Fortification Reduction

[JackOfShadows2]

All skills/feats/enhancements that reduce enemy fortification:

10% reduction Rogue Opportunist,
25% reduction Precision,
10% reduction Improved Sunder,
8% reduction Improved Destruction,
15% reduction Grim Precision (Shadow Dancer)
10% Reduction Piercing Clarity (Grandmaster)


(Edit)Additional Sources:

You left out:
Armor-piercing 10%: Treason (base), Envenomed Blade, Doublecross Bow, Black Dragonscale
Armor-piercing 15%: Treason (upgraded)
Up to 50% from FvS shield procs.

I would expect everything except the two armor-piercing item effects to stack.

-25% from Touch of Despair (dark, dark, dark monk finisher).

So, my question would be which of these stack. I have found some threads on the discussing these and trying to mathematically prove if they do, but I'm just looking for player thoughts.

If you were running all of these things, would you really bypass 78% of the targets fortification?
Did I miss anything that could make that percentage higher?

[Tid12]

FVS aura for 50% more if it procs enough IIRC. Usually its 20-30% fort reduction. They should all stack meaning that you would get 100+% fory bypass if you really had all of this going on.

[xoowak]

You left out:
Armor-piercing 10%: Treason (base), Envenomed Blade, Doublecross Bow, Black Dragonscale
Armor-piercing 15%: Treason (upgraded)
Up to 50% from FvS shield procs.

I would expect everything except the two armor-piercing item effects to stack.

[ThePrisoner]

Black dragon scale armor - 10%.

I believe they all stack.

[Malison]

Favored Soul PrE, Angel of Vengeance, Shield of Condemnation has a chance to apply a 10% fort penalty, stacking up to 5 times.
Black Dragonscale Robe (or possibly other armors) bypasses another 10%.

vs specific types of enemies,
Silver Slinger, Bow of the Silver Flame, or Mournlode Chain Shirt / Docent -20% fort to undead.
Blasting Chime -20% fort to constructs.


I have no math for proving the way any of it stacks, but anecdotally it feels like it is linear.

[Coyopa]

I know from experience that Precision, Grim Precision, and Piercing Clarity all stack. I am currently running that combination on my monk and will be running that combination on my rogue, as well. The monk will eventually drop Grim Precision in favor of Sense Weakness. The rogue also has Opportunist, obviously. So, when I'm done with him, he'll bypass 60% fortification on everything that is not a construct - and 90% fortification on constructs (Wrack Construct 3).

[Dysmetria]

Can't mobs get over 100% fort just like we can?

[Shade]

Can't mobs get over 100% fort just like we can?

They could, yet it seems none of them do.

The devs originally stated that they would make undead and constructs 200% fort when they introduced ways to reduce or bypass fort, as you really shouldnt be able to crit or sneak attack those. But they either forgot or just decided against it, so they have 100%.

[Tid12]

They could, yet it seems none of them do.

The devs originally stated that they would make undead and constructs 200% fort when they introduced ways to reduce or bypass fort, as you really shouldnt be able to crit or sneak attack those. But they either forgot or just decided against it, so they have 100%.

I'm against 200% fort to undead and constructs. However, I would give them a good 150%. Not impossible like 200% but still hard if you wanna crit them.

[DarkForte]

They could, yet it seems none of them do.

The devs originally stated that they would make undead and constructs 200% fort when they introduced ways to reduce or bypass fort, as you really shouldnt be able to crit or sneak attack those. But they either forgot or just decided against it, so they have 100%.

Shhhh... do not remind them.

[bbqzor]

Can't mobs get over 100% fort just like we can?

Yes, in fact undead and construct mobs frequently do at higher levels. That is why something like opportunist or improved sunder on its own doesn't always result in sneak-attackable mobs.**

As mentioned above, everything seems to stack additively (except destruction/improved destruction, and armor piercing 10 and 15; I have not tested those combinations but I assume the higher ability would overwrite the lower). I've used the rest, and it all seems to be working okay as of U14.

Also, the Shadowdancer ability Dark Elusion can fully enable sneak attacks. While not fortification bypass proper, that tends to be the most frequent reason for making the attempt. At last check, the ability was correctly working as intended, and can certainly make things easier if simply landing sneaks is your goal.

** edit: apparently other posters claim otherwise, feel free to test for yourself. There are mobs which seemingly do clear 100% to me, as 35-45% bypass can still result in no sneak attacks (thats how I was setup last time I looked at it) but its nothing I want to invest time in re-verifying. Either way, GL.

[Nibor]

I have absolutely seen a difference in mobs where some can occasionally be sneak-attacked and some can't once I got some level of fort avoidance. The most obvious to me was Wisps vs Vine Stalkers - Wisps I'll occasionally see the sneak attack damage; Vine Stalkers, never.
I haven't played around much while in a maxed out Shadowdancer (on 20 remove "sneak attack immunity"); i'll turn that on and wander around some.

Edited to add: Yeah, I can sneak attack Water Elementals once the debuff hits - removes sneak attack immunity - but it's still a pretty low % of the time, so I believe some monsters have Fort & sneak attack immunity, which is why even debuffing their fort doesn't always mean you get a sneak attackable mob. It's not an indication of higher than 100% fort on mobs.

[JollySwagMan]

Has improved destruction been fixed to be -8%? (I may have missed that, last I knew of it was bugged to be the same as regular Destruction?)

[Adken]

Has improved destruction been fixed to be -8%? (I may have missed that, last I knew of it was bugged to be the same as regular Destruction?)

Yes. I don't remember in which update but i'm pretty sure they fixed it.

[sephiroth1084]

You also left out -25% from Touch of Despair (dark, dark, dark monk finisher).

Some monsters very clearly have sneak attack immunity in addition to their Fortification. Undead are the easiest to notice this on--no matter how much Fort you're ignoring, you won't be seeing SA damage.

[Nagantor]

There's not much need for the devs to push up fort on mobs, people don't use fort reducing much. Take a look on common raids, how often does someone use Improved Sunder and friends? Pretty rare, you can easily do a Shroud with 3 rogues and portals are never hit by wrack construct I even.

[Tid12]

There's not much need for the devs to push up fort on mobs, people don't use fort reducing much. Take a look on common raids, how often does someone use Improved Sunder and friends? Pretty rare, you can easily do a Shroud with 3 rogues and portals are never hit by wrack construct I even.

You play with the wrong people. If you are the leader, ask them if they got them. If they do, ask them to use them. There is always someone in a pug that uses them.

But anyway, for Shroud even 12 Paladins can kill the portals fast enough

[Coyopa]

You also left out -25% from Touch of Despair (dark, dark, dark monk finisher).

Some monsters very clearly have sneak attack immunity in addition to their Fortification. Undead are the easiest to notice this on--no matter how much Fort you're ignoring, you won't be seeing SA damage.

This is fascinating since my rogue gets sneak attack damage on undead from various places, including the Underdark, House of Death Undone and many more. Granted, he doesn't sneak attack them 100% of the time, but he currently only has 35% fortification bypass since he is in neither Shadowdancer nor Grandmaster of Flowers destinies.

[DDOGoz]

doesn't the regular destruction (up to -4% fort) stack w/ improved destruction?

[HAL]

They could, yet it seems none of them do.

The devs originally stated that they would make undead and constructs 200% fort when they introduced ways to reduce or bypass fort, as you really shouldnt be able to crit or sneak attack those. But they either forgot or just decided against it, so they have 100%.

Just curious why you shouldn't be able to crit or sneak attack undead and constructs?