Saturday, November 10, 2007

Rogues and Armor Penetration

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There have always been abilities that have reduced your target's armor, and, there has been gear that has allowed you to ignore your opponent's armor, primarily from high level instances like Black Temple, but it is my opinion that with Patch 2.3, Armor Penetration will be considered by more and more players.

Rogues aren't the only class that is going to get Armor Penetration. All melee classes are getting it. However, Rogues also have the Expose Armor ability and Serrated Blades talent in our Subtlety tree. As many Rogues are going Subtlety, I thought I'd give a quick rundown on how Armor Penetration works and what sort of improvement you're going to see from it.

First, you need to realize that some of our attacks don't even consider armor. So, for the rest of this post when I talk about DPS, I'm speaking of DPS that is affected by your target's armor.

Here's a list of the damaging abilities we possess that don't consider armor:

  • Garotte
  • Rupture
  • Poisons
  • Envenom

Next, how does Armor work? At level 70, World of Warcraft uses the following formula to determine a character or NPC's damage reduction (or mitigation) from armor.

Damage reduction =        Armor       
(Armor + 10557.5)

Thus, the more armor you have, the less damage you take from attacks. Makes sense, right? Stacking on more armor has a diminishing return effect for the increase to your mitigation. However, your increase to your time to live remains constant as you add armor. For each 1000 armor, you increase your TTL (time to live) by 9.47%. Damage mitigation from armor is capped at 75%, so having more than 31672.5 armor doesn't gain you anything.

How does Armor Penetration work? It simply removes armor from your opponent and recalculates their mitigation before your attack. If your opponent has 7700 armor and you have 1500 Armor Penetration, they only have 6200 armor versus your attack. They go from 42.2% mitigation to 37%. Therefore, you've increae your damage against them by 5%.

With Patch 2.3, Rogues are receiving 11 new pieces of gear that will feature Armor Penetration.

SlotNameSourceArmor Penetration
BackDory's EmbraceBadges of Justice112
WaistBladeangel's Money BeltZul'Aman77
RangedAncient Sin'dorei LongbowZul'Aman126
FingerSignet of Primal WrathZul'Aman126
ChestShadowtooth Trollskin CuirassZul'Aman210
MH WeaponProwler's StrikebladeZul'Aman140
MH WeaponDagger of Bad MojoZul'Aman140
MH WeaponVengeful MHArena49
OH WeaponVengeful OHArena49
HeadVengeful Gladiator's Leather HelmArena84
LegsVengeful Gladiator's Leather LegguardsArena84
FingerVindicator's Band of TriumphArena56
ChestVengeful Gladiator's Leather Tunic Arena84
Total Max from Gear 1155

That's a lot of gear being introduced that has Armor Penetration. You can get about 1200 Armor Penetration. But you are probably wondering, "How does that correspond to DPS?" Well, after a bunch of math, I came up with the following graph:

Click for an expanded chart.

The way to determine you DPS increase from Armor Penetration is first find your Armor Penetration total on the bottom (x) axis. Then, find the line corresponding to your target's current armor total.


So, say you have 1715 Armor Penetration (1155 from the gear above and another 560 from Serrated Blades) and your opponent is a boss in Serpentshrine Cavern that you know currently only has 3690 Armor because Warriors applied 5 Sunder Armors (-2600 Armor), Druids cast Faerie Fire (-560 Armor) and Warlocks applied Curse of Recklessness (-800 Armor).

Find 1715 on the bottom axis and then finding the 3000 and 4000 armor lines. 3000 is near 11% and 4000 is near 9.5%. So, I'd guess about a 10% boost to DPS. The actual value is 10.14%.

A couple of quick facts arise from analysis at this data:

  • The more Armor Penetration the better. It's not a diminishing return, but rather an increasing return.
  • The less armor your target has the greater benefit you get from Armor Penetration and every additional point of Armor Penetration.
  • Every ability that your team uses to reduce your target's armor helps your Armor Penetration.

Outside of gear and Serrated Blades, we also have Expose Armor and the corresponding talent Improved Expose Armor. Expose Armor negates 410 armor per combo (512.5/615 with each points of Improved Expose Armor respectively). This doesn't stack with a Warrior's Sunder Armor and is the reason why it isn't widely used. However, if you examine the graph for a 2050 Armor Penetration (normal 5 combo point Expose Armor), you can see that you're getting 7-16% increase in your DPS once applied and, with a Rank 2 Improved Expose Armor, you're applied a 3075 armor debuff for a 11-22% increase in DPS.

Also new in Patch 2.3, the Executioner Enchant can be applied to any weapon and will occasionally proc the Executioner self-buff which will add 840 Armor Penetration for 15 seconds. These do not seem to stack and they have been reported to proc about the same rate as Mongoose, or about 1 proc per minute. Most reports I've seen seem to report that Executioner will result in lower DPS than Mongoose, but these tests seem to be judging Executioner vs Mongoose in a vacuum of many of the other factors that are going to come into play during both Arena and PvE.

Here's a few more items that I found that have Armor Penetration:

Icon of Unyielding Courage
Binds when picked up
Requires Level 70
Equip: Improves hit rating by 30.
Use: Your attacks ignore 600 of your enemies' armor for 20 sec.
Warp-Spring Coil
Binds when picked up
Classes: Rogue
Requires Level 70
Equip: Improves hit rating by 21.
Equip: Your special attacks have a chance to give you 1000 armor penetration for 15 sec.

As I go into Patch 2.3, I plan to evaluate this firsthand and I'll report back with what I find. I would love to hear other Rogues' encounters with Armor Penetration as well.


Pawan said...

Great! Very informative, thank you! Cleared up all my questions regarding this change. I am going to pick up imp exposeA as well .. already have serrated.

Phaelia said...

Best article yet!

Valenna said...

@Phaelia: Thanks!

@Pawan: You're welcome! I struggled with what Armor Penetration was going to mean for my play and I ultimately wanted a +DPS number instead of a +DPS% number to come out. However, as I worked through the numbers more I understood that it was too dependant on the current armor of your opponent.

I'll be heavily considering Expose Armor myself. =)

Doomilias said...

very good article. i came up with alot of the same numbers recently as i was trying to figure how the new hemo will stack against ss (before i found out hemo is now normalized).

i still wouldnt recommend imp EA for a raiding build for the very reason that it will be negated or even come up with the message "a more powerful spell is already active" with 5 sunders applied. plus active armor reduction (not armor ignorance) is generally a high threat generating ability.

either way, very nice write up. i think blizz will continue to develop armor pen/ignorance, as it seems they are trying to give an alternative to attack power, which is an offensive stat that does not scale very well.

Anonymous said...

according to that graph the lower armor your target has the lower % increase your dps will get from the same armor pen.
Quote : "Find 1715 on the bottom axis and then finding the 3000 and 4000 armor lines. 3000 is near 11% and 4000 is near 9.5%. So, I'd guess about a 10% boost to DPS. The actual value is 10.14%."

If you take that example and exchange the tagets armor with a lower value you get a worse dam increase = 7-8% wich doesnt add up with your info.

you must have reversed the numbers on the vertical column? or the graph is just bullocks all together ?

Valenna said...

@Doomilias: Thanks!

@Anon: Thank you for your analysis! I want the article to be accurate so I welcome any criticism that leads to that end.

However, maybe you misread the graph? The bands of lines on the graph going from light blue to dark blue are the target's current armor values. The lightest and highest band corresponds to if your target has 1000 armor, the percentage of their armor caps at 1000 Armor Penetration where you have negated all 8.65% of their armor. As you gain more Armor Penetration, you move from the left of the graph at zero to the right of the graph closer to 3000. Going up higher into the graph determines what percentage of their armor you have negated. Send me an email at parryspindodge at gmail dot com if you have further questions or if you think there's something else I'm missing.