Since the earliest days of World of Warcraft, the protection paladin (also known colloquially as the tankadin -- or in some quarters, Why won't it just die already?) has stood out among the other classes bestowed with a tanking role. We've come a long way from being the joke tanks of vanilla or the guy with a shield and a puddle brought in to AoE murlocs in BC. Wrath was when we first really hit our stride as top-tier tanks, and we've only grown more potent since the changes brought about by the Cataclysm.
The tankadin advantage
For one, our survivability is unmatched thanks to our amazing self-healing capabilities (some might go so far as to use the adjective "overpowered," but that's just crazy talk). Keep in mind I'm dating myself a bit, because our self-healing is slated to be nerfed in 4.1, though that won't be as catastrophic as many are proclaiming. Also in the survivability category, our mastery when capped is monumental, providing a constant 40% physical damage reduction. Those two factors add up to a seriously hard-to-kill meat shield.
Outside of staying alive, you can't beat our AoE tanking toolset. Combining Hammer of the Righteous with the Inquisition buff makes for a holy juggernaut that will have your co-tanks stewing. I'd also be loathe to omit mention of our group buffs (the various hands, auras, and blessings), heals and cleanses you can occasionally toss out in critical moments, and perhaps the most potent raid cooldown in the game, Divine Guardian.
Thanks to the recent change that makes Crusader Strike and Hammer of the Righteous misses/avoids not generate charges of holy power, tankadins are overly sensitive to having low hit and expertise. In raids, you'll hardly notice the dearth since the Vengeance mechanic basically provides free threat. Yet in content where you're taking less damage (and thus can't stack Vengeance as reliably), you'll feel the pinch. Gearing can mitigate this to an extent, but it's a pain nonetheless.
Prot paladins are the only tanking class that can't apply attack speed-slowing/physical damage-reducing debuffs on multiple targets at once like, say, a warrior can with a shout or Thunderclap. The trade-off, though, is we don't have a separate ability in our rotation that applies said debuffs, and we don't need to watch the debuffs and maintain them -- they're always there as a result of our normal rotation, which in the end is a fair trade.
Lastly, we're the only tank without an ability to close a gap between us and a mob. This is partly made up for by several ranged attacks and taunts, but more often than not, you'll be finding yourself plodding over to an add at 115% runspeed while begging the Light to keep that healer alive and furiously attempting to build threat at ranged while some caster has (ever so helpfully) laid into the target at full force with all cooldowns engaged. (I swear, it's like a sixth sense for them.)
Which stats are important?
Our stats generally fall into two categories: survivability stats and threat stats. While the lines might blur a bit for some, the survivability stats are stamina, mastery/block, dodge, parry, armor, and (by osmosis) agility; the threat stats are strength, hit, and expertise.
Stamina is our most obvious survivability stat. It's what makes our health bar flush with numbers and what allows us to take the big hits while lesser classes get the privilege of tanking the floor. While not as prominent as it was in the past, stamina is still your best defense against magic attacks (which can't be blocked or avoided).
Mastery and block are technically the same thing. Our mastery gives us block chance, while block rating itself exists solely in one lone enchant as some kind of bizarre stat fossil. As I mentioned previously, capping mastery by achieving 102.4% avoidance + block + miss means you will never take an unblocked hit, outside of turning your back to a mob. And that means that any physical hit you take -- assuming Holy Shield is active -- is reduced by 40%.
Dodge and parry are essentially the same stat; both help you completely avoid damage, but a parry will also hasten your next melee attack. Both of these will be tossed at you in uneven quantities through your gear, and you want to make a point of balancing the two to minimize losing any of either from diminishing returns. Ideally, because you'll be getting more dodge than parry through buffs, you want to keep your parry about 1% higher than your dodge via reforging.
Armor was once the king of our survivability stats, to the point that some (your humble corresponent included) made it a goal to cap, so that any physical attacks a raid boss dealt were reduced in damage by 75%. This required truly astronomical armor sums that were only made obtainable via generous gobs of bonus armor on different last-tier pieces. Cataclysm has nerfed the potency of armor immensely (see: armor trinkets available this tier vs. the last) and made bonus armor a scarce commodity. You don't want to seek out armor at this juncture. It just isn't as good as it used to be.
Agility makes the list only barely, because through it we gain dodge (and some crit, but that's neither here nor there). We once also got armor from the stat, but no more. Just dodge.
Strength, while being our most plentiful threat stat, is also the weakest of the three. It also gives a bit of parry but not nearly enough to write home about. We get it in piles on our gear, since it is our other major primary stat. And that's really about all there is to say about strength.
Hit is our second best threat stat and (obviously) gives us a higher change to hit with our various attacks. Just about everything in our arsenal is governed by the melee hit table, which requires 8% hit to cap; a few ranged spells fall under the aegis of spell hit. Thankfully, the Touched by the Light passive gives us a free 8% spell hit, so once you cap your melee hit, you're effectively capping your spell hit.
Expertise is our best threat stat, at least until soft-capped. It also has a tinge of survivability to it, as by reducing our attacks being parried, it reduces a boss' ability to parry haste and thus deal additional damage (though, to be fair, it's uncertain if any bosses can parry haste at the moment, at least as far as my research has gathered). We're fortunate to gain 10 skill of this stat for free, thanks to a glyph.
The key to being a tank is versatility -- knowing which tools you need to bring out for each fight to maximize your effectiveness. This is especially true with your spec, which you will want to tailor to whatever is currently standing menacingly in front of you. Being touched in the head like I am, I run with two different prot specs, one focused toward survivability and one that focuses more on threat. The former is best for boss fights, while the latter is best for trash, heroics that you are comfortably geared for, or boss fights in which you're wrangling adds (think Maloriak, for example).
Make sure to always avoid Hallowed Ground. It's a weak threat talent -- among our weakest -- and coupled with the fact that Consecration is seldom used (we have better AoE tools available), you don't get much return on your talent points.
Divine Guardian is a must-have for all specs. Heroics, raids, PvP -- anything but solo play, really. The ability to shave 20% off the top of all the damage the raid is taking for a few seconds is critical. That little talent pays for itself in spades, and you'll definitely want to have it in your arsenal.
From the ret tree, you absolutely want to go for the big four there: Crusade, Improved Judgement, Rule of Law, and Pursuit of Justice. I know Eye for an Eye looks tempting, but its output isn't nearly as stellar as you'd expect. You'll get a lot more value from having a longer range on your Judgement, giving you another ranged attack for building threat from afar. Similarly, Pursuit of Justice is really important for us because (as aforementioned) we need to jog over to a mob before we can really, solidly lock it down. Making our job 15% faster is very helpful.
If you're only prot part time or like to maintain a different spec, then you can safely go with the survivability spec, but swap a point from Reckoning into Grand Crusader for additional utility.
What about glyphs?
Our big three prime glyphs are Glyph of Seal of Truth, Glyph of Shield of the Righteous, and Glyph of Hammer of the Righteous. You'll want to employ all three unless you're sporting a survivability-focused kit. In that case, swap out HotR's glyph for Glyph of Word of Glory.
For majors, you'll want to tailor your choices to your situation. For single-target fights, use Glyph of the Ascetic Crusader, Glyph of Focused Shield, and Glyph of Lay on Hands (or if it's a very heavy magic damage fight, swap out Ascetic Crusader for Glyph of Divine Protection). For trash/adds, you want to make use of Glyph of Holy Wrath, Glyph of Dazing Shield, and Glyph of Lay on Hands.
Our minor glyphs continue in the proud tradition of our minor glyphs from Wrath by continuing to be utterly uninspiring. Grab Glyph of Truth, Glyph of Insight, and Glyph of Blessing of Kings for in-combat rebuffing/seal swapping.
What seal should I use?
Seal of Truth, primarily. It's threat (plus free expertise from the glyph) and very helpful for holding mobs. In harder content, I've gotten into the habit of switching to Seal of Insight once I have an insurmountable threat lead from Vengeance, to make use of the extra survivability the self-healing gives.
What's my rotation?
It depends on the situation! For a pile of trash that you're tearing through, there's not much more to say than hit Hammer of the Righteous as often as possible along with Holy Wrath and Avenger's Shield (pray for Grand Crusader procs!). Hit Judgement for mana as well, because AoE is expensive. If you have an empty GCD and the mana to spare, then you can drop Consecration.
Single-target is a little more involved, having a pretty set rotation that's been lovingly dubbed "939." The foundation of the system is prioritizing your attacks so that you're hitting Crusader Strike on cooldown (the "3"), and then weaving in either Shield of the Righteous, Judgement, Avenger's Shield, or Holy Wrath (the "9"s), in that order. Shield of the Righteous is our hardest-hitting attack, and you will want to use it as soon as you've accumulated 3 holy power. Judgement gives us mana and procs Sacred Duty, which guarantees a Shield of the Righteous crit. Rounding out the pack, Avenger's Shield hits like a truck, and Holy Wrath is just a filler and the best option for an otherwise empty GCD.
Strap on that shield!
Next week, I'll start digging into gearing for raids and heroics and discuss the philosophies behind the various kits you can set up to optimize your effectiveness in each -- whether you're staring at boss crotch with 24 of your allies or valiantly attempting to keep yourself alive through sheer force of will (and some healthy WoGing) while a freshly dinged 85 healer pugger in greens is sweating bullets in the corner.
The Light and How to Swing It tries to help paladins cope with the dark times brought by Cataclysm. Check out our suggestions for protection paladin addons.