Change log
There has been some discussion in the discord channel recently on how exactly the double http://www.wowhead.com/spell=30455/ice-lance" target="_blank works. Some players were reporting 100% success rates and others 0%. Before we continue, let's look into what exactly double http://www.wowhead.com/spell=30455/ice-lance" target="_blank is.
What is double Ice Lancing
Double Ice Lancing is the method of fitting 2 http://www.wowhead.com/spell=30455/ice-lance" target="_blank into the http://www.wowhead.com/spell=228358/winters-chill" target="_blank debuff applied from a instant cast http://www.wowhead.com/spell=228354/htt ... 354/flurry" target="_blank proc (http://www.wowhead.com/spell=190447/brain-freeze" target="_blank proc). This also requires [/size]us to stand closer to the boss than you may be used to to offset the travel time of the http://www.wowhead.com/spell=30455/ice-lances" target="_blank themselves.
The rotation is simply:
http://www.wowhead.com/spell=228354/htt ... 354/flurry" target="_blank (with http://www.wowhead.com/spell=190447/brain-freeze" target="_blank proc) -> http://www.wowhead.com/spell=30455/ice-lance" target="_blank -> http://www.wowhead.com/spell=30455/ice-lance" target="_blank
Doesn't this require a lot of haste?
Hell yeah it does. Luckly, we have multiple ways of buffing our haste significantly: http://www.wowhead.com/spell=12472/icy-veins" target="_blank and http://www.wowhead.com/spell=80353/time-warp" target="_blank (Troll racial http://www.wowhead.com/spell=26297/berserking" target="_blank). It is also possible to obtain with the http://www.wowhead.com/item=140809/whis ... bonus=3515" target="_blank trinket but since it's proc rate is somewhat elusive, the easiest way to obtain the required haste is through http://www.wowhead.com/spell=12472/icy-veins" target="_blank and http://www.wowhead.com/spell=80353/time-warp" target="_blank. Below is a graph showing haste breakpoints / Distance from target.
All Credit to Architech
So why did you mention world ms/input tolerance then??
I'm glad you asked. Input Tolerance is the amount of time the server uses to queue up your next spell while your current spell is casting.
0 ms Lag Tolerance means you have to hit the spell EXACTLY when the previous spell has finished/gcd is reset. This is obviously not possible since we are not robots and also not sat on top of the server cluster so Input Tolerance is used to remove as much of this human error as possible (with a spell queue system).
400ms uses the actions you pressed in the last 400 milliseconds as the amount of queue time. So, if I hit http://www.wowhead.com/spell=30455/ice-lance" target="_blank with 400 milliseconds left on my previous cast/gcd, it will queue up and cast an http://www.wowhead.com/spell=30455/ice-lance" target="_blank when next available.
Great, why does any of this matter?
When I first heard about the double http://www.wowhead.com/spell=30455/ice-lance" target="_blank, I was unable to reproduce it. I tried multiple haste break points and different distances to the target. All failed. I was doing exactly what others were telling me and still failed.
However, further testing proved that the issue didn't lie in the order of actions but in the Lag Tolerance. I currently play with a lag tolerance of 30ms. As fire, I could perform very well but could simply not reproduce this double http://www.wowhead.com/spell=30455/ice-lance" target="_blank. Other higher ranking fire mages were also in the same boat (Dutchmagoz-Senpai).
The issue we ran into was that we were unable to activate the spells fast enough. 30ms input tolerance was simply too strict even with mass key down action spamming of http://www.wowhead.com/spell=30455/ice-lance" target="_blank. By simple increasing our input tolerance, we were able to achieve 100% results. Below are logs demonstrating this effect:
Credit to Dulcane for providing logs while I wrote this.
0ms Input Tolerance
200ms Input Tolerance
You see that with 0ms, the 2nd http://www.wowhead.com/spell=30455/ice-lance" target="_blank which is cast ~.9 seconds after the first, does not gain the effects from Winter's Chill.
With 200ms, the 2nd http://www.wowhead.com/spell=30455/ice-lance" target="_blank hits ~.8 seconds after the first and DOES gain the Winter's Chill effect.
This minute amount of time difference results in both a loss of damage AND uptime of http://www.wowhead.com/spell=12472/icy-veins" target="_blank through the http://www.wowhead.com/spell=80353/time-warp" target="_blank talent.
Video Examples:
How do I change my Input Tolerance?
Blizzard removed the default option but it can be accessed again via this addon:
https://mods.curse.com/addons/wow/advan ... aceoptions
Once installed, follow this step by step:
Interface -> Addons -> Combat -> Custom Lag Tolerance
Others have reported you may also have to run this command to activate the Lag tolerance itself.
/console SetCVar("reducedLagTolerance", 1)
Conclusion
While this method will no doubt grant you extra dps, it is also much more of a hassle to pull off in a real world situation. Due to the 15 yard constraint of shatter Ebonbolt, there is an added element of 5-15yard "dancing" to maintain the double http://www.wowhead.com/spell=30455/ice-lance" target="_blank during Lust. It does add another level of thinking to the spec but ultimately, I believe is a design flaw and should either be baked into the spec without the range requirement, or removed entirely.
Check List/TL:DR
Configure Input Lag Tolerance to desired amount (75ms works for me but different for everyone)
Get required amount of haste.
Stand within 0-15 yards of the boss.
Pop http://www.wowhead.com/spell=12472/icy-veins" target="_blank + http://www.wowhead.com/spell=80353/time-warp" target="_blank
Get http://www.wowhead.com/spell=190447/brain-freeze" target="_blank proc
Cast http://www.wowhead.com/spell=228354/flurry" target="_blank
Cast http://www.wowhead.com/spell=30455/ice-lance" target="_blank
Cast http://www.wowhead.com/spell=30455/ice-lance" target="_blank
Both http://www.wowhead.com/spell=30455/ice-lances" target="_blank shatter and also extend the duration of http://www.wowhead.com/spell=12472/icy-veins" target="_blank through http://www.wowhead.com/spell=155149/thermal-void" target="_blank (even though they are not affected by http://www.wowhead.com/spell=112965/fingers-of-frost" target="_blank). Op stuff.
Disclaimer
If you already run wow with high world ms, this may not affect you since your input tolerance is already high due to the time your actions take to register with the servers. The one time high ms was not a bad thing