Poison stacking

With a slow poison, are attack rate and movement factors additive or exponential? Like if you have a stacking .25 movement penalty, will speed be decreased to 75%-55%-40%-30%-25% or 75%-50%-25%-0%-0%?

I don't know... people always confuse me when they talk about stacking %s in wc3

I dont think poisin stacks, just look at all those td maps, since poisin dosent stack theres the adding cold to attacks to try to make it easier for them.

As concisely as possible: Additive, with minimum/maximum value.

Practically all "same-stacking" in WC3 is additive, but there are minimum above 0 values (for things like movement speed) and also a new feature in TFT that sets stacking for move/attack speed abilities on/off. I'm not sure exactly how it works, but suspect it does something like just taking the largest reduction and using that (ie if slow and slow poison are both affecting a unit, it moves at slows -60% speed).

AFAIK everything is additive until you start stacking entirely different buffs, like obviously the net effect of attack-damage buff/debuffs is multiplicative with attack-speed buffs/debuffs when it comes to determining the units damage over time.

Slow poison does not stack.

BUT...

This DOES stack (and practically brings monsters to a stop...):
Slow poison + Cold arrows + Frost attack + Slow

Which is why in a TD map its always good to put the Slow Poison, Frost Attack and Cold arrow towers next to eachother..

No cold effects stack to my knowledge...

Frost arrows (Sorry, I said cold arrows in my other post) and Cold attack are DIFFERENT attacks and Diffent effects, (this is easily noticed when a unit is hit with both of these attacks, it will show a "Buff" icon for both of them in the "Status" box.)

Frost arrows is a spell, cold arrows is a passive ability...

God i love testing stuff. Even when I prove my earlier statements wrong.

All slowing effects stack additive, however, by default, movement speed will not go below 150 (I believe this was increased from TFT, because in RoC I remember Chill+Poison in TD's pratically froze enemies).

In most cases, slow, slow poison or frozen arrows higher than lvl1 is enough to bring a units movespeed down to 150, unless they are buffed by unholy,endurance auras or bloodlust. But anyway, that means in most cases, only one of those is required to cause a unit to move at minimum speed.

You can change the minimum speed in Gameplay Constants, to whatever you want.