In World of Warcraft, the mechanics of combat are intricate and complex. Many different elements all blend together in even the simplest of actions; if I auto-attack the mob, will I hit? Or won't I?
The whole thing is complicated even more by the differences in PvE and PvP combat.
When you are fighting an enemy NPC, the stats of your target are determined by it's level. For every level, the mob has a full 5 Weapon skill and 5 Defense skill. You can use this known value to determine exactly how your Hit Rating and Defense skills will work against your NPC opponent.
When in PvP, however, your opponents are other players. And just as you are gearing up to increase your advantages, so are they. There is no magical number of Defense that will make you uncrittable in PvP; if that's your goal, you have to stack your Resilience as high as possible... and hope that your ability to stack your Defenses is better than your opponents' ability to stack +Crit. Or whatever those crazy face melters do.
Throughout this article, I will be talking about Hit Rating, Expertise and Defense skill, and how you can calculate exactly how much you need when facing a level 73 raid boss in PvE. I will also touch briefly on Resilience, and how it can modify your needed Defense skill.
Hit Rating and Expertise
First, let's talk about how Hit Rating and Expertise affect combat.
Your Hit Rating determines your chance to miss your opponent with an attack. If you increase your Hit Rating, what you are doing is decreasing your chance to miss.
Your Expertise skill reduces the chance for your attacks to be Parried or Dodged. The higher your Expertise, the less of a chance the enemy has to successfully Parry or Dodge your attacks.
In both Cat and Bear forms, you want to reduce the chance that your attacks will result in misses, Parries or Dodges. Not just for white damage attacks, but for your yellow 'special' attacks as well.
In Cat form, your role is providing massive DPS. You position yourself behind your target, so that he cannot Parry or Block your attacks. This leaves misses and Dodges as your biggest obstacles to providing melee DPS. With sufficient Hit Rating and Expertise, you could effectively reduce the chance that the target can avoid all of your attacks to zero.
In Bear form, your role is to keep your enemy occupied solely on you. In order to accomplish this, your physical attacks and taunts have to hit home. Hit Rating reduces the chance that your Growl or physical attacks will miss, and Expertise reduces the chance that your attacks will be Parried or Dodged.
As a further consideration, some enemies, on a successful Parry, hasten the speed of their next swing by 40%. Reducing your chance to have your attacks Parried lessens your risk of suffering more frequent burst damage.
This makes acquiring Hit Rating and Expertise very important to both Feral roles in a raid.
Your chance to miss is determined by comparing your own Weapon Skill against the Defense skill of your enemy.
An NPC enemy always has the full 5 Defense skill per level. At level 70, an enemy has 350 Defense skill. At level 73, the level at which all current raid bosses are set, the NPC Defense skill is 365.
As a Druid, when you are in a Cat, Bear or Dire Bear form, you automatically have the full 5 Weapon skill per level. Your claws are your weapons, and do not have their own Weapon skill to level; you are given the max 5 points as soon as you ding.
This means that at level 70, you are putting your 350 Weapon skill against either a level 70 mobs' 350 Defense skill, or a level 73 raid bosses' 365 Defense skill.
There are two different formulas for each of these situations, because once an enemies' Defense skill is more than 10 points higher than your Weapon skill, they get much harder to hit.
Against a level 70 opponent, or an enemy whose Defense skill is within 10 points or less of your Weapon skill, the formula for determining your base chance to miss is:
5% + (Defense Skill - Weapon Skill)*0.1%
Against an opponent whose Defense skill is more than 10 points above your Weapon skill, there is a different formula used:
7% + (Defense Skill - Weapon Skill - 10)*0.4%
That's all fine, but it's too much math. Let's break it down a bit.
From these formulas, you can see that when you are fighting an opponent the same level as you, you have a flat 5% chance to miss.
If your opponent is level 71 or 72, your chance to miss goes up .5% each time, to 5.5% and 6% respectively.
But against a level 73 raid boss, your base chance to miss jumps to 9%!
This is where Hit Rating comes into focus.
For every 15.77 points in Hit Rating you have, you reduce your chance to miss by 1%. This does not round up, so in order to reduce your chance to miss a level 73 raid boss from 9% to 0%, you need to equip 142 Hit Rating.
And 0% Miss is as low as you can get. After 142 Hit Rating, you are no longer receiving any benefit from the stat at all.
At level 70, for every 1 point you have in Expertise, your attacks have 0.25% less chance to be Parried and 0.25% less chance to be Dodged. Four points of Expertise gets you 1%.
For every 3.94 points of Expertise Rating you have equipped on your gear, you gain 1 point in Expertise.
So it takes 15.77 equipped Expertise Rating to reduce the chance your attacks will be Parried or Dodged by 1%.
I really hate these walls of numbers.
To determine how much Expertise Rating it is important for you to have, you should know that it's generally accepted that level 73 raid bosses have a base 5.6% chance to Dodge your attacks.
Therefore, with an equipped Expertise Rating of 90.62 (effectively, 91), you can achieve 5.75% reduced chance to be Parried or Dodged, and remove the enemies' ability to Dodge from the table entirely.
Equipment with Expertise Rating on it is fairly scarce at this time. Hopefully, the Wrath of the Lich King expansion will bring more items at the upper end with Expertise to balance out it's availability against Hit Rating.
Until then, however, I advise you to hold on to any items you get with Expertise, in case you find you need them in the future. You may find yourself at a point where the rest of your gear is outstanding, but you really wish you had that last little bit of Expertise to increase your chance to strike against a hard-hitting boss.
What Defense skill does is increase the chance you will be Missed, and the chance you will Dodge, Parry or Block an attack. I am not going to talk about this part of Defense skill in this article. For more information on the benefits of Defense skill, check out the Wowwiki article on Defense that goes into much more detail.
For Feral Druid tanks, the most important aspect of Defense skill is that it reduces the enemies' chance to Critically Hit you, depending on a comparison between your Defense skill and your opponents' Weapon skill.
The goal for us as Feral Druid tanks is to become immune to Critical Hits. And not just any Critical Hits, but those from level 73 opponents.
For every point of Defense skill you have above your enemies' Weapon skill, you reduce your chance to be Critically Hit by 0.04%.
Once your Defense skill matches your enemies' Weapon skill, then 25 Defense skill equals 1% of Critical Hit reduction.
As you can see from this, if all we are fighting is a level 70 mob, then our Defense skill already matches his Weapon skill. All we need to be immune from his Critical Hits is an extra 125 Defense skill to reduce the 5% Critical Hit chance to zero.
Or, we need something that provides 3% reduction in Critical Hit, and then another 50 Defense skill to make up the last 2% reduction. But more on that later.
Our chosen enemy to tank is a level 73 raid boss.
NPCs gain 5 Weapon skill per level, and have a 5% base chance to land a Critical Hit.
To counteract this, we need to reach 365 Defense skill to match the Weapon skill of a level 73 raid boss, and then we need enough extra Defense skill to reduce our enemies' chance to land a Critical Hit from 5% to zero.
The first weapon in our arsenal to accomplish our task is Survival of the Fittest, a Talent in the Feral tree. By placing 3 points in this Talent, we reduce the chance our enemies can land a Critical Hit on us by 3%.
Having 3/3 in Survival of the Fittest saves us from having to find 75 points in Defense skill. Our Warrior and Paladin tanking brethren have to stack that +75 Defense skill, just to match where we start out.
So we start out with 3% reduction in Critical Hits from our enemies. To make up the last 2%, we need 50 more Defense skill against level 70 enemies, and 65 more Defense skill against level 73 enemies.
65 Defense skill... plus the 350 Defense skill we start out with at level 70... brings us to 415 Defense skill for immunity to Critical Hits from level 73 enemies.
Unfortunately, we don't get Defense skill on our gear. We get Defense Rating instead.
I apologize for throwing that in there at you, but it can't be helped. Our gear has Defense Rating on it. And that's what makes this whole thing a pain in the butt.
For every 1 Defense Rating on your equipment, gems or enchants, you get 0.423 Defense skill.
Something to remember in this process, is you only get benefits from having whole numbers in Defense skill.
Having 2 Defense Rating for 0.846 Defense skill does not give you any benefits. But if you had 3 Defense Rating, you would have 1.269 Defense skill, and that would give you the 0.04% reduction.
Now, I know it's annoying to work with, but the 0.423 Defense skill per point of Defense Rating is important to know. When you are juggling enchants, gems and equipment stats, knowing exactly how much more Defense Rating you need to reach your goal is a big help.
So, is there an easier way to work with this number? Well, yes.
We know we need 65 more Defense skill to become immune to Critical Hits from level 73 raid bosses. Excellent.
If we divide and multiply and such, we find out that if we have 153 Defense Rating, we get 64.719 Defense skill. Only whole numbers count in Defense skill, so that doesn't quite get us there. No rounding up.
If we have 154 Defense Rating on our equipment, we get 65.142 Defense skill. That gets us to our goal.
Reaching 415 Defense skill is the basic foundation of becoming immune to Critical Hits.
I want to note here that the Elitist Jerks Feral Druid Megathread states that 154 Defense Rating is not good enough. In fact, they say that you require 156 Defense Rating to get to a true 415 Defense skill that the combat system will recognize, and accurately be immune to Critical Hits. If you are concerned about whether or not your gear is properly making you immune to Critical Hits, see the end of this article for a line of code you can run in the game to test your equipment.
There is one last piece to becoming Crit immune that I have to talk about, in order to be complete.
Resilience is a combat mechanic developed primarily for PvP combat, but it's effects have implications for our role as Feral Tanks.
Most PvP and Arena honor rewards are outstanding for filling in for a few pieces of tanking gear. The shoulders and the gloves in particular are very popular.
But when you look at those Arena armor pieces, you'll see that they don't have Defense Rating, they have Resilience.
Resilience has a lot of impact on Critical Hits.
At level 70, 39.4 points in Resilience Rating equals 1% Resilience.
1% Resilience makes you 1% less likely to suffer a Critical Hit, it reduces the damage you do take from Critical Hits by 2%, and it reduces the damage you suffer from all Damage over Time spells by 1%.
Yet another stat to deal with? It's a nightmare, is what it is.
Keep in mind that Resilience, while outstanding in PvP, is not so beneficial on a point-by-point basis when compared with Defense and Agility. It's great in the short term, no question, but you're not going to want to equip yourself with all Arena gear to tank effectively in PvE long term. But a couple of pieces can be a big help.
So what the heck does this Resilience mean for my tanking? How do I know what impact having the Resolute Cape (21 Resilience Rating) the Gladiators' Dragonhide Gloves (20 Resilience Rating) and the Gladiators' Dragonhide Spaulders (18 Resilience rating) will have on my immunity to Critical Hits?
Well, in the example above, you'd have 59 Resilience rating, plus 35 Resilience Rating from the 2 piece Arena Season 1 set bonus, for a total of 94 Resilience Rating. That works out to 2% Resilience and a bit at level 70, for a 2% reduction in chance to be Critically Hit.
And a bit? Yep, sorry.
But smarter folk than I have recognized the need to be able to determine whether or not your mix of Defense Rating and Resilience Rating gear is making you immune to Critical Hits.And they created a tool for you and me to use.
From the pages of Wowwiki is a line of code that you can copy/paste into a chat line in the game.
This line of code will add up your Resilience and Defense Ratings, and then compare them to your level to show you if you are immune or not. Just follow the process below to try it out.
Load up your character and equip the tanking gear you want to analyze. Doesn't matter if you're in Bear form or not.
Copy the following line of code using your method of choice. In Windows, it's typically Control-C.
Return to the game and open a chat line [/say].
Paste the line of code into the chat line (in Windows, typically Control-V) and hit return.
Your equipped gear will have the combined Resilience and Defense skill compared, and a numerical result will be displayed.
If the number displayed is 0 or negative, then you are immune to Critical Hits in your current gear. Congratulations.
If the number is positive, then you need more Defense skill or Resilience.
Personally, I have the line of code saved as a macro, so that if I'm playing with new gear choices I can hit a button and find out if I'm still okay.
Again, using this tool is only really necessary if you are mixing and matching gear, or paranoid about knowing exactly that you are immune to Critical Hits.
I know that this has been a long and complicated article, but I think that all Feral Druids can benefit by knowing exactly how Hit Rating, Expertise, Defense Rating and Resilience benefits them, and how much to look for when evaluating gear.
Any mistakes found in the information presented in this article are solely my fault.
I hope you find this useful!