The defender does the math in whichever order is most beneficial to him. This is not in the book but some 3.5 or PF dev said to do it that way. <--How I do it.
How I am thinking about doing it--->Just have them cancel out. It makes sense and reduces the math at the table.
The wording for Vulnerability is it inflicts an additional 50% points of damage against creatures of this type. Our group goes with the logical approach:
I cast a maximized fireball (10d6) at a white dragon. The fireball base damage is 60 points of damage. Because it inflicts 1.5x damage, it instead inflicts 90 points of damage. The White Dragon makes a saving throw, reducing the damage to 45 points of damage.
Now, from a physics stand point, it was able to dodge 50% of the original damage, and because it is vulnerable to the damage (it hurts it more) only the damage it saved against is multiplied. 30 * 1.5 = 45 points of damage. It had resistance 10 vs. fire so it's resistance soaks up the earlier damage (it didn't injure it).
Our groups last justification is this. Fire is a white dragon's poison. If you attack a dragon with DR 5/magic with a poisoned weapon and do 3 points of damage that doesn't bypass it's damage reduction. It doesn't need to make the fortitude save vs. poison because it didn't take any damage. The same thing goes with resistance.
The wording for Vulnerability is it inflicts an additional 50% points of damage against creatures of this type. Our group goes with the logical approach:
I cast a maximized fireball (10d6) at a white dragon. The fireball base damage is 60 points of damage. Because it inflicts 1.5x damage, it instead inflicts 90 points of damage. The White Dragon makes a saving throw, reducing the damage to 45 points of damage.
Now, from a physics stand point, it was able to dodge 50% of the original damage, and because it is vulnerable to the damage (it hurts it more) only the damage it saved against is multiplied. 30 * 1.5 = 45 points of damage. It had resistance 10 vs. fire so it's resistance soaks up the earlier damage (it didn't injure it).
Our groups last justification is this. Fire is a white dragon's poison. If you attack a dragon with DR 5/magic with a poisoned weapon and do 3 points of damage that doesn't bypass it's damage reduction. It doesn't need to make the fortitude save vs. poison because it didn't take any damage. The same thing goes with resistance.
Actually the damage taken is not determined until after the save. You do not take 60, jump out of the way and have it reduced to 30. The damage that it actually takes is multiplied, but resistance means the damage that actually hit it is decreased.
Actually the damage taken is not determined until after the save. You do not take 60, jump out of the way and have it reduced to 30. The damage that it actually takes is multiplied, but resistance means the damage that actually hit it is decreased.
That's true. For example, evasion, etc. such as a flaming sphere. I agree with this statement. As the damage they took as a result of the save is multiplied. However I would apply resistance first before inflicting the final damage. If any damage goes through, then that damage is multiplied. I always go with what is most beneficial, which is the normality.