Does Vulnerable overwrite or stack with Resistance?

[Caliber]

Simple question, illustrated using a scenario: If I'm fighting a creature with Resist Fire 10, and then whack him with a power that gives Vulnerability Fire 5, how does this creature now interact with Fire damage?

Does it take 10 less Fire damage (Vulnerability does nothing because it is already Resistant)?

Does it take 5 less Fire damage (Vulnerability effectively takes off 5 'points' of Resistance)?

Does it take 5 more Fire damage (Vulnerability overwrites Resistance)?

Thanks!

 

[HeirToPendragon]

WotC answered this recently on their site.

They stack. The creature would now have Resist 5 fire. If you're fighting a minion and whack him for 8 fire damage, he'll live. But the next time you whack him for 8 fire he'll die (assuming he didn't save or anything).

If you have a creature with Immune Poison and give it Vuln 5 poison it's still immune (think *0)

 

[BendBars/LiftGates]

Right. There's no order to when you apply these traits. They stack simultaneously and if the end result is a positive amount of damage the creature takes that.