Any rulebook for AOE stacking debuffs? with Proof?

[GhostintheShell]

Anyone know if the following DEBUFF stack on the physical and magic defense?

1. ISS's Assault Crash - AOE debuff -40% p./m.atk -40% p./m. def

2. ISS's Chaos Symphony - AOE debuff -40% p./m.atk -40% p./m. def plus -50% skill crit rate

3. Feoh's Mass Ruin - AOE debuff decrease skill crit rate -15% plus -30% p./m. def

Is there a way to prove this either way?
If the debuff landed does not remove previous debuff in the player buff/debuff informational bar, does that mean it DOES stack?  Or it only take the HIGHEST or LAST (given equal) debuff only?

[Quenia]

Hello,

Afaik max -p/m def was capped at 50%, not sure if it has been changed along the way (i doubt it though).

Ez way to test is to try dbf yourself or any toon you can check the stats to see for yourself.

[LordDragnil]

What about ignore defence over debuffs? 

[Daikon]

8 hours ago, Quenia said:

Afaik max -p/m def was capped at 50%, not sure if it has been changed along the way (i doubt it though)

That's for mobs only.

[Quenia]

15 minutes ago, Daikon said:

That's for mobs only.

It's a bit more complicated but it's true for pvp also.

You may read this :

https://eu.4gameforum.com/threads/11857/

Haven't checked it myself recently...

Edited April 8, 2020 by Quenia

[GhostintheShell]

9 hours ago, Quenia said:

It's a bit more complicated but it's true for pvp also.

You may read this :

https://eu.4gameforum.com/threads/11857/

Haven't checked it myself recently...

Thanks for that link, very helpful!