The chance for a Crushing Blow
The base chance you may suffer a Crushing Blow changes depending on just how much higher level the Mob is compared to you.
The formula is; 2% (fixed value) * amount of NPCs weapon skill higher than your defense, minus 15%.
So in the case of the classic level 70 tank vs. level 73 raid boss, the formula would be 2% * 15 - 15%. Or 30% - 15%, for a 15% final chance. That means 15% of the time, an attack by the Mob will be a Crushing Blow.
If you were a level 69 Feral Druid going into Karazhan as the off-tank, something which has been possible for a while now, what with the attunement requirement removed, then your formula would be 2% * 20 - 15%, for a total of 25%.
That's right, one level makes the difference between a 15% and a 25% chance of an attack being a Crushing Blow.
Still, 15% of the time is still a lot, when you want to smooth out the spike damage that your healers need to deal with.
So how do you become immune to the possibility of suffering a Crushing Blow?
Short answer; if you're a Druid, you don't.
We eat the pain. We eat it like candy. But you gotta be durable.
But let's cut to the heart of this "Table" business.
This infamous "Table" thing
The Melee Attack Table (Mob vs Player)
Miss (Base 5%)
When an enemy Mob attacks you, level 70 vs. level 70, then out of 100% of the dice roll, these are the possible outcomes of the attack, minus Crushing Blows. If the Mob was 3 levels or more higher than you, this shows where they would appear on the Table.
With a base 5% chance to be Missed, if you had a 95% chance to Dodge attacks, then anything below Dodge on that Table gets "pushed off". It can't be one of the potential results of the attack.
That's all "Pushing it off the Table" means.
So a 95% Dodge would mean that for that attack, it could not result in a Parry, Block, Critical Strike, Crushing Blow or Ordinary Hit.
There is a lot more to the math, for example if the Mob is a higher level than you, then you need a bit more Avoidance in every defensive category to achieve the same result. If you would like more info about it, make sure to check out WoWWiki for some excellent discussion.
The key to our discussion is to take a look at what this Table, and Crushing Blows, means to a Tank.
How do you push results off the Table
Every possible outcome adds its percentage chance to the ones above it. Once the outcome reaches 100% (or, actually, 102.4% when talking about Mobs 3 levels above you), then the possible outcomes below that point are pushed off.
Every class gets a base 5% chance to Miss. Some classes can increase this with Talents.
Every class can Dodge. Chance to Dodge can be increased through Talents, Defense skill and Agility.
Paladins and Warriors can both learn Parry. Druids tank with their face. Druids cannot Parry.
Paladins and Warriors can use Shields to Block. Druids do not get Shields. Druids cannot Block.
Welcome to tanking on the wild side.
What conclusion can you draw from this, my Feral friends?
Obviously, you now know exactly why you seek out Agility: to increase your Dodge, the one Avoidance stat that Druids can actively work to improve.
Further, you now know that unless you can increase your Dodge to 97.4%, there is no way you can push Crushing Blows completely off the bottom of the Table.
Yes, there are quite a few of our Feral brothers and sisters raiding the Sunwell that can do exactly that. But for most of us, it's not going to happen.
Well, if we can't push Crushing Blows off the Table like Paladins and Warriors, what can we do?
Avoidance, Mitigation and Survivability
Feral Druids are known for excelling at three things;
- High Health
- High Armor
- Removing the chance for Critical Strikes
While Paladins and Warriors can add Block and Parry to their Avoidance, and remove the possibility of suffering a Crushing Blow, Druids work hard to obtain very high health to take a severe beating, and push on, ever on, towards higher armor values to reduce the amount of actual damage taken when we do get pounded.
And unlike the others, we can use Survival of the Fittest and Defense skill to easily remove the chance of a Critical Strike completely from the Table.
Without Critical Strikes to worry about, we only have Crushing Blows and Ordinary Hits to prepare for.
We plan on surviving Crushing Blows by having a decent Avoidance through Dodge, a wonderful damage Mitigation through high Armor, and surviving the damage that gets through by having a whole lotta Health.
What has been the point of covering all this?
Basically, to recap the philosophy behind why we gear the way we do, so we can talk about the next step.
Because in Patch 3.0 and Wrath of the Lich King, it all goes out the window.
Changes to Crits and Crushing Blows in Wrath
All that stuff about Crushing Blows will soon be obsolete. Blizzard is removing Crushing Blows from the "Mob +3 levels" Table.
Instead of Crushing Blows at 15 weapon skill over your defense, it will be set at 20 weapon skill over your defense.
And raid bosses are going to continue being set at 3 levels over your max possible level.
As stated by Ghostcrawler, this is going to keep Crushing Blows as something much lower level characters will fear when facing vastly higher leveled opponents, but it will remove them from what raid groups will have to plan for.
What does this mean for us, as Feral Druids?
Our tanking class has, up until now, been built around the idea that we needed to be able to both attain a Defense Rating of 415 with 3/3 in Survival of the Fittest to remove Critical Strikes from the Table, and also to have such a high Survivability that we could eat Crushing Blows.
In Patch 3.0 and Wrath of the Lich King, many things are still in a state of flux, but three things have been constant;
Let's take a look at Critical Hits first
We know that we will still be facing raid bosses three levels above ours. That remains unchanged.
So we know that the raid bosses will still have a 5.6% chance to score a Critical Strike, same as now, 5% base plus 0.2% extra per level over you.
Survival of the Fittest with a value of 6% now eliminates the need for us to have any Defense Rating on our gear whatsoever.
It also, as a side effect you need to consider, removes a large portion of the extra Dodge that stacking Defense Rating once gave us. Don't discount that, you're going to think in terms of needing more Agility to reach the same levels of Dodge, even more than you might have been figuring.
What about Crushing Blows?
With the removal of Crushing Blows, a large part of the justification for our awesomely high Health and Armor damage mitigation has been removed.
We still want it, oh boy do we still want it, but in terms of where Blizzard is going with our tanking future, it means they can feel justified in itemizing Leather gear with less Health and Armor on it, let us share gear with Rogues, and use our Talents to modify how much it benefits us in tanking.
We still don't Parry. We still don't Block. We should continue to expect to have higher Dodge, Health and Armor than Paladins and Warriors to make up for it.
But without Crushing Blows to prepare for, we can expect that we won't be hitting quite the same heights as before.
Because we won't have to.
Only time will tell how much the new Talents, like Protector of the Pack and Survival Instincts, will work to improve our Survivability and Mitigation.
Right now, I really don't want to speculate on the actual specs and Talents, because things are changing a lot in every build we've seen. I feel it's much better to discuss what we know, rather than what might be.
But as long as Ghostcrawler is telling the truth when she says that they are still looking at improving Bear Tanking AOE Threat generation, I have to say that I feel optimistic about our future as tanks.
But I am really going to miss that awesome high Health and Armor.
For a little additional reading, assuming you aren't dead asleep, I wrote an article to go with this one, about Swing Timers, Crushing Blows and Expertise. If you're interested, why not check it out?