O8S Damage down - does anyone know how much the debuff is?

[Mnemosis]

Without looking into it, I always thought all damage downs inflicted the same penalty. I remember the damage down in A3S would be like a 90% debuff or something, and assumed they were all like that.

[KarstenS]

Without looking into it, I always thought all damage downs inflicted the same penalty. I remember the damage down in A3S would be like a 90% debuff or something, and assumed they were all like that.

In O8S the damage down is stackable.

I did a quick look into a video I still have. With just some single numbers I would say 1 stack is 20% or 25% damage down. So with the maximum of 3 Stacks it would end with 60% or 75%.