Blog Posts from "WoW Mechanics" - Gameriot.com

Lethality: The Truth

no.spam@gameriot.com (briyan) — Mon, 08 Oct 2007 01:30:36 -0400

Lethality is a 5-point rogue talent on the third tier of the Assassination tree. 5 points in Malice (5% increased crit chance) and 10 total points in Assassination are required before you can take Lethality. Straight from the game, we can see the description as follows:

(5/5) Lethality increases the critical strike damage bonus of your Sinister Strike, Gouge, Backstab, Ghostly Strike, Mutilate, Shiv, and Hemorrhage abilities by 30%.

What does this mean in simple terms?

5/5 Lethality makes your spammable special attacks do 15% more damage when they crit.

Lethality gives a max of 15% increase to crit damage, not 30%

Many players mistakenly think their crits are being increased by 30% due to the wording of the talent ingame. Due to the nature of crit calculation, however, a 30% increase to critical strike damage bonus equates to only a 15% increase in the actual damage of the attack.

By default, an attack that hits for 100 will crit for 200.
This 200 crit is made up of two parts, 100 base damage and 100 bonus damage
For 5/5 Lethality, we increase the 100 bonus damage by 30%, giving us 130 bonus damage
100 base damage + 130 bonus damage = 230 total damage
230 / 200 = 115%, thus our crit now does 15% more damage
LethalityIncrease = 15%

Gotcha #1 - the bonus only applies to critical strikes

While 15% sounds like a solid number, you must keep in mind that this bonus from Lethality only applies to critical strikes. Based on the critrate of our special attack, we can calculate exactly how much of the damage comes from critical strikes. A simplified formula for the proportion of crit damage for a rogue is:

CritFraction = 2*CritRate / (1+CritRate)

To show you why this simple formula makes sense, we can look at an example of Sinister Strike with a 25% critrate:

With a 25% critrate, we expect one in four attacks to crit
We'll use example attacks of 100, 100, 100, 200(crit)
Damage from crits = 200
Overall damage = 100+100+100+200 = 500
CritFraction = 200 / 500 = 40%

Now let's plug the same example numbers into our formula, where CritRate = .25

CritFraction = 2*CritRate / (1+CritRate)
CritFraction = 2*.25 / (1+.25) = .5 / 1.25 = 40%

Given the fact that we know Lethality will increase our CritFraction by 15%, we can multiply them together to get the total DPS increase for our special attack (Sinister Strike in this case).

SpecialDamageBoost = CritFraction * LethalityIncrease
SpecialDamageBoost = 40% * 15%
SpecialDamageBoost = 6%

Gotcha #2 – special attacks are only a small fraction of your total damage

To truly gain perspective on how much your damage is increasing due to Lethality, you need to determine how much of your total damage comes from special attacks (Sinister Strike in our example). This is not really a concrete number, but one that must be measured by your performance ingame. From my own experiences and input from several other rogues over time, I can provide fairly accurate estimates of this number for the sake of our discussion.

Basic estimate for any given build/gear level = 35%
Combat rogue, Raid setting = 25% - 35%
Combat rogue, PvP setting = 30% - 40%
Backstab/Mutilate rogue, PvP setting = 35% - 45%

Particularly with raiding rogues, this number will tend to get smaller and smaller as your gear improves, since auto-attack is the strongest-scaling component of your overall damage with +hit gear, haste, and attack power. In PvP scenarios, the number tends to be slightly higher due to the stop-and-go nature of PvP combat, which can reduce the relative contribution of auto-attack and increase the opportunities to unload a full energy bar.

We'll call this number the SpecialFraction, as it represents the fraction of our total damage that comes from our special attack. We can multiply this by our SpecialDamageBoost to determine the overall boost to our damage from Lethality.

TotalDamageIncrease = SpecialFraction * CritFraction * LethalityIncrease

For an example, we'll use a Combat Sinister Strike rogue with a CritRate of 25% and a SpecialFraction of 35%.

TotalDamageIncrease = 35% * 40% * 15%
TotalDamageIncrease = 2.1%

Lookup table (PVE) – find how much 5/5 Lethality is helping you

I have created a table of values that will help you estimate what kind of a DPS increase you are getting from Lethality in a typical PVE scenario (i.e. no resilience). To find your number, choose the CritRate of your special attack on the left side, and choose the SpecialFraction across the top.

Lookup table (PVP) – 5/5 Lethality vs. 400 resilience

This second table uses the same principle as the one above, but it uses a modified formula that factors in the presence of 400 resilience (~10% critrate reduction, ~20% crit damage reduction) on your target. This is a nice round number that approximates the resilience of an opponent with full arena gear.

The new formula for CritFraction takes into account the critrate reduction and reduced crit damage:

CritFraction = 80%*2*(CritRate-10%) / ( 1+(CritRate-10%)*(80%*2 - 1) )

To find your number, again choose the CritRate of your special attack down the left and your SpecialFraction across the top.

The bottom line?

The moral of the story is that you should really think hard before you put any points into Lethality if you play a Sinister Strike build, particularly if your focus is PvP combat. While it is viewed by many as a "must have" talent in the Assassination tree for any build, I hope that some of these numbers can convince you otherwise. Giving 5 points to this talent for what will usually give you less than a 2% DPS increase may not be your best option, and could potentially be traded for some talents with "intangible" qualitites in the Combat or Subtlety trees.

If you are only interested in PvE raid damage, you will still want points in Lethality because there are no other alternatives that boost damage output, and Mutilate rogues have so many points into assassination that it makes sense to grab it anyway.

Expose Armor Exposed

no.spam@gameriot.com (briyan) — Sat, 29 Sep 2007 20:50:05 -0400

Expose Armor has really come into its own in TBC, as larger health pools, resilience, and powerful healing/delay tactics in arena have pushed rogues into longer fights and an emphasis on sustained damage. Given the complex formulas used for armor, however, it is not entirely obvious what sort of benefit you can expect from Expose Armor, or the Improved Expose Armor talent for that matter. My goal is to give you a more concrete feel for this finisher.

How does Expose Armor scale?

The formula for armor causes mitigation values to scale up quickly at first, and then slowly taper off as they reach the maximum value of 75% reduction. The nature of this curve causes Expose Armor to lose effectiveness as armor goes up. This means that Expose Armor is much more powerful against cloth-wearing classes, for instance, than plate-wearing classes.

What about Improved Expose Armor?

2 points in the Improved Expose Armor talent will increase the armor reduction of Expose Armor by 50%. Given the static values involved, this talent can give a significant DPS boost over the standard expose armor, but it also is less effective as your target's armor increases.

How much does my damage increase with Expose Armor?

While the in-game interface and tooltips do not offer any reasonable way to estimate the impact of Expose Armor, the nature of rogue damage makes it very simple for us to accurately estimate the damage increase from Expose Armor. The only rogue damage not affected by armor is poison damage and bleed damage, which generally make up a very small fraction of a rogue's damage (usually less than 5%, especially in longer fights). This means we can basically treat the reduced armor mitigation from Expose as if it buffs all of our damage.

A table of rough estimates appear below, you can find the damage increase against a particular class by looking it up in the table. Note: for Bear Druid, I tried to consider typical bear armor from Gladiator set, rather than a max-armor tank value.

Target Class	Base Armor	DPS Increase
Cloth, Rogue, Druid	4,000	8.93%
Hunter	7,000	7.08%
Plate+2H, Sham+Shield	11,000	5.55%
Plate+Shield	16,000	4.36%
Bear Druid	18,000	4.02%

You can see from the table that a Rogue with 2/2 Imp Expose will do approximately 9% more damage to a Priest under 5-point Expose than a Rogue without the talent.

More details available

I built a spreadsheet to calculate all these values, and I have made it available for you all to see at Google Spreadsheets if you are interested in a little more detail than I have posted in these sample tables.

View full spreadsheet here

Armor Penetration Breakdown

no.spam@gameriot.com (briyan) — Sat, 29 Sep 2007 18:58:30 -0400

Arena Season 3 is coming soon, and recent posts by developers have hinted that we will be seeing armor penetration included on PvP gear for the first time. This is a welcome addition to the item budget in the offensively weak PvP sets of physical DPS classes, but just how far does each point of armor penetration go?

Target Class 1000 pen
2000 pen
3000 pen
4000 pen

Cloth, Rogue, Druid
7.38% 15.93% 25.96% 37.89%

Hunter, Enh.Sham
6.04% 12.86% 20.61% 29.50%

Plate+2H, Sham+Shield
4.86%
10.23% 16.17% 22.78%

Plate+Shield
3.91%
8.14% 12.73% 17.73%

Bear Druid
3.38%
7.00% 10.89% 15.06%

*According to Kalgan on WoW forums, the ful set of Season 3 gear will have something less than 910 Armor Penetration.

I have created a full spreadsheet that will allow you to look up these values by target armor value and amount of armor penetration, and I have it hosted for public view at Google Spreadsheets.

View the full spreadsheet here

Target Class	1000 pen	2000 pen	3000 pen	4000 pen
Cloth, Rogue, Druid	7.38%	15.93%	25.96%	37.89%
Hunter, Enh.Sham	6.04%	12.86%	20.61%	29.50%
Plate+2H, Sham+Shield	4.86%	10.23%	16.17%	22.78%
Plate+Shield	3.91%	8.14%	12.73%	17.73%
Bear Druid	3.38%	7.00%	10.89%	15.06%