Simple ArPen calculator


for WoW Patch 3.3.3
Target Armor   
Player Level
ArPen from gear in %
* 5x Sunder Armor (-20%)
* Faerie Fire (-5%)
* Shattering Throw (-20%)
Effective Armor
+ Battle Stance (-10%)
+ Mace Specialization (-15%)
+ Hearty Rhino (40 rating = -2.8%)
+ Elixir of Armor Piercing (45 rating = -3.2%)
+ Incisor Fragment proc (291 rating = -20.8%)
+ Bonereaver's Edge procs (300 rating = -21.4%)
+ The Dusk Blade procs (465 rating = -33.2%)
+ Grim Toll proc (612 rating = -43.7%)
+ Mjolnir Runestone proc (665 rating = -47.5%)
+ Needle-Encrusted Scorpion proc (678 rating = -48.5%)
+ Executioner proc (120 rating = -8.6%)
Target Armor, capped
-
Target Armor, uncapped
-

Changelog:

Tiny update adding the Needle-Encrusted Scorpion and bumping the patch version number supported.



Armor Penetration rating modifier is getting nerfed in patch 3.2.2, see this post: Armor pen nerf in 3.2.2 by Ghostcrawler. This was discovered by Aldriana and Whitetooth here: Elitist Jerks - Combat Ratings at level 80.



The current rating modifier is 12.31623993, the new one will be 13.99572719. I've updated all values in this calculator to reflect 3.2.2, which introduces a 12% nerf to ArPen rating.



Oh and there is of course a cap to player procs/buff, it is 100%.



Target debuffs was set as additive when they should have been multiplicative. This is now fixed.



Calculator updated after Ghostcrawler released the armor penetration formula. And no, there is no armor penetration cap, it is possible to stack enough player buffs to bring the target to negative armor.



The smarts at EJ forums finally nailed the PTR bug with ArPen. See [BUG] PTR ArP exactly 19% worse than tooltip for more information.



Changed all percentage based modifiers to be multiplicative and all rating based modifier to be additive. I'm hopefully going to be able to do some futher tests on PTR tonight.



The legend for the ArPen options on the left should be somewhat obvious, but I'll clarify them here anyways:
* means multiplicative, + means additive.



I was messing around with numbers to see what and what wouldn't match the results of various peoples numbers. Not much luck! :)