With the final battle against the Lich King just on the horizon, Lead Content Designer Cory Stockton and Lead Systems Designer Greg Street discuss what awaits players inside Icecrown Citadel and offer a glimpse at the design process behind Wrath of the Lich King's ultimate raid and dungeon encounters.

What were you looking forward to most about developing Icecrown Citadel?

Cory: I think the most exciting thing about developing Icecrown Citadel was just knowing that we were working on the final chapter of the Northrend expansion, and that we'd really be able to give players that ultimate sense of completion of the storyline. Arthas is a huge character in Warcraft lore, so we took a lot of pride in making this the best experience we possibly could.

Icecrown and the Frozen Throne are important parts of the world of Azeroth and have quite a bit of history, especially for longtime Warcraft players. How do you convey the significance of these places and the events that took place there in design?

Cory: History was a large factor in the design of Icecrown Citadel from the very beginning. When we first sat down to discuss the layout of the raid itself, we immediately went back to Warcraft III: The Frozen Throne to think about how the spire from the ending cinematic could be translated into World of Warcraft. We decided to actually build Icecrown Citadel around the original spire to pull players even more into the storyline. This kind of thinking carried on throughout the entire design process.

Greg We want Icecrown to be an epic experience from top to bottom, and that includes the loot you get. We're not going to shower players in items -- well, more than we already do -- but we do want to make sure the items are sufficiently powerful so that they're upgrades for all of our players.

Is there an existing model in World of Warcraft for Icecrown Citadel's itemization or style of play? What lessons that you'd learned from earlier projects wound up being applied to Icecrown Citadel?

Greg The nice thing about Icecrown Citadel from an itemization perspective is that we have lots of bosses. That's something of a relief coming from the Crusaders' Coliseum, where we had only five bosses. For Icecrown, we can afford to have multiple options for a particular slot -- say a healing leather bracer or a melee trinket -- and even itemize some of the more unusual pieces. We have a pretty effective system for figuring out who is going to drop what to make sure that an individual boss will be interesting to a variety of players in terms of loot. Most of our lessons learned are in the realm of what differences there should be between 10- and 25-player itemization, the role of tradeskill recipes, and what kinds of items to place with badge vendors.

Cory: I think we learn lessons from every raid that we do. We didn't model Icecrown specifically after any of our previous raids, but you can definitely see influences. For example, we have a winged structure in Icecrown that players will remember from Naxxramas. Another example of an influence would be the teleporters from Ulduar. We know that players really loved that concept, so we brought it back in Icecrown.

Can you talk a little about how artists and designers on the team collaborated on the creation of Icecrown Citadel?

Cory: The design and art teams worked extremely closely throughout the entire development process. The biggest single influence on the look and the layout of the dungeon comes from our concept art, and there was no shortage of that for Icecrown Citadel. Once we locked down the layout, we were able to get to work on the final art extremely quickly thanks to the existing style we'd developed for the Icecrown zone. We really wanted the players to feel connected to the environment, but we wanted to make sure it still had an amazing look. Often times, these two things are hard to mix, but in this case, I think we've been able to pull off an amazing dungeon from both the art and design standpoint.

What sorts of new loot and item abilities will we see in Icecrown?

Greg There are three main sources of loot for Icecrown: the bosses themselves, the Emblem of Frost badge vendors, and a new faction, the Ashen Verdict, that will provide suitable rewards as well, particularly at the Exalted level.

As far as the items themselves go, we want them to feel epic. In addition to having favorable optimization, we also want to try a lot of experiments to make the items feel cool and unique. We are going to try to do a lot of weapon procs, for instance, which is something we haven't done much since the original World of Warcraft.

When you set out to itemize "sister" areas -- like the Icecrown Citadel dungeon and raid, or Halls of Stone, Halls of Lightning, and Ulduar -- do you take any steps to make loot from these places feel similar?

Greg Absolutely. We approach that on two fronts: the art and the names. When we did the Halls of Stone and Lightning, we hadn't completed the Ulduar raid yet, so the items there didn't necessarily have Titan-influenced art models for us to use. We are doing the Icecrown dungeon at the same time as the raid, and it's a style we already know pretty well, from Naxxramas and even the Warcraft RTS games.

Naming is something we've had a lot of fun with. There's a ton of lore to draw from for Icecrown loot and it has a very strong "kit." World of Warcraft players know to associate the Scourge with spiders, bats, and cultists along with more traditional forms of undead, like skeletons and liches.

Do you itemize Icecrown's "trash" -- the enemies between bosses -- differently from elites elsewhere in the world?

Greg We make sure there is epic trash loot -- specific items that only drop from trash. It helps keep players interested between bosses. However, we aren't doing Heroic trash, just Heroic bosses, so there won't be unique trash loot for Heroic versions of the 10- and 25-player versions of the raid. We try to construct the trash in such a way that it isn't trivial to go farm the first pull or whatever in hopes that an epic drops. We make our raids more accessible now in general, so I'm not sure the motivation is there to try stunts like that the way it once was. We want players who have raided so far in Wrath of the Lich King to be able to actually fight the Lich King, so chances are a lot of raiders will have plenty of opportunities to gear up. Now, the Heroics are another story -- those will be as challenging as they were in Ulduar and Trial of the Crusader, and the items will likewise be even better.

What have you done to make the tier-10 sets feel like a meaningful advancement from tier 8 and tier 9? How do they visually represent Icecrown's lore and history?

Greg Not only do we want them to be a meaningful advancement, but we want them to feel really awesome. This is Arthas loot you're talking about. We started by spending a lot of time on the concept art to make sure it tied into the type of creatures you'll encounter and the whole Icecrown art "kit" in general. For example, the rogue tier-10 set has a strong geist look to it, while the hunter set has strong Nerubian elements, and the mage set looks a lot like the Blood Princes. You can see the Icecrown look and feel in a lot of pieces, which itself drew strongly from the Lich King's original helmet. Look for lots of blue, ice, skulls, and spikes.

We have also spent a lot longer on the set bonuses than we usually do. It's important that they feel awesome for every class and spec. Going back to the Crusaders' Coliseum, part of the challenge we made for ourselves was to create an instance that didn't require as much time or resources as Ulduar to develop, yet was still cool. We had set bonuses for the tier-9 gear, but they were often simple -- more crit on a common ability was a typical one. For tier 10, we're really going for set bonuses that change your game up a little. At the very least, you should want to change your rotation a little, though this is easier with some classes than others.

If you had something like a mission statement or a slogan for itemizing Icecrown, what would it be?

Greg Epic. Cool things. Proc'y stuff.

Seriously, that's our mission statement. One of the risks of itemization is making things feel too formulaic. We know that when we step outside the bounds too much, players can have a bad reaction to it, like, "Why does my gear for this tier suck?" It's easy to fall into the trap of making the new gear feel just like the last gear with 20 more stat points. That is the exact design approach we use for the PvP gear, and left unchecked, it would be easy to go the same direction with the PvE gear as well. We're trying not to do that. We think we owe it to Icecrown for the gear to be memorable, but that means we're going to take a few chances.

Can you talk about any of the new mechanics we'll see in the raid?

Cory: One of the coolest new things we're doing in Icecrown is the gunship air battle. Players will be able to board their respective faction's gunship and then take to the air for a battle to the top of the citadel. They'll be fighting on the decks as well as using vehicles' cannon emplacements. If you're really daring, you can put on a goblin rocket pack and propel yourself back and forth between the two battling gunships. Needless to say, this will be a type of encounter that our players have never experienced before.

Icecrown Citadel's structure is extremely vertical -- what challenges does that present from a layout perspective?

Cory: Well, we knew from the start that the layout was going to be vertical, just due to the nature of the original spire. There are a number of things that we're doing to help players get around and not get lost. We're using elevators, teleporters, and even gunships to get players where they need to go in the dungeon. We are also going to have an in-game map with full support for all floors -- that should help too.

Icecrown is the last major raid and dungeon before the release of Cataclysm -- how has that affected the design?

Greg The major challenge from an itemization perspective is that the items have to last basically until Cataclysm. That means we can't afford to give them away too quickly, but they also need to feel powerful enough that players are motivated to keep trying for them. On the other hand, the really fun thing about doing a final raid tier is how it unties your hands. We can afford to make these items great because nothing needs to follow on their heels. It's cool to be able to optimize the items very well, because it's okay if players don't want to replace these items for a long time.

Cory: We are really pushing as hard as we can to deliver the most epic experience possible. We know that our players have been waiting for this for a long time, and we plan to deliver. Everyone should expect to see this sort of storytelling and attention to detail in Cataclysm as well. I think we are always striving to pull the people who play our game into the storyline and really give them an explanation for why they're there. It won't be too long before they'll get a chance to bring the pain to Deathwing!

Thanks, both of you - we're looking forward to playing through Icecrown Citadel after patch 3.3 is released!