Not realy that odd. Multiplicatively is the most normal way to stack %, and it is often the best way.

I dont know if there is a limit to the amount of slow, but the calculations look good.

There is NO 30% max slow "cap" why would there be? That would defeat the purpose for stacking slow effects.

There IS however a favor item that puts a cap on your max amount of slowness to 25%(also gives 5% extra run speed).

Why would there be such a favor item if there was already a 30% "cap" anyway? kinda defeats the purpose of this favor item. lol.

thankyou for clarification, i read somewhere in these forums that there was a slow cap.

also WTB nerf now

Ok i give you that, but would just be stupid with a system that could reduce move speed to 0  , that is probably why they did not use it on negative move speed. 

I'm pretty sure surge of faith only boosts allies movement and attack speed. That would explain why it didn't show up in your debuff list.

Are you sure you didn't have boots of speed because because that would make it

5.4+10%(0.54) = 5.94

5.94 - 56% {30+10+16} (3.3264) = 2.6136

Always thought temporary debuffs should be more powerful than constant buffs so in a way it makes sense to me.

There is a 2/3 Slow cap for stacking!

The problem you are facing got nothing to do with stacking, individual slows can still lower your speed more then 33% if they alone provide the effect.

As such you can get slowed by 60% by a Regulus Mark of the Betrayer. It wont stack with anything else though

That is odd. I can't see any way to explain it. Nice find.

Open character screen, then click the minimize button.

I thought this was how it worked but today I met a regulus who used main, wyrmskin and venom (favor) and my speed was lowered by 55% (from 6.3 to 3.5) so I now assume the OP to be correct.

6.3 * (1-(0.05+0.15+0.25)) = 3,465

which is rounded off to 3.5 so they did indeed stack. I made sure to ask the regulus if he had mark of betrayer and he said he didnt have it yet so MoB is ruled out of this. his allies were UB and Sedna and I doubt any of them had a 55% slow item/ability. escpecially since no such thing exists in the game atm.

So I figured Id take a little look at the code,

###############################################
# Buff: Poisoned Dagger
###############################################
BuffBlueprint {
    Name = 'AchievementSnareSlow',
    DisplayName = '<LOC ITEM_Achievement_0040>Poisoned Dagger',
    Description = '<LOC ITEM_Achievement_0042>Movement Speed reduced.',
    BuffType = 'ACHIEVEMENTSNARESLOW',
    EntityCategory = 'MOBILE - UNTARGETABLE',
    Debuff = true,
    CanBeDispelled = true,
    Stacks = 'REPLACE',
    Duration = 8,
    Icon = '/NewIcons/AchievementRewards/PoisonedDaggerofHate',
    Affects = {
        MoveMult = {Mult = -0.25},
    },
    Effects = 'Slow01',
    EffectsBone = -2,
}

##############################################
# Wyrmskin Handguards
##############################################
BuffBlueprint {
    Name = 'Item_Glove_040_Slow',
    DisplayName = '<LOC ITEM_Glove_0007>Wyrmskin Handguards',
    Description = '<LOC ITEM_Glove_0010>Movement Speed and Attack Speed reduced.',
    BuffType = 'ITEM_GLOVE_040_SLOW',
    Debuff = true,
    CanBeDispelled = true,
    Stacks = 'REPLACE',
    Duration = 5,
    Affects = {
        MoveMult = {Mult = -0.15},
        RateOfFire = {Mult = -0.15},
    },

    Effects = 'Stun01',
    EffectsBone = -2,

    Icon = 'NewIcons/Hand/Hand4',
}

###############################
# Maim I
###############################
            Name = 'HGSA01Maim01',
            DisplayName = '<LOC ABILITY_HGSA01_0012>Maim',
            Description = '<LOC ABILITY_HGSA01_0014>Movement Speed reduced.',
            BuffType = 'HGSA01MAIM',
            EntityCategory = 'MOBILE - UNTARGETABLE',
            Debuff = true,
            CanBeDispelled = true,
            Stacks = 'REPLACE',
            Duration = 3,
            Affects = {
                MoveMult = {Mult = -0.05},
            },
            Effects = 'Slow03',
            EffectsBone = -2,
            Icon = '/DGRegulus/NewRegulusMaim01',
        },
    },

}

What we can see is that all the abilities did add up to 55% which was what I used in my calculations

We also see they all have different names on their buffs which is needed in order to dissallow several maims from different reguluses stacking.

I failed to find the code however for the 33% max stacked slows though which dissalowed me to track down the bug itself.

I got strong feelings though that the code in question uses these debufftypes and that they simply forgot to add for example the (BuffType = 'ACHIEVEMENTSNARESLOW') which the favor venom uses to it. That would allow the venom to reduce your speed below 67% which is what is experienced.

Would be happy if this issue was forwarded to GPG so they could have a quick check of the code.

Who knows, perhaps its already in the "fixed list" for 1.01 due this tuesday.

if the 33% slow max is bugged for this I doubt the 25% max slow favor item works correctly either.

if this is the case, it is very disappointing. especially when the CEO of stardock tells everyone that there is a slow cap for the next patch.