Interaction of Vulnerability and Resistance

[the Jester]

Say a creature with the cold subtype has protection from fire cast on it. The PfF can absorb 120 hp of damage.

Our cold guy gets hit by a flaming breath weapon that does 80 hp of damage to him.

Does his PfF absorb the 80 points and go to 40 hp of protection before the damage is multiplied by the vulnerability? Or does the 80 hp become 120 hp and totally wipe out his PfF?

Also, what if, instead of PfF he has a magic item that gives him resistance to cold 30. Does he take 75 hp of damage [(80-30)x1.5] or 90 hp of damge [(80x1.5)-30]? In other words, what is our order of operations here?

 

[Zamtap]

The breath weapon does 80 damage and the PfF prevents this

then when the breath weapon hits again for 80 damage 40 is prevented by the PfF and the 40 damage left hits the vunrable creature and the creature takes 60 damage.

If he's got a ring of 30 cold resistance and gets hit by fire he takes the full damage.

If he's got a ring of fire resistance 30 and gets hit by fire he takes 50 which because he's vunrable to it becomes 75

Zamtap

 

[mvincent]

what is our order of operations here?

From the 3.5 FAQ:
"If the creature has both resistance and vulnerability to the
same kind of damage, apply the resistance (which reduces the
damage dealt by the effect) before applying the vulnerability
(which increases the damage taken by the creature)."
and
"As a general guideline, whenever the rules don’t stipulate
an order of operations for special effects (such as spells or
special abilities), you should apply them in the order that’s
most beneficial to the creature."