ability percentage stacks?

[Gemina]

Eh.. that's not an argument. Tooltips can be wrong, and have been in the past, besides they provide no information about how they combine.
It's a generally accepted theory that it's multiplicative, and I have tested it a bit a few months ago. I can't find a recent source with test data however, so I have no valid proof ready. I might get back to this later, to show some data :P

I wasn't arguing. I was just backing you up But I was under a previous impression that tooltips are accurate to what they say. I never tested it myself to see if it is doing what it says it does. Though, I guess technically if we went strictly off the tooltip, I think the formula would be ((.05 + .4) / 100%) = 45%

I also assume that healing buff stacks are multiplicative because HP restoration isn't a set number, but we would have to see the actual coding that goes into HP restoration along with the RNG constants that influence them. At least I think anyway. I'm not the best at this kind of thing.

[Canadane]

"Increases your critical hit rate by 100%" would mean "you will always get a critical hit" though. That's not confusing wording. "Doubling" is implicitly multiplicative, whereas "increases" is implicitly additive.

Well would increase the stat, not the rate. if your 'crit hit rate' stat is 1208 and you increase it by 100%, your crit stat is now 2416. Having 2416 crit may not actually be a guaranteed crit hit on every attack in the way the stat is calculated.

[JackFross]

Well would increase the stat, not the rate.

I would agree with you if any of those skills affected your stat, but they do not. Berserk, on the other hand, which increases your Attack Power by 50%, shows it in your character scan. Protect, which boosts your Defense by 15%, shows it in your character scan. Foresight, which boosts your Defense by 20%, shows it in your character scan.

Internal release, which boosts your critical hit rate by 30% (10% cross-class) does not show it in your character scan. Therefore it's not increasing the stat, so it must be increasing the actual hard-and-fast rate.


To add on to this discussion, we actually have a situation where we can examine multiplicity v additivity with respect to certain stats.

My Paladin, at i224 has 2201 defense.
When I use Foresight, my defense goes up to 2641. (2641/2201 = 1.20 = +20%, as the tooltip states.)
Casting Protect with Foresight active jumps me to 3037. (3037/2201 = 1.38 = +38%... which is more than +35%.)
After Foresight falls off, my defense sits at 2531. (2531/2201 = 1.15 = +15%)

1.20 x 1.15 = 1.38 - precisely the percentage difference we saw with both buffs active.
Further:
3037/2641 = 1.15 = +15% from the Foresight-buffed +20%.
3037/2531 = 1.20 = +20% from the Protect-buffed +15%.

I won't say that we can safely extrapolate this data and apply it to damage dealt and health healed, but we can absolutely extrapolate this data to damage dealt and health healed.

[subteraneanbird]

Most combat skills are multiplicative (As has been previously stated, combat buffs which affect rates of actions are additive ie Internal Release, Bulwark). This has been thoroughly tested to hell and back.

Crafting and gathering are additive.

Those two being additive does not change combat being multiplicative.

What this means in practice is it's worthwhile to stack output buffs (both offensive ones and healer ones) and unadvised to stack defensive buffs unless necessary.