Extra energy damage vs. energy resistance

[Quasqueton]

Fire Subtype: A creature with the fire subtype has immunity to fire. It has vulnerability to cold, which means it takes half again as much (+50%) damage as normal from cold, regardless of whether a saving throw is allowed, or if the save is a success or failure.

Resist Energy: This abjuration grants a creature limited protection from damage of whichever one of five energy types you select: acid, cold, electricity, fire, or sonic. The subject gains energy resistance 10 against the energy type chosen, meaning that each time the creature is subjected to such damage (whether from a natural or magical source), that damage is reduced by 10 points before being applied to the creature’s hit points.

Say a fire giant has resist energy (cold) in affect. When hit by a cold damage spell, in what order do the effects work? If the cold damaging spell itself does 20 damage, does the giant take (20 x1.5 -10) 20 damage? Or (20 -10 x1.5) 15 damage?

Quasqueton

 

[diaglo]

i vote for #1.

 

[Crothian]

concur

 

[MichaelH]

You add the +50% first because that is the actual damage taken. Then you apply the resistance.

 

[Quasqueton]

That's how I figured it at first. But then I got to thinking: doesn't the resistance kind of "stand between" the creature and the damage. So the resistance takes off its portion, then the remainder hits the creature. The creature's vulnerability then kicks in and increases the hurt.

Is the resistance like a shield before the effect, or like a sponge after the effect?

Quasqueton

 

[Pyrex]

I've always preferred the "shield" viewpoint.

1: Save for half?
2: Apply reduction from 'Resist Cold'
3: Multiply remaining damage x1.5 & apply to HP.

 

[Otterscrubber]

We have always played that if there is a modifier to the amount of damage, such as increasing in the example above or decreasing (as in you made your saving throw vs. lightning bolt), that gets applied first before any damage reduction or resistances. I cant quote anywhere in the PHB or DMG to back this up off hand though.

 

[Crothian]

sponge after. THink along the lines of acritical hit against a creature with DR. Calculate all the damge first, then apply the defense to it.

 

[MichaelH]

IMO, it is like a sponge after the effect. For example, a creature with fire resistance 10 takes 36 points of fire damage from a fireball spell. If he makes his saving throw he takes 18 - 10 = 8 points of fire damage. If he fails his saving throw, he takes 36 - 10 = 26 points of fire damage.

 

[Ridley's Cohort]

sponge after. THink along the lines of acritical hit against a creature with DR. Calculate all the damge first, then apply the defense to it.

A strong argument. DR and energy resistance should be consistent.