Of course this is hardly news for experienced tanks. But if you've never been much for tanking and are curious about giving it a try, or your guild is short on tanks and needs your DPS loving self to strap on the sword and board for a while to get Gruul down, or if you're just plain new to the class then this may be useful for you. Or maybe you'd rather I sang the theme to The French Connection. It's my birthday, I could do that. But instead I'm going to write more about tanking and then go eat some cake.
Before we get going I should take the time to point you to this thread on the Elitist Jerk forums. Mine it for its juicy nuggets of useful goodness.
First off, of course, we'll talk about defense. To break it down in the most simple manner I can manage, defense mitigates damage by increasing the chance for you to be missed, for you to block, dodge and parry, and by reducing the chance a mob can critically hit you. It also lowers the chance that a mob will hit you with a crushing blow. Against boss mobs that are always effectively three levels higher than you, this is important. However, it's important to note that raw defense by itself cannot prevent crushing blows, it can merely reduce their frequency. A level 73 mob will always have a chance to hit you with a crushing blow because the maximum defense that you can apply vs. their chance to crush you is your own level multiplied by five, even if you have far more defense than that. This is why you will need more than just defense, you will need other forms of avoidance like additional block, dodge and parry as well as abilities such as Shield Block to help push your combined chance to dodge, block or parry an attack up high enough that the boss' chance to crush you gets reduced. We generally call this 'pushing the crush off of the attack table.' Since a blocked attack cannot be a crushing blow, by increasing your combined chance to be missed, to block, parry, and dodge you can cause the crushing blows to, in effect, not be possible.
The magic number most warriors shoot for in tanking is 490 defense. (Note: not defense rating, but actual defense skill.) This is 140 points over your normal level 70 maximum, and almost completely removes critical hits, although even at 500 defense I've been crit occasionally. You can argue back and forth as to whether or not I'm wrong, I can only report that I believe no amount of defense can entirely remove critical hits but that at 490 defense or better, they will be extremely rare, to almost nonexistent. (The other day in Heroic Botanica I believe I was critically hit once, but without checking the combat log I may be misremembering. At any rate, one crit is a dang sight better than lots and lots of crits, I'm sure we'd have to agree.) For a new tank coming up, try and get to 490 defense as your first priority, and only once you find yourself at that level of defense start worrying about weighing other stats against defense. As your gear gets better, you will find yourself actually choosing armor and items based on other stats, as the increased defense on better gear will allow you to stay at 490 defense without making as many sacrifices.
Once that happens, each warrior will tell you a different strategy for staying upright in fights. I personally have two sets of tanking gear right now, although several pieces overlap. I have what I call my 'stack shield block' set, which has several pieces that push my shield block up for when I'm tanking physical mobs and I want to try and make sure I take as little incoming damage as possible, and I have my stamina kit for when I'm taking mobs that do heavily magic-based damage or otherwise require me to have as much health as possible.
Next let's talk about armor. In the past I've been critical of armor for warriors, because frankly I find it irritating how much you hear 'but you can wear plate' when discussing other aspects of the warrior class. Armor is very valuable for tanking multi-mob physical damage pulls, or for mitigating the damage that comes in from a boss mob who does a lot of physical damage. The Elitist Jerks threat uses as an example the idea that Archimonde hits for 30,000 damage before armor is factored in. Think about that for a moment. Against a clothie with, say, 20% damage mitigation Archimonde hits for 24,000 damage. Not even a warlock can survive that. Now, high armor druid, paladin and warrior tanks (the druid will always have more armor, but the other aspects of a warrior or paladin tank can help equalize this) can reduce this damage to the point where it becomes survivable for a tank. For instance, reducing that incoming damage by, say, 75% would mean that Archimond hits you for 7500 damage - a very large hit, yes, but at the point where you have near 75% damage mitiagtion by armor, you'll also have significantly more health than that. While 75% mitigation is more or less the 'armor cap', it would take roughly 35k armor to get that, so don't spend a lot of time worrying about it for when you're starting out trying to tank your first heroic. You're simply not going to have that much armor, but then again, hopefully nothing in a heroic is hitting you as hard as Archimonde. After you get your defense to 490, I would give as much weight to higher armor as I would to higher stamina. The one - two punch of having more health and more reliable damage reduction helps make a healer's life less hectic as your life bar doesn't dance up and down like some kind of frantic skittering insect or the polygraph machine at a Liar's Club function.
It is my suggestion, and other warriors feel differently and will argue most compellingly for their beliefs, that you place your priority as follows as you gear for heroics: defense, then armor/stamina, then dodge, parry and block. I am not arguing that the pure avoidance of gear that boosts your chance to dodge, parry or block isn't good, merely that defense provides a boost to all three at once while each of those provides a boost only to its associated stat. A cloak with dodge rating on it will help you mitigate damage, and it may well work out to be mathematically better than a cloak with defense rating if the dodge rating is high enough, but the defense cloak will add to your dodge, your parries, your blocks and even to your chance to be missed. Once you've achieved the near-crit immunity of 490 defense and have stacked your stamina and armor, though, pure avoidance on gear is certainly welcome and some warriors have dodge or parry 'sets' for fights where they feel stacking those stats is a more effective tanking strategy. The point, however, is that no matter how you do it, avoiding damage is a good thing. While you want to take some damage in order to generate rage, you want to control the flow of damage you take to minimize how hard your healer has to work to keep you up. Big, spiky crits and huge crushing blows are the real enemy here, not the average hits that do miminal damage and serve mainly to keep your rage bar in the red while the healer uses a few downranked heals to maintain you near full in preparation for the moments where big heals are needed. It's the healer's job to keep you up, yes, but it's your job to make that as painless as possible for her or him. After all, they have to watch not just you, but the entire party. You make this easier by generating threat so that they don't have to work as hard healing anyone else, and by maximizing your mitigation so that they don't have to work as hard healing you.
A good healer/tank team, working together, can become an awesome thing to behold. On my human warrior I recently tanked a heroic Slabs run where, at the end, no one in the party had died or even gotten below half health at any time, I tanked at least two mobs on every single pull (we only had a rogue and hunter for CC) and sometimes up to four without the healer even noticeably straining to keep me up. This leads me to discussing tanking abilities you should keep in mind and become accustomed to using.
The first is disarm. Against mobs who use weapons, disarm is a beautiful thing. It generates threat and reduces how much damage they can do to you. On some boss fights, if you have another warrior handy you can keep disarm up for almost the whole fight. (This makes the Romulo and Julianne fight a bit easier.) It's a situational ability, but you want to get in the habit of trying when you see a weapon so that you develop a feel for when to use it and when not to. As a tank, you should be plenty familiar with using Shield Block already, since it's one of the ways you'll be pushing crushing blows off of the table, but if you're not then get familiar with it. Revenge is still one of the best ways to generate threat, you should be using Shield Block to set that up. Also, if you've just specced protection for tanking, put Last Stand somewhere where you will remember you have it. If you're about to drop and your healer is frantically trying to get that big heal you desperately need off on you, make it possible by giving yourself 30% of your max health back. 30% of 10,000 health is 3000, which can nicely pad out the danger zone if you got a big chain of hits and the healers are struggling. Make sure you tell them you used it, so they don't let you pop back down to 1 health when it's over, that's embarrassing for everyone. Another ability to consider for a mitigation role is Concussion Blow. A mob that can't hit you can't hurt you. Improved Revenge is also useful in this manner, although far less reliable. I do tend to save Conc Blow for aggro loss moments myself, as I generally love the chance to bash something over the head and make it stand still long enough for a big Shield Slam to get threat back to where I like it, so you'll have to learn to judge for yourself when you use this ability for mitigation. Also work on your spell interrupts like Shield Bash and Spell Reflection. If they don't get to cast a spell or, even better, have to eat their own spell, it's more damage you don't take. Spell Reflection takes some work to master... I'm still improving myself... but the best part about using it is, you get threat from the damage you reflect multiplied by your own defensive stance and defiance abilities. So it's a handy chunk of threat and mitigation in one neat package. I just wish it lasted longer.
This is all very basic, of course. We could spend entire columns on just one of these topics. (And we probably will.) And I'm sure that the experienced tanks out there will take me to task for not presenting sufficient detail on how defense and the attack table work (someday I'll do an entire table on how to push crushes off of it, I promise), the merits of pure avoidance vs. defense, armor caps and stacking stamina, etc etc. Sadly, we only have so much room per column.
Next week I expect we'll talk about easy to obtain tanking gear. I've covered chestplates before, so next time I may focus on rings, trinkets and capes as those can often be the most frustrating slots to fill. If you're looking for a specific piece, though, feel free to ask about it in the comments.