Tiers: The past, present, and future of dungeon and raid sets

Information

Tier gear is a concept that has been with WoW since the beginning. In Molten Core, the very first WoW raid, each class had a set of gear that looked good together, could only be equipped by that class and that was, supposedly, specially tuned to that class's stat requirements. Priests had Prophecy, Warriors had Might, and so forth. This was called tier 1.

Classic WoW had three official raid tiers: tier 1 came from Molten Core, tier 2 from (mostly) Blackwing Lair, and tier 3 from Naxxramas. T3 is notable for a few reasons:

It was obtained via multi-class tokens. The bosses would drop, say, the belt token for Priest, Mage, and Warlock. You'd then have to take the token, some mats dropped by Naxx trash, and some crafting mats to an NPC to get the gear. This was useful because the boss drops became more flexible: if your priests all had their belt already, you could give the token to a mage or a warlock; if it had just been a straight drop of the priest T3 belt, you'd have to disenchant it.
T1 and T2 filled eight slots, while T3 filled nine, adding a ring. However, the highest bonus was for eight pieces, so you could choose which piece you wanted to leave out and still get the set bonus. This is continued in BC with five-piece sets, but only two- and four-piece bonuses.
When Wrath of the Lich King goes live (or possibly when patch 3.0.2 does) you will no longer be able to acquire T3. Naxxramas is being moved from its current location up to Northrend, where it will become the entry-level raid for level 80. Those who already have T3 will get to keep it.

Of course, T1 wasn't the first tier available. There was a tier 0, also known as Dungeon Set 1, which was gotten in high-level dungeons like Stratholme and Scholomance. T0 was not class-restricted, which led to much drama with Shadow Priests taking pieces of Warlocks' Dreadmist and the like. Why would they do that? Well, at the time, item sets just didn't cater to so-called "off-specs." If you were a Priest, your set items would be for healing; if you were a Warrior, they'd be for tanking; and if you were a Druid, they'd be for healing again. It wasn't until Burning Crusade that the token system for tier gear was put in place, and an excellent move it was too.

There was also a Dungeon Set 2 in classic, also known as tier 0.5. It was obtained by upgrading your T0 pieces through questing. And that's not the only ".5"-numbered tier, either; there were generally sets that you could get through places like ZG and AQ that were labeled "tier 1.5" and "tier 2.5," but these labels always felt a bit forced to me. T0.5 makes more sense.

Moving on to BC, a few things changed, as I mentioned above.

All tier pieces are on multi-class tokens, and for the first time one token can be turned in for multiple different pieces of gear per class. For instance, Druids have three different tier 4 sets, one for each tree.
Tier sets are mostly five pieces, to allow for additional flexibility in gearing.

Before you get to the new tiers, of course, there's a new dungeon set, Dungeon Set 3. Like DS1/T0, these are not class-specific, though some of the set bonuses are. This so-called "tier 3.5" is gotten in the level 70 instances throughout Outland.

Tier 4 is obtained in Karazhan, Gruul's Lair, and Magtheridon's Lair. Tier 5 comes from Serpentshrine Cavern and Tempest Keep. And Tier 6 comes from Mount Hyjal and the Black Temple, with three more T6 items for each set added in the Sunwell Plateau (bringing back the eight-piece set). So much for BC.

What lies ahead in Wrath of the Lich King? Almost certainly more tier sets. Naxxramas, the first raid, has enough bosses to provide an entire tier there (as T3 was originally), so I'm going to hazard a guess that tier 7 will be acquired through multi-class tokens in Naxxramas. There will probably also be a Dungeon Set 4/tier 6.5, gotten in the level 80 instances.

However, raids in Wrath have an additional wrinkle: each will exist in a 10-man and a 25-man version. Blizzard have said that the 25-man drops will be "a full in item progression" above the 10-man ones from the same raids. If we take that literally, we come to the intriguing possibility that T7 might drop from the 10-man version of Naxx, and T8 from the 25-man version. Then when we move ahead to Ulduar, the second LK raid, we can get T8/T9 for the 10-/25-man versions.

I'm not sure that this is exactly how it will play out, though (note that we don't have any actual data on LK raid drops yet, so I'm guessing here). There are a couple snags in that scenario:

Typically, you need gear on the level of tier (x-1) to be able to down bosses that drop tier (x). If this held, it would mean guilds would have to do Naxx-10 to be able to move on to Naxx-25, which would be problematic.
If I did Naxx-25, Ulduar-10 would suddenly become pointless for me, at least in terms of set drops. Again, problematic.

But I'm not really sure what a better solution would be. Get rid of tier gear altogether? Caster pieces should be much more versatile now that spell power is in, so that is a potential solution. Or there could be two different versions of every tier, depending on whether it was gotten from 10- or 25-man raids, but that could get cumbersome. Naxx-10 could drop T7, Naxx-25 T7.5, Uld-10 T8, and Uld-25 T8.5 - in other words, narrow the gap between 10- and 25-mans. But then you run the risk of further irritating those who are already upset at what they see as 25-mans being deprecated.

In general, I don't understand how they're going to maintaing a tier of separation in drops between 10s and 25s, without requiring extra gear to start on 25s. It's a sticky situation, and I'm interested to see what they're going to do with it.