Weapon skill and armor ignore tactics

[Ithiel]

Hey guys,
Could someone explain to me how weapon skill and armor ignore tactics interact?
For example, a WL has 30% armor pen from WS and equips hack and slash (50% armor ignore on aoe abilities) – what is the resulting armor penetration/ignore? Do they add up to 80% or they cap at 50%?
In the case they cap at 50%, if that same WL invests in WS to achieve a 60% armor penetration – does this make hack and slash obsolete for him?
Thanks a lot for your help!

[oaliaen]

Armor pen cap at 75%. Thats why some classes are 'better' than others, like Mara having 50% armor pen and WL hack and Slash tactic and Choppa have to invest everything in WS to make some damage.

[Ysaran]

They should stack addictively, so in your example would be 30%+50%=80%. Also armor pen is capped at 75% but you should try to get a bit more of it because many gears have +x% reduced armor pen stat

[Fenris78]

I'm not sure armor pen is capped at 75% ; what is capped is WS to 1050 wich effectively equals to 75% armor pen.

Also I'm not sure bonuses are either stacked Additively (I read they are multiplicative in another thread), nor are equal armor pen from WS and effects that "ignore % of armor".

For example, tactics like "ignore 50% armor" may apply after armor pen from gear and WS, resulting in lower output value on tactics, or the opposite apply before, resulting in lower output value from WS/Armor pen.

I'll like to see a dev's post explaining all calculations because its still really confusing ATM...

[Ysaran]

I'm not sure armor pen is capped at 75% ; what is capped is WS to 1050 wich effectively equals to 75% armor pen.

Also I'm not sure bonuses are either stacked Additively (I read they are multiplicative in another thread), nor are equal armor pen from WS and effects that "ignore % of armor".

For example, tactics like "ignore 50% armor" may apply after armor pen from gear and WS, resulting in lower output value on tactics, or the opposite apply before, resulting in lower output value from WS/Armor pen.

I'll like to see a dev's post explaining all calculations because its still really confusing ATM...

As far as I know invader proc for choppa's (+20% armor pen while berserk) stack additively, i tested it. Also Mara tactic stack additively, or at least that what some expert mara i play with told me