So, you've purchased Wrath of the Lich King, you've created your Death Knight, and you've finally completed the trek to level eighty. Now what? Well, lying before you, you have a choice : DPS or tank?
This article is for those of you that chose tank.
Tanking as a Death Knight is unlike playing any other tank class in the game, so even if you have tanked before, it can be somewhat disorienting. Death Knight tanking can be even more odd to a first-timer, who is expecting a different sort of experience, something in line with a Warrior.
The first thing you must do to tank, even before worrying about your gear, is select the right talents. Contrary to popular belief, there is no "tank tree" for Death Knights. Death Knights, given the right combination of equipment, can tank f Aion any tree. Rather than giving you a simple template to replicate in game, I've chosen instead to outline some of the more effective tanking talents by style. There are so many Death Knight builds out there that even amongst the established builds, there is no "tank build". More than any other class, Death Knights encourage ingenuity and individuality when spending your talent points. Once you've read over the guide, then you can go about the business of selecting the talents best-suited for you.
THE MUST HAVES
There are three tanking talents, all of which are entry-level talents, that form the foundation of Death Knight tanking - Blade Barrier, Toughness, and Anticipation. Every tank build that you create should feature all three of these talents. Blade Barrier and Anticipation in particular are extremely potent and boost the primary function of Death Knight tanking : avoidance.
SELF HEALING - BLOOD TANKING
Blood tanks gain access to self-healing in the form of five different talents : Rune Tap, Improved Rune Tap, Mark of Blood, Vampiric Blood, and Bloodworms. Blood's self healing makes it strong for single target encounters.
Each of the three trees has a "utility" cooldown for tanking; Vampiric Blood is that cooldown for the Blood tree. With it, the potency of ALL heals, not just your own, are improved for twenty seconds.
Rune Tap should really only be considered in conjunction with Improved Rune Tap and is best used early and often; don't "save" your Rune Tap.
Mark of Blood is good for all bosses, but especially good for fast hitting bosses.
Unfortunately, you can't really control when the Bloodworms appear, but they heal for a sizeable amount, especially if you happen to have Vampiric Blood up at the time. Some tanks may wait for Bloodworms to appear before hitting their Vampiric Blood, but often the encounter itself will dictate when you need to be using your cooldowns. As a side note, Blood Aura probably doesn't heal enough to justify you spending talent points in it. Your mileage may vary, especially after patch 3.0.8.
VERSATILITY - FROST TANKING
To some, Frost is the Death Knight tanking tree; as we've established, though, there is no such animal. Frost does, however, have a lot of great tanking talents, including an extra utility cool down (one more than the other two trees), and versatility. While not quite as strong at AE tanking as Unholy Death Knights, Frost Death Knights can AE tank effectively. While some would argue that Blood may be better for single-target tanking, especially short duration tanking, Frost holds its own here as well.
Frost's two cooldowns are Lichborne and Unbreakable Armor, the latter of which can be glyphed to make it even more effective for tanking. Lichborne is one of the better tanking cooldowns in the game, Death Knight or no, and its mid-tier position in the Frost tree makes it a good candidate for Blood or Unholy tanks with Frost secondaries. F Aion personal experience, Lichborne combined with Icebound Fortitude allowed me to tank Patchwerk by myself, after our main tank died, while Patchwerk was both enraged and frenzied. I really don't think a non-Death Knight could have done it.
Frost tanks can select f Aion a large pool of passive tanking talents : Frigid Dreadplate, Frost Aura, Acclimation, and Guile of Gorefiend. Frigid Dreadplate strengthens the core Death Knight mechanic, avoidance, while Frost Aura and Acclimation make Frost shine as a spell tank. Guile of Gorefiend increases the duration of a Death Knight's bread and butter, Icebound Fortitude.
Finally, Frost tanks specialize in augmenting their tanking with Frost damage and effects, whether it be speed reduction f Aion Improved Icy Touch or generating AE threat with the damage f Aion Howling Blast.
MULTIPLE TARGETS - UNHOLY TANKING
Unholy is the talent tree for those that want to be able to generate threat and keep aggro on more than one mob at once. It shines in heroics or any raid where multiple mob tanking is required.
The main component to Unholy's AE threat generation is Morbidity, which drastically decreases the cooldown on Death and Decay. For the record, Morbidity also makes Unholy a very good tree for holding threat against single targets as well - Death and Decay needn't be only used for groups of enemies.
Talents like Outbreak and Impurity increase the damage of Pestilence and Blood Boil, the two abilities used after Death and Decay to generate AE threat. Crypt Fever and Ebon Plague are both good for maintaining threat on enemies you've already diseased. Corpse Explosion can be a fun little extra toy to whip out now and again in large groups. Some would argue that Unholy Blight is the best 51 point Death Knight talent for tanking, as it adds another layer to AE threat generation for Unholy tanks. Depending on how fast the pulls are coming, you can usually get this ability off not long after the beginning of a fight. No maintenance bursts of AE damage is a no brainer for AE tanking. Bone Shield is Unholy's utility cooldown. While primarily a DPS talent, Bone Shield will help you avoid up to four blows, calculated after your own innate avoidance. It should be up before all multiple target pulls and refreshed as often as possible for bosses.
And finally, while Unholy's main strength is AE tanking, it also makes a great magic tanking tree, with Anti-Magic Zone.
PICK AND CHOOSE - HYBRID TANKING
It is possible to build a very effective tanking talent spec by pairing mid-tier talents f Aion two talent trees. All three of the talent trees combine well with one another, although you're obviously going to lose some potency in the primary function of your talent trees if you spread out your talent points between two trees.
Now that you have a good grasp on what some of the primary tanking talents are, you have a base on which you can start plotting out your talents. Remember, there are loads of talents in all three trees that are going to be good for tanking. Tanking isn't just about mitigating damage, for the Death Knight, it's also about dealing damage, as that's the best way to generate threat. While your damage abilities are less than those of other Death Knights that are focusing on damage dealing talents, once you've got your tanking bases covered, you should be looking at things like Annihilation, Scourge/Frost/Heart Strike, or the expertise talents.
After you've got your talents in order, you can experiment with tactics for tanking specific bosses, disease rotations, and really hone your skills.
