 6 points.
force 6 + 6 hits - OR 6 = 6 boxes of damage, right?

Or am I going to need 7 hits to hurt it with an OR of 6?

Net hits add to the damage of Powerbolt (and Flamethrower) but not Ignite (net hits have no effect on Ignite).

what if the door was of non-flamable material?
Why do stones (OR1) burn easier than paper (OR2)?

Careful, if you keep sticking your fingers in the RAW holes, they might get stuck the next time there's a german stealth-errata published.

Unfortunately you do if the target is OR 6. Because someone probably screwed up, spells always need one net hit to succeed, despite the fact that threshold tests generally only need to meet the threshold.

You may want to update your rulebook. OR 6 only exists by GM Fiat. The highest listed OR is 5+ for vehicles etc.

There are redundancy-mods that increase OR, so values above 5 can be strictly by the books.

I forgot about those, where are they again?

WAR! pg. 175

...though I could've sworn there was something in addition to that one, in another book. Maybe I'm dreaming.

This only works on vehicles, not doors and such.

Yes. The talk was of a cop car, and you mentioned 'vehicles etc'

The door in the original post was quoted at OR 4.

OK, so pg 204 SR4a says:
"Note that nonliving objects resist damage from an Indirect Combat spell with their Armor rating x 2 (see Barriers, p. 166)."

Meaning that the Armor Rating of the car would be effectively 20, not 5, right? Or is there another reference somewhere that contradicts this as well?

That's for Barriers, which resist with Armor + Armor. Drones and Vehicles resist with Body + Armor.

AFAIK direct spells against objects don't use those hardened armour rules, because they are not resisted with armour. I.e. there is no comparison of whether the damage is converted to stun, and hence the entire hardened armour section cannot be used. [Edit:] Alright, you never said that. Duh.[/edit]

So a powerbolt that exceeds OR will always do Force+net hits damage, no further resistance.

For instance, last session I hit one of my runner's car with an F11 Shatter spell cast by a free spirit which hit the car with two net hits for 13P of damage, destroying it.

I don't mean the resist roll. I mean the amount of hardened armor I need to over-come with a flamethrower spell to damage a car with a body and armor of 10. Your post said 5, but what I read says 20. I like your answer better, but I need a reference.

I'd be more worried if a F11 spell *failed* to destroy a car.

Any Vehicle with BOD>10 would survive.

OK, just below the part about armor x2, it says elemental effects are resisted by armor /2.
So, our Chrysler-Nissan cop with body and armor of 10 would take at least a force 5 (or 10, as 10 x2 /2 = 10) fireball to damage it. Then it would resist that damage with 20 dice (or is it 15? Bod 10 + (armor 10 /2) = 15).
errr, I'm still kinda confused I think.

You're correct--direct spells just use OR. Indirect spells (like Flamethrower from the example) don't use OR and instead deal with the hardened armor rules.

Bearclaw--look at the rules for Destroying Barriers and Vehicle Armor (both conveniently on SR4A p. 167, with Vehicle Damage supplements on p. 170). The rules are slightly different--barriers don't have a Body rating, so they use Armor x2 for most things, or just Armor against Indirect Combat spells/explosives. Vehicles soak with Body + Armor, and AP modifies appropriately. If Modified DV (Force + Hits in this case) is greater than Modified Armor (Base/2 for Fire), then it works. There is no need to double armor.

Edit: So yes, your Chrysler-Nissan cop would roll 15 dice.

Dakka Dakka, how many cars have BOD>10? I count 3, if you include the armored limo and a 'heavy duty truck'. I guess 1-2 more if you include ones from the Security/Military section. The point was just that's a crazy-big spell.

Everything driven by cops.

Not the COP, which you specifically mentioned. That has a BOD=10, according to your numbers.

Yea, I guess the Citymaster is the only thing most runners would ever need to worry about with a bod over 10. But it's a lot over 10.
But really, if you're throwing a force 11 power bolt, you're probably throwing a lot of dice and getting a lot of successes, so maybe you can blow it up anyway.

On a related note:
So, I blast the Chrysler-Nissan cop twice for a total of 10 damage. The car is "destroyed". But that doesn't mean totally blown up in a big fireball that leaves no parts or pieces. it just means it's a dead car, right?
So, windows blown out, electronics fried, tires flat, and maybe a door or two blown off. But unless it crashed, no damage to the occupants, right?

I would think they would be at least a little warm from the, oh, i dont know, sudden explosions of flame? oh, and mabye a little short of breath due to lack of oxygen that the fires burned up.

That is why you use Powerbolt or Wreck Vehicle. No worries about Armor at that point (Just OR), and no fires to crisp the occupants that you likely want to interrogate before shooting in the face.

The "Classic Rigger Van" from the PACKS booklet has Body 16, Armor 20. Had a fun time when a Patrol car rammed it at full-speed.

Weird thing about ramming: even if the vehicle survives, the passengers are likely to be killed instantly (resisting the same damage, but with only half their impact armor? Crazy, man...I think I let them add their vehicle's armor in that case).

EDIT: Nevermind, I believe the book was referring to characters who were being rammed by vehicles, not characters inside of vehicles. That said, how do most people handle damage to people inside of a vehicle from a crash? Seems like the vehicle's armor would be useless in that situation (the damage is coming from you slamming up against the vehicle; it being harder than normal won't help matters at all).

I'm sorry, I meant to say "I blast the Chrysler-Nissan cop twice with a powerbolt for 10 damange...."
In that case, the car would be dead, but repairable, and the passengers would be mostly unharmed, right?

I would assume that if I did enough fire damage to destroy the car, the passengers would have to at least deal with the secondary effects of the car being on fire.

Fireball affects everything in it's radius of effect.
Powerbolt only affects the vehicle in question.
Questions as to HOW it affects it? No idea!

BIIIIIG BADABOOM.....

......multipass!

obviously....

In our session the destroyed car sort of fell apart, but everyone in it was unharmed. Including the free spirit's "husband" in the trunk. Unfortunately the runners then thought it wise to shell the thing. Well, not quite, but shoot some grenades...

Does Power-Bolt/Power-Ball simply disintegrate stuff?
Does it wreck shit up till it's scrap?
Nobody knows.
Fireballs are easy in this regard.
It burns/melts into slag/ash.
And this does not stop if you can't see it either.
If the fireball is strong enough, it simply explodes into anything.
For example:
Car has a trunk, has a case in it. No LOS to the Case.
Now you fireball the car with a fireball of force 6.
6m diameter fireball. throw some hits in to get the damage out that you need to actually do something to the vehicle.
You can be damn sure the case is going to get singed or molten or burned.

Now the Powerball:
Same car, same trunk, same case. No LOS to the Case.
Car suffers some kind of Damage. maybe it's completely annihilated, including the trunk . . .
The Case? No LOS to the case, remember? The Case . . falls down where the car/trunk was.
completely unharmed by the powerball. Not even dented/scratched.

The problem is that you need 7+ hits not net hits to deal 13+ boxes of damage to vehicles. That is about as high as it gets (without ridiculously powerful Power Foci and/or raised MAg through initiation). MAG 6 + Spellcasting 7 (with Aptitude) + 2 Specialization + 2 Mentor Spirit + Power Focus 4 = 21 dice. That dice pool will do 7+ hits half the time.

Force 11 however can be cast by every starting character with MAG 6.
I think the Blues mobile looks like it was hit by a power ball. Too bad I cannot find a clip.