chill = negative ias?


Diabloii.Net Member
chill = negative ias?

im trying to ucover the mechanics of chill/slow/hf on players attack speeds
this is for pvp reasons

i not sure but i sorta guess the slow effect combines into ones eias.
the amounts are linear? wich means -1%hf = -1%slow

cold/chill is a set amount, but how much is it?

and if i needed to figure attack speeds with chill amounts is there a calc out there that can allow me to enter this change somehow?


Diabloii.Net Member
Attack breakpoints come about by a division in a quite large computation. The denominator in this division is your "speed" in a sense.

It is made up of
100 (your base)
+ skill IAS (such as Fanaticism)
+ EIAS (diminished equipment IAS)
- WSM (your weapon's base speed).
This is capped above at 175 and below at some number I can't currently recall (25?)

When you are slowed, by say 25%, it multiplies the first two components above by a modifier, in that case 0.75. So if you have no Fanat or anything like that, it will simply reduce your speed by 25, the same as if you were using a 25 slower weapon. If you have say 20% from Fanat, you will lose 25% of that too, so in this case you'd drop by 30 (from 120 to 90).
How many frames that drops you is depenedent on a lot of other things.

Finding a calculator online that does this accurately is unlikely, I'm afraid.


Diabloii.Net Member
thank you for this info thrugg. i need to confirm i have it right though

the first "2 components" as u said... those are base(100) and ias?

from a -25% slow u loose -25% of base to get 75.
ur ias takes a 25% reduction.
EIAS from skills gets lowered by the 25% as well.

so this isnt so hard to understand now,, as long as i got it right
x = the amount of slow

base -X%
eias (if any) -X%
(ias-X%) convert into eias

plug these 3 amounts into the EIAS formula to derive ur finall eias and check tables?

now can u give me,, (or point me in the direction to find) a listing of Xslow amounts from certain cold skills? (HF excluded)

are all COLD spells/effects the same slow amount?
shiver armor = -25%?


Diabloii.Net Member
Only your base and skill IAS are affected. Your EIAS is retained in full.
Note the caps are still there (15 and 175, I checked).

I'm afraid slow effects have never been my specialty however, so I can't tell you off hand how much things slow you by unless it is described on the item. RTB might be able to help you find those.


Diabloii.Net Member
Jerkazoid said:
are all COLD spells/effects the same slow amount?
shiver armor = -25%?
Yes, and it's -50% for players/minions/mercs AFAIK. Monsters have their own values.

There's also some info on slow% found here. Note that the bug with slow% has been fixed.


Diabloii.Net Member
Thrugg said:
AIf you have say 20% from Fanat, you will lose 25% of that too,
ok just to be sure

u said here that fanatas eias takes the hit as well?. but then u said only base + ias takes the penelty

can i get 1 last confirmation on wich it is?

ok RTB ; so chill/shiver armor = -50% vs players

the link is partially helpfull TY but its about r/w so its not quite providing me with answers

it seems many are under the impression slow is capped at -50% total, but i did some tests and it seems that although that might be true for single source, multiple sources of slow do seem to combine up to make effective slow greater.

i decrepified, golem slowed, and chilled myself and went from a 1 sec vollley of 7 kicks to a 3 second volley of 7 kicks
this was with about 30bos, 60ias +flail.

so 15 and 175 thrugg? this means the max slow effective is -85% of base speed ? and max speeds are capped a +175%?
or are u saying only the (base 100) can be modified to 15 through 175

are u just leaving out "%" that confuses me, i get confused easily


Diabloii.Net Member
I believe I said only base and skill IAS are modified - and the only kind of skill IAS I can think of is Fanaticism (maybe wereform too? never really researched wereform speeds).

Your EIAS, the diminished IAS from all the gear you wear, is not modified.

The 15 and 175 caps are on the total sum of all 4 components of the speed. That sum can be thought of as a percentage speed modifier of the base length of the attack animation. Which means in theory you should be able to slow someone down to ~6 times as long to make each attack as base. However, you almost never see anyone attacking at base anyway (unless they use a 0 WSM weapon and have 0 IAS) so it is not easy to measure empirically.

An example or two might help. Suppose you have a guy wielding a Lightsaber with no other IAS on him. His speed is 100+0+17+30=147 (17 is the diminished 20 IAS on the Saber and 30 is the negative of the Phase blade WSM). Which means each attack he makes takes around 68% (100/147) of the length of the base animation for his class wielding a 1H sword (which varies from class to class). The fact that frames are in integers is where breakpoints come from.

If you chill/slow/golem this guy, I'm not sure how far you can reduce the base by - maybe even down to 0 (not sure here) - but he is still going to have at least 0+0+17+30=47 speed left, because you can't slow down EIAS or WSM. At that speed his attacks will take 100/47 or about 212% as long as the base attack - which is only about three times as long as he was unchilled (68%).

The 15 lower cap is on the total sum, which makes it near impossible to reach with a fast weapon. EIAS can never be negative. But, if someone was wielding a slow weapon like a Great Maul with a high positive WSM, they may well hit the cap if they aren't wearing much IAS. At that point their attacks would indeed take 6 times as long as the bas animation for their class with that weapon type.

Moral: don't get chilled and slowed while wielding a Great Maul with no IAS :lol:

Likewise at the high end, you can't ever get above 175, ie 175% faster than the base animation, even with a super fast weapon and stacks of IAS. That's exactly why weapon speed charts always have a max somewhere, that corresponds to you exactly hitting that cap.


Diabloii.Net Member
that was fantastic

jrich said
"Skill_IAS refers to the bonus given to attack speed by BoS or Fanaticism."

so bos is ofcourse a part of skill_ias that gets hit by slow.
(for some reason i thought fanata% and bos% = eias amounts)

fpa = {(256*DrawnFrames) / [(AnimationSpeed*(base + EIAS-penalty)/100)]}-1

i dont quite understand where i find out what my "drawnframes" is nor "animationspeed"

base + skill ias + ias + wsm = speed
where "base" and "skill ias" are effected by the -slows amounts

dragon talon kicks with
-20talons 10%ias and 2bos (27%)

=skill ias -wsm + ((120*ias)/120+ias))
= 27 +20 +((120*10)/(120 + 10))
= 47 + 9
= 56 EIAS

fpa = {(256*DrawnFrames) / [(AnimationSpeed*(base + EIAS-penalty)/100)]}-1

fpa = {(256*DrawnFrames) / [(AnimationSpeed*(100 + 56-penalty)/100)]}-1

this is where i get stuck bc i cant fill in the blanks.

but i add 50% slow from chill and i get:

=skill ias -50% -wsm + ((120*ias)/120+ias))
= 27-50% +20 +((120*10)/(120 + 10))
= 47 + 9
= 42 EIAS

fpa = {(256*DrawnFrames) / [(AnimationSpeed*(100-50% + 42-penalty)/100)]}-1

so i think i got it right, right?,, but i cant figure out how to fill in the blanks

{im trying to edit one of Jrichs excel sheets to add a place to calculate slow..wait is animation speed = 256 always? im having trouble decoding}

he lists kick as 12 fpa base in the calc so thats where the draw frames might be comming from?

lets just post an example

0 wsm 0ias 0 bos
= 12/4

im getting 25/4 (hmm that cant be right)

-20wsm 25ias 2bos = 7/2 (ok so its a old calc before the 7/3 was figured)
with -50% slow = 12/3 well.. id have to test in game to confrim that.

man i didnt think it would still be this hard for me

anyone else help?


Diabloii.Net Member
Oh yeah, BoS, forgot that one (I hardly ever play assies).
Fanat and BoS are equivalent to EIAS (in that they are equally valued) except that they get slowed and EIAS doesn't.

So I was waiting for the ol' equation to come out :) OK, let's look at it:

fpa = {(256*DrawnFrames) / [(AnimationSpeed*(base + EIAS -penalty)/100)]}-1

DrawnFrames is the full length of the animation, in frames, for your class wielding your weapon type. For example, there is a "Paladin 1HSword" animation that has a certain total length, if you are a pally wielding any kind of 1HS then you use that animation and DrawnFrames is that length.
You can't look these up easily, they have all been cracked out of the animation files and you can maybe hunt them down with a net search. Speed calculators generally hard code them in.

Attacks get sped up or slowed down by omitting or repeating frames in the animation so that they are the length given by fpa above.

AnimationSpeed is almost always 256, but they could vary it if they want (some skills do, such as attacking as a Trang-Oul Vampire it is only 176 which is why they seem so slow). The two 256s cancel eachother out in real arithmetic but remember D2 is all integers - they result in extra precision which is very important (or the breakpoints would be even bigger).

Penalty is just rearranging the modifier I talked about. If you are slowed 25%, then rather than writing it as (100+skillIAS)*0.75+EIAS-WSM, you could call it 100+(skillIAS+EIAS)-(WSM+(100+skillIAS)*0.25) and it's still the same amount. I think the latter way is closer to the order the computer actually calculates it in.

OK, I shall now reveal myself as a total assy noob by asking if kicks are more like a Zeal or Fend attack than a normal attack (ie a first one followed by several fast ones)? Those kinds of attacks are handled a little differently, I'm afraid. There is this additional element called "rollback" that goes into the equation here: {(256*(DrawnFrames-rollback))...
Rollback is actually always there, it is just 0 for most attacks. But not for these rapid hit ones. It more or less works by the subsequent attacks not going all the way back to the start of the animation, just "rolling back" some of the way. Rollback is defined separately for each skill. I don't know what it is for Kicks :(

I am not allowed to point you to some places where you can learn more about this. That is a kind of hint.


Diabloii.Net Member
such info was my suscipsion

DT is a 100% roll back skill, jrichs post sorta gets into it but it wasnt enough for me to figure how to change his old excel sheet calc all the way. i asked on other sites if anyone else is able to help. no luck