Multiplier and resistance, which one goes first?

[Liquidsabre]

Interesting to see that so many people multiply damage before subtracting resistances. Next session my players will encounter a frost giant cleric with protection from fire up and running. I can't see why a protection from energy fire spell would be less efficient for a cold type creature than a normal human. First the spell damage has to overcome the protective devices/spells, then the remaining damage will be increased by half.

~Marimmar

Hey, as long as it works both ways aye. So no complaining when you see a PC half-gold dragon (fire immunity/cold vulnerability) with a ring of cold resistance on.

 

[Altamont Ravenard]

Interesting to see that so many people multiply damage before subtracting resistances. Next session my players will encounter a frost giant cleric with protection from fire up and running. I can't see why a protection from energy fire spell would be less efficient for a cold type creature than a normal human. First the spell damage has to overcome the protective devices/spells, then the remaining damage will be increased by half.

~Marimmar

Here's how I justify it:

Resistance to energy absorbs a certain amount of damage per round.

A fireball (30 points of damage) strikes two friends (they both miss their saves). A is normal, B is vulnerable to fire. A receives 30 points of fire damage. B receives 45 points of fire damage.

Later, both A and B find a ring that gives them Fire resistance 10. Each round, their ring will absorb 10 points of damage.

Both friends are struck by another similar fireball (30 points of damage, they both miss their saves again).

A would have suffered 30 points of fire damage. His ring absorbs 10 points of damage. He suffers 20 points of fire damage.

(I don't know why I felt the need to go through all this example)

Without his ring, B should have suffered 45 points of fire damage. His ring absorbs 10. He is dealt 35 points of fire damage.

If you calculate it the other way ([30 - 10] X 1.5), you get 30 points of damage, 15 less that the normal damage he should have suffered. Hence, the ring has absorbed not 10, but 15 points of damage, but is supposed to absorb only 10.

AR

 

[jodyjohnson]

For what it's worth the order for DDM (miniatures) is:

Q. What if various effects are adding and subtracting to damage? In what order do you handle the math?

A. First apply all additions to the damage. Then apply all subtractions. Then apply any effects that multiply the damage (such as Vulnerable). If the effect specifies a minimum, and the result after all operations is less than the minimum amount, the damage is instead reduced to the stated minimum.

Miniature FAQ

 

[Lonely Tylenol]

I'm inclined to go with Stark. The resistance prevents the swarm from taking x amount of damage. However, any damage that makes it through the resistance gets increased. You increase the damage that they take, not the damage they could have taken. At least, that's the way it makes the most sense to me.

(edit)

If you were to Empower the spell, I'd say you would multiply by 1.5 for empower, subtract resistance, then multiply by 1.5 for vulnerability.

 

[RedShirtNo5]

I have a different approach to this issue.

I would extrapolate from the other stacking rules that, in general, the most recent effect in a stack trumps the others. So in this case, I would apply the "most recent" effect first. So a frost giant with a ring of fire resistance would subtract resistance before multiplying. An outsider with natural fire resistance but a template that gave fire vulnerability would multiply damage first.

-RedShirt

 

[FireLance]

Given the number of people who have chimed in with applying vulnerability before resistance. I felt I had to give my view. My preference is to apply resistance before vulnerability for one simple reason.

Suppose N (normal) and V (vulnerable) are warded by a protection from energy (fire) spell that will absorb 60 points of damage. Both are struck by the same three fireballs that do 20 points of damage each and both fail all saving throws.

If resistance is applied before vulnerability, the protection from energy spells absorb all the damage from the fireballs for both N and V, and both are remain unhurt.

If vulnerability is applied before resistance, N remains unhurt, but the first two fireballs discharge V's protection from energy spell and the third one deals 30 points of damage to him.

I suppose it could be argued that a protection from energy spell might have to "work harder" to protect a creature that is particularly vulnerable, but it seems to me that the effectiveness of protection should be independent of the item or creature protected. Look at it the other way. Say a third creature, I, who is immune to fire, is also warded by protection from energy (fire) and stands with N and V. If vulnerability (or invulnerability) is applied before resistance, then the protection from energy on him will still be active even after he was hit by the three fireballs.

 

[Al'Kelhar]

I've always played vulnerabilities as "this creature takes 50% more damage [from the relevant energy type] than a non-vulnerable creature in exactly the same circumstances". Thus, additional damage from vulnerability is always calculated last. So a frost giant wearing a minor ring of fire resistance struck by a 30 hp fireball suffers 30 hp fire damage if he fails his Reflex save ((30 - 10) x 1.5) or 7 hp fire damage if he succeeds (((30/2) - 10) x 1.5).

Cheers, Al'Kelhar

 

[Li Shenron]

Interesting to see that so many people multiply damage before subtracting resistances. Next session my players will encounter a frost giant cleric with protection from fire up and running. I can't see why a protection from energy fire spell would be less efficient for a cold type creature than a normal human. First the spell damage has to overcome the protective devices/spells, then the remaining damage will be increased by half.

~Marimmar

I think it doesn't necessarily have to work the same as the swarm case.

Since the rules don't officially help, it's up to the DMs, and as one of them I'd rather rule the two cases this way:

SWARM
1) count +50% damage from area spell: this is just in the nature of being a swarm, a collection of creatures; even before I consider which creatures make the swarm up, I imagine the "shape" of it being the cause of the increased damage effect (it's just an abstraction: they could have skip this rule, give swarms more Hp, and cut more other sorts of damage)
2) eventually halve the damage if the reflex save is successful, representing the flock of creatures partially dodging the flames, still as a whole
3) apply resistance, as each creature benefits from it after it has found itself among one of those affected by the blast

(besides rounding, 1 and 2 can be swapped obviously)

FROST GIANT
1) eventually halve the damage if the reflex save is successful, representing the giant dodging the flames
2) protection (completely or partially) blocks the fire from harming the giant's body
3) if some of the fire makes it through the protection, the frost giant's body gets more damage out of it because of its cold subtype

That's just a possibility, I don't see anything wrong in using others.