I know that item attack speed max stack is 400% increase.
However if u have a item that increase 400% attack spell then i have another spell that increase 400% attack speed.
What will be the total amount increased? 400% or 800%?
As far as I know, a unit's attack cannot be increased beyond 400%* by any means. That even means that given enough agility, attack speed boosting items and spells will have no effect (a common problem in hero defense maps...)
*I've never tested whether that number is accurate; it's just what I've seen commonly accepted.
it is not 400% or 800%.
Lets say your hero has an attack speed of 2s.
After the 1st 400% increase, ur hero attack speed = 2s/4 = 0.5s.
2nd 400% increase = 0.5s/4 = 0.125s.
Ok, I just used a customized 'Item Attack Speed Bonus' ability, and turned it into a Unit Ability with the field "Data - Attack Speed Increase" set to 5.0 and a unit which had a cooldown of 2 seconds before, now has 0.4 seconds and 2.0 / 0.4 = 5.0 last time I checked, which means you can increase a unit's attackspeed beyind 400% in one go
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.