View Full Version : DPS Sunder Armor(possibly FF) and ArP

04-13-2010, 12:13 AM
It was my understanding that sunder armor and ArP were based on the same armor %...

to clarify - I thought that sunder armor reduce the boss armor by 20% and then ArP % was based off of what was left after sundering.

so if a boss had 100 armor and you sunder - hed have 80 left and then..if u had 90% ArP ..you reduced that 80 by an additional 72(90% of 80)..leaving you with 8 armor. By this logic having 100% ArP would essentially be the same as having no warriors to sunder?

if that is correct - why does my spreadsheet/Rawr stil increase my DPS by ~600 with sunder selected as a debuff when I'm at 100% ArP?

or Does sunder work on some other base Armor that ArP doesnt interfere with? I'm confused.:confused:

04-13-2010, 12:24 AM
sunder armor is armor REDUCTION not armor PENETRATION.

04-13-2010, 12:26 AM
sunder armor is armor REDUCTION not armor PENETRATION.

wow that was simple...I never looked at it from such a base line POV.

04-13-2010, 06:41 AM
It might be an error in Rawr's equations, or you might be missing something and not be actually at 100% ArP.

I know there was a trick before where you could actually go over 100% ArP and still get increase in damage, but I thought they had fixed that so it wouldn't be the case. Maybe someone else here knows the math better.

04-13-2010, 08:53 AM
I forget the specifics of it, but it was my understanding that armor pen only worked on a portion of the target's armor. So if a target had 100 armor, armor pen would only work on lets say 80 of it. So with 100% armor pen your target would be considered to have 20 armor. Sunder armor and FF like effects work on the total armor though, so if your hitting a target with your 100% ARP and fully debuffed it would only have 15 armor.

04-13-2010, 09:01 AM
Quote from: Ghostcrawler (Source)

Okay, here is a fairly technical explanation we put together for how armor pen works.

We didn’t want Armor Penetration Rating to be too powerful against low armor targets, like it had been in BC. We also didn’t want Armor Penetration Rating to be too powerful against high armor targets.

So, we decided on a system where there is a cap on how much armor the Armor Penetration Rating can be applied to. So, the first X armor on the target is reduced by the percentage listed in the Armor Penetration Rating tooltip, and all armor past that X is unaffected. Another way of understanding that is we multiply the percentage in the tooltip times the minimum of the two values: the cap, and the amount of armor on the target after all other modifiers.

Computing the cap is a little tricky unless you are already familiar with how World of Warcraft armor works. There is an armor constant we’ll call C. C is derived as follows (in some pseudocode):

If (level<60)

For a level 80 target, C=15232.5. For a level 83, C=16635.

The cap for Armor Penetration then is: (armor + C)/3.

A level 80 warrior creature has 9729 armor. C=15232.5. So, the cap is (9729+15232.5)/3=8320.5. Let’s say a player has 30% armor penetration from armor penetration rating and no other modifiers that complicate the calculation (talents, Battle Stance, Sunder Armor, etc.). The game chooses the minimum of 8320.5 and 9729, so 8320.5. That is multiplied by 30% = 2496.15, and so that much armor is ignored. The effective armor on the target is 7232.85 (9729-2496.15). From a player point of view, the armor penetration rating didn’t ignore the full 30%, but instead ignored 25.66%. (85.5% as effective as expected).

These equations should help you be able to test and verify that Armor Penetration Rating is working correctly and as we designed. The tooltip is not actually inaccurate, as it states: “Enemy armor reduced by up to 30.00%.” That "up to" is key.

Please be sure to test without any other effects which modify the armor calculation (Battle Stance, Sunder Armor, Mace Specialization, etc.) as they may involve other systems that add additional complexity to the calculation.

The formula for the Armor Penetration cap can be simplified to ArPcap = (935/6)*x + y/3 -44335/6, where x is the target level and y the target armor. Then effArmor = targetArmor - ArP * min{ targetArmor, ArPcap} as explained above, with the Armor Penetration ArP of your character. ArP is given, lately changed in 3.1.2[2], by the formula ArP = min{ 1,(Sum ArPcontributions)%}.

Calculating the ARP it's done in 2 parts:

First up - the debuffs. These reduce your target's initial armor. For example, if your target has 10k armor and it gets 20% sunder, its armor would be 8k. The debuffs stack additively, so Faerie_Fire will stack with sunder, totaling a 25% reduction on the target, taking it to 7.5k armor.

Second, comes the formula GC provided, you grab the armor after the debuff calculation and to that armor you apply the formula (armor + C)/3. Using the same example as before, lets say the target is level 80, so C=15232.5, now calculate (7500 + 15232.5)/3 = 7577.5. This makes the target's armor lower than the result, meaning that each 1% removes 750 armor and you are hitting a 0 armor target on the 100% ARP get. The ArP "buffs" (items, stances and such) stack additively too, meaning that 90% ARP on battle stance for a warrior would mean a 100% ARP final.

04-13-2010, 03:42 PM
That's not entirely perfect, but it's close.

In any case, the most important things to note are that sunder and FF stack multiplicatively, not additively - and that armor penetration's percentage is based on whatever's left after sunder/FF apply. And against lvl 83 bosses with the standard 10643 armor, there's a bit of armor that you can never remove, no matter what - which makes shattering throw actually do something.

Muffin Man
04-13-2010, 05:05 PM
Let's see if I can summarize

There's a cap on armor *penetration*

So you use armor *reduction* to reduce a mob's armor below the cap.

04-13-2010, 05:34 PM
yes there is a cap on penetration, once you reach 100% that's it, if you go 101% that 1% is wasted, because that formula won't take past 100%

but there is a CAP based on the current armor of the target, that is ALWAYS > 0 except when shattering throw is up. SO, sunder armor, increases dps, even if at 100% ArP because you reduce the effective armor of the boss.

here's the math:

10643 base armor for most bosses at level 83, therefore we use the formula for C = 400+85*83+45*85*(83-59) which gives you 16635 as provided by GC.

(10643 *16635) / 3 = 9092.7 is the max armor you can reduce from a boss. so even at 100% arp, with no sunders, the boss will have 10643 - 9092.7 = 1550.3 armor left over.

now lets look at sunder armor values

10643 * .8 (20% reduction) = 8514.4 effective armor, (8514.4 + 16635) / 3 = 8383.13 armor you can reduce. With 100% ArP, 8514.4 - 8383.13 = 131.27 armor left over.

Therefore, even at 100% arp, sunder armor saw a 1300+ armor reduction overall in the bosses armor, and REMEMBER, that armor scales exponentially in reverse. So that last 1300 armor reduction is more effective than the first 1300 you remove. 5% additional from improved faerie fire just further brings this down, and finally shattering throw should bring that number down to near 0.

So do you sunder armor? Yes, do you FF? yes, do you shattering throw yes. Do you still want 100% arp? Absolutely. End of Discussion.

04-14-2010, 06:59 AM
Well done sir, very informative.

04-14-2010, 09:35 AM
Hey, I took 3 years of math courses, I'm not THAT bad at math =P

04-14-2010, 01:37 PM
Kaz and others all hit the point. "100% ArPen" isn't a 100% penetration of the target's armor. That 100% is just the maximum, or hard cap, for that particular ability.In reality though, it does not completely eliminate a target's armor. Saying it's 100% armor penetration is somewhat misleading in that sense.

ArPen Table: http://www.wowwiki.com/Armor_penetration
This lays out probably in the most clear sense what the real values end up being if you want a quick glance as to how it works.

As you can see at the very bottom right part of the table, 99.9% at an armor pen value of 1230 reduces a boss with 50k armor down to an effective 27806. Certainly NOT a 99.9% reduction in armor value.

Sunder armor adds to it though, thus "stacking" with arpen essentially.

Yes Kaz, your math is spot on. And it's really not calculus or anything really all that challenging. I think the issue is really that, when we see armor penetration reflected as a percentage, we're somewhat misled into thinking THAT is the amount of armor negated, when it really isn't.

04-14-2010, 02:21 PM
Agreed, but are there any bosses that realistically have 50k armor? I'm pretty sure the range only goes from 10k to about 16k max.

04-14-2010, 04:25 PM
Agreed, but are there any bosses that realistically have 50k armor? I'm pretty sure the range only goes from 10k to about 16k max.

Correct. Last I checked and saw anything reliable (Elitist Jerks), boss armor was around 10-11k. That was also about a year old so might be higher for ICC. Still going by the chart, even at 10k, 1129 armor at 99.9% still isn't blasting through 99%+ of the boss's armor, suggesting that the translation isn't 1:1. That's still 10% remaining.

Of course.... if you're walking around with an ArPen of 1230..... O_O

04-14-2010, 05:08 PM
I'm capped for ArP for sure, as are a lot of top dps fury warriors (i'm arms). It's pretty awesome =]

04-15-2010, 04:43 AM
armor_penetration=min((∑ talents)+(ArPR/rating_coeff)/100,1)
armor_constant=467.5*attacker_level-22167.5 [given that level>60]
effective_armor=debuffed_armor-armor_penetration*min(debuffed_armor,(debuffed_arm or+armor_constant)/3)

- all WotLK boss-level targets have 10643 base armor (post-3.1)
- shattering throw stacks with both major/minor ArP debuff classes
- the armor constant of the defender is computed for a certain level of the attacker; considering a level 80 PC against a level 83 NPC : c_pc =16635 (NPC attacking PC), c_npc=15232.5 (PC attacking NPC)
- the effects of all ArP-granting talents* are additive (respectively : battle stance+mace spec, serrated blades+mace spec, blood gorged) [post-3.3.3, serrated blades affects armor penetration, instead of debuffed armor]
- the value of the ArP rating coefficient is ~13.996 (post-3.2.2), so the cap (excluding the talents) is reached at 1400

04-15-2010, 06:33 AM
- all WotLK boss-level targets have 10643 base armor (post-3.1)

This. Boss Armor has been made constant across the board. Unlike BC where Loot Reaver had much more armor than most bosses.

06-25-2010, 12:42 PM
- the armor constant of the defender is computed for a certain level of the attacker; considering a level 80 PC against a level 83 NPC : c_pc =16635 (NPC attacking PC), c_npc=15232.5 (PC attacking NPC)

this is the part that confuses me more than anything. GC's post seemed to indicate that C was based on your target's level, but many people are claiming it's based on the attacker's level.

assuming i want to know how much of a boss' armor i can reduce, which is it and how do you know?