The Lead Developer for World of Warcraft, Ghostcrawler, has been posting quite a bit recently concerning the Block Mechanic. Block is a core part of how Paladins and Warriors tank.
A lot of the tank balance problems we are having exist because we thought block would be a better mitigation stat than it has turned out to be. I say "we" because the druids and DKs were also convinced at the time that they would be mana-sponges and everyone was quoting "The unblocked hit is the new crushing blow."
For a variety of reasons, reality didn't work out that way. For one, we underestimated how much removing crushing blows would change the landscape. In fact, you can argue that the big magic hits (the dragon breaths and plasma blasts) are really the new crushing blows, and block does nothing to them (modulo 4 piece bonuses and the like). DKs were given amazing cooldowns, high armor and high avoidance to make up for them not being able to block. Druids were given even higher armor and high health. We backed druids off from that a little in part because they were going to end up with dps stats almost no matter what gear they chose so we wanted to incorporate those a little more into tanking. We kept buffing DKs based on early (mostly heroic dungeon) reports that healers hated healing DKs because they were so squishy when their cooldowns were blown. That seems to be less of an issue now with current levels of gear and some of the other changes to the game since then.
We will almost certainly change block. I can't tell you when we'll change it, because it's a big change. We probably don't want shield-users to be at 100% up time of block if they block more per hit. We have to be careful what happens to threat since that's a big part of block, especially for warriors. Heck, maybe we fall in love with the 4 piece warrior bonus and decide to make that a core part of the ability.
We are less likely to just buff the shield-using tanks because we like the current difficulty of the hardmode fights for them and we are reluctant to have to buff those encounters to correspond for a tank buff. Though as we've said elsewhere, we might give paladins another cooldown. Just remember that one player's "slight advantage" is another's "faceroll tanking and trivializing encounters." The balance goal has always been "close enough" not "identical." (source)
Think about it this way.
Avoidance is good because it removes a lot of damage. Avoidance is bad because it is unpredictable. If you stack too much avoidance, you are likely to give your healers coronaries.
Mitigation (armor and straight damage reduction) is good because it's consistent. As you all point out, you can start to learn how much a blow will actually do to you. Mitigation is bad, from a player's perspective, because it can't save you. If you have 10 health and dodge, you might live. If you have 10 health and hope your armor will save you... well, it won't. You become the dreaded mana sponge because you are never avoiding damage completely.
Mitigation also has a risk from a design-perspective that when fights get too predictable they become too easy and unexciting. Imagine a tank with 75% damage reduction and no avoidance. You could calculate from the moment of the first attack whether you will survive the encounter. Heck, you might be able to not even heal the tank and know you'll survive depending on the specific abilities used by the boss.
Block as a mechanic is somewhere between avoidance and mitigation. Ideally it removes a fair amount of damage (vs. all damage) reasonably often (vs. rarely). If block is up 100% of the time it just becomes armor that you improve through a different stat. We have let block chances creep up frankly because the amount blocked is pretty trivial when bosses are hitting for 40% of your health pool every swing. If this still strikes you as too RNG, imagine abilities like Shield Block and Holy Shield that could guarantee 100% chance to block for a short period of time.
We don't think block is cutting it as a mechanic, but the direction we are likely to take it is probably more of a change than you are considering.We also don't think it's necessary that every tank rely on avoidance, block and mitigation in equal amounts. They can't get too far apart or someone will come to dominate for certain encounters, but we don't think the tanks need to be completely homogenized to get what we want either.If (to make up numbers) the DK and druid get hit for 20K every swing that hits, but the warrior and paladin get hit for 24K half the time and 16K half the time, then that seems like it would work. When the boss emoted that his big hit was coming, you could make sure you had your cooldown ready to guarantee a block. (source)
We were starting to see many guilds ask their warrior or paladin to step aside so the DK could tank the hard mode encounters. This was not an isolated incident for a few guilds -- this was the kind of widespread phenomenon that really makes us take notice. If it was a boss or two that the DK was the best at, we would have just kept an eye on it. Increasingly though it was every hard mode. I will be the first to admit that the community is wrong sometimes. We don't think that is the case this time. The numbers backed up their conclusions pretty well.
If we can get block to be a powerful mitigation stat again we realize that will change the landscape and we'll have to evaluate the staying power of all 4 classes again. For now, we hope this change will put the tanks in a much closer place. (Though if you are keeping note, we would still like to give paladins another reliable cooldown.)
Lead Systems Designer
Block is a core part of how Paladins and Warriors tank. The way Block works is that Block removes a fixed amount of physical damage equal to the tank’s block value when the tank Blocks.
It’s fairly obvious a change is coming to Block.
The issues with Block are that it’s a static amount of damage reduction, it only works against Physical Damage and it’s split between two stats, Block Rating (chance to block) and Block Value (how much you block). One of the main misconceptions people have about block is that you take no damage from a Blocked hit, and that isn’t true. Trash in Ulduar can hit for 15k, but if you block the hit, that hit will only land for about 13k. Healers barely notice. This is why you’ll see very little Block Value gear on my Paladin. I have the Tier 8 Shoulders in my Armory, but I use the Tier 7.5 for Bosses. My Bracers have Block Value, because those are the only epic Tanking bracers I’ve seen drop and won.
I tend to gear for Armor, Stamina, Dodge, and Parry because Block just doesn’t provide much benefit in the current Tier.
Block’s true strength is against fast, small attacks like you see when AoEing trash or some Dual Wield Bosses. Of course we haven’t seen a Dual Wield Boss in Tier 7 or 8.
The real killer in today’s tanking world is the huge magical hits against which Block does nothing.
So what will happen?
I think we can expect the ‘Block Cap’ to be unreachable, and we’ll see Holy Shield changed to be a 100% block chance like the Warriors Shield Block skill, with similar uptime (20 second duration with a 1 minute cooldown). It becomes a ‘sort of’ cooldown. This makes Paladins and Warriors even more similar than they are today. It will be especially interesting what the new Paladin cooldown is, and how it will differentiate from the Warrior cooldowns.
It’s also interesting that he mentions the Warriors 4 piece set bonus. This bonus is 20% damage reduction from magic damage while Shield Block is up. Perhaps what they are considering is having Block Value work against magic or having some set magic reduction anytime you block, I’m not sure. We may or may not see some sort of magic damage reduction added to Block.
What concerns me most is the comment he made that a Druid/DK would get hit for 20k every time while a Paladin/Warrior would get hit for 16k half the time and 24k half the time. I don’t play a healer, but I have a pretty good idea which type of tank they’d rather heal. As the only tank that could reliably Block Cap, Paladins have been touting their steady damage intake all of Wrath.
My concern is that for the scenario GC outlined doesn’t really work. Sure, it averages out to the same damage over time, but it’s when those big hits land that’s key. If the Shield Tanks are designed in such a way that you could get two back to back 24k hits (to use GC’s numbers), then they must have the Hit Point pool to survive that, or they aren’t really tanks. Talk about giving Healers coronaries? That will do it. You’ve got to give the healers enough time to get you healed up.
To really work, Paladins/Warriors must have the Hit Point pool to survive two back to back 24k hits (to use GC’s numbers),or we’ll be paper tanks. But if we have the Hit Point to take two back to back hits we might be OP compared to DKs/Druids.
Tanking balance is a finer line to walk for the developers than DPS or Healing. Tanks have to be chosen and assigned. DPS does not. A DPS class that wants to prove itself simply goes out and dominates the meters. You also have less Tank spots open in a raid than any other role. Some bosses only require a single Tank. Who that is going to be is a call Raid Leaders have to make. They are going to put the best tank on the job. The rest of the Tanks, don’t get to play their primary role on that encounter. That’s just how it is.
I’m no fan of homogenized classes, but when it comes to Tank balance, it certainly is better than the alternative.
I’ve got a ton of Block gear in the bank, maybe I’ll actually need it soon. Who knows.
We’ll wait and see what they come up with, but for the first time in Wrath, I’m just a little apprehensive about my future.
Thinktank did a fantastic post on this issue as well. Now that you've read my thoughts, go check it out. http://wowthinktank.blogspot.com/2009/05/general-future-of-block-part-1.html