Blizzard has been busy the past couple of days posting noteworthy updates to the World of Warcraft site. In addition to today's sneak peek at the Arena season 8 armor sets, Blizzard also revealed today that players will have the chance to obtain the Lich King's warhorse, the Invincible Charger, by defeating him on Heroic difficulty. We can only assume at this point that the mount will be a pretty rare drop.

In addition, Blizzard posted an interesting article yesterday that gives some background on how the World of Warcraft team designed the gunship battle in Icecrown Citadel. You can read the whole thing after the jump.

The frozen earth of Icecrown roils with throngs of the undead Scourge, reanimated bodies so numerous that there are few physical locations where the Horde and the Alliance can build their camps and strongholds. Instead, the defenders of Azeroth take to the sky.

Two gunships, the Skybreaker of the Alliance and Orgrim's Hammer, named for the former Warchief of the Horde, patrol the skies of Icecrown. Early in the campaign against the Lich King, these grand vessels were used to scout overland terrain, where they frequently came into open conflict with each other, brightening the skies with their cannon fire.

Now, in the wake of the Argent Tournament, the enemies of the Scourge have finally gathered to lay siege to Icecrown Citadel. With the fortress nearly impenetrable on land and the spires of the citadel touching the sky at their peaks, it's become clear to the leaders of both the Horde and the Alliance that an aerial assault, spearheaded by these two gunships, is the only way to infiltrate Arthas's stronghold.

Two prominent warriors have stepped forward to lead the attack: Muradin Bronzebeard of the Alliance and High Overlord Saurfang of the Horde. Both seek to defeat the Lich King and spare the living from another plague -- but there are other, more personal stakes for these heroes. Saurfang seeks to uncover the fate of his son, whose body was lost at the battle of the Wrath Gate, while Muradin, bearing the weight of Arthas's atrocities, seeks justice, closure, and possibly even redemption for his former student.

And yet, even with their noble goals, there will be no shared glory for the Alliance and the Horde in this attack. The dock atop Icecrown Citadel is only big enough for one ship. Halfway up the spires, the Skybreaker and Orgrim's Hammer are fated to clash again in a storm of gunfire, swinging blades, and bellowing warriors. Foremost in this mayhem are the combat crews, veteran heroes who've already begun the assault on Icecrown and who will fight to the last for a chance at Arthas -- heroes like you.

In this article, the World of Warcraft development team discusses the inception and construction of one of Icecrown Citadel's most frantic and epic raid encounters. Take your eyes off the sky -- just for a moment -- and read on.

Creating the gunship battle in Icecrown Citadel was a unique and exciting challenge for the World of Warcraft team. For quite some time, we've heard requests from players who wished to see ship-to-ship combat realized in the game. Since Icecrown Glacier doesn't have much in the way of flowing water, we opted to use the gunships, which were already a major fixture of the Icecrown zone, to bring that idea to life. In the battle, players take on the role of the combat crew for their faction's ship: either the Skybreaker on the Alliance side, helmed by Muradin Bronzebeard, or Orgrim's Hammer on the Horde side, helmed by High Overlord Saurfang. With their own weapons, the ships' guns, and a strong, coordinated plan of attack, raiders struggle to knock the enemy faction's gunship out of the sky and ascend to the peak of Icecrown Citadel.

When we began work on the gunship battle, we knew that we wanted the idea of "controlled chaos" to be central to every second of the fight between the Skybreaker and Orgrim's Hammer. Rather than making the encounter a traditional single-target "wear down" or "tank 'n' spank" battle, we took steps to make sure that the heroes who serve as their ship's combat crew would be constantly engaged -- moving, fighting, and dealing with a high volume of visual and spatial inputs.

Our design discussion started with a talk about victory conditions. We planned a straightforward main objective: to win the fight, the enemy gunship must be defeated before it takes down the players' gunship. Beyond this straightforward objective, we made it a point to include ongoing mini-objectives in order to keep the pace of the fight continually frantic.

"Defeating" a gunship with spells and swords alone wasn't something we felt would be appropriate for a high-flying, bombastic encounter like this one, so we decided that damage to both gunships would come from an ongoing exchange of cannon fire, and players would man the deck-mounted cannons of their gunship to try and take down the enemy. We supplemented the ship-to-ship exchange by including enemy artillery to blast back at the players -- riflemen or axe throwers would attempt to take down the players with their ranged weapons, while heavier artillery would launch rockets and mortars at the gunship.

Though we wanted the battle to look and feel furious, there was a danger that our continued artillery barrage would cause the screen to become cluttered with arcing shells. To combat this, we made our cannon shells, rockets, and mortars telegraph where they were likely to land with an "impact icon." This would encourage dodging and allow detonations to be deliberately avoided, adding another layer of frenzied movement to the encounter...and that's even before the cannons get shut down.

Rather than force some players to only manage their cannons throughout the entire battle, we opted to keep players moving by temporarily deactivating the cannons' ability to deal damage to the enemy ship. After the hull of the enemy ship takes severe damage, an enemy mage encases players' cannons in a block of ice. In order to defrost their cannons and stay in the fight, players must defeat the mage...who stands protected dozens of feet away on the deck of the enemy gunship. This interruption in players' damage provided us with one of our most exciting opportunities to keep building "controlled chaos" into the fight.

From our earliest discussions, we wanted to make sure that a way of boarding enemy ships, a classic element of ship-to-ship combat in pirate and fantasy fiction, made its way into the final gunship encounter. Swinging across ropes or using a grappling hook on an airship as it spiraled upwards through the sky seemed likely to send every member of the combat crew falling to their doom -- but we needed a means for players to move between the ships in order to let them pursue the enemy mage and make the fight feel cinematic.

To emphasize the danger and chaos of the encounter, we ultimately decided that participants in the battle would use goblin rocket packs to travel back and forth between the gunships. Goblin craftsmanship is notorious for being unreliable, and sending first-time rocketeers careening between ships with thousands of feet of open sky beneath them was our way of ratcheting up the tension and keeping the battlefield constantly shifting. The packs can also be used for offensive positioning. When a member of the crew lands from a rocket jump, the rocket pack deals damage and provides a slowing debuff to nearby enemies.

We knew that players would use their rocket packs to reach the enemy mage on the deck of the opposing gunship, but we wanted to put a few additional obstacles in their path. First is the enemy leader -- Muradin or Saurfang -- a dangerous melee powerhouse. Each leader defends the deck of his ship when players rocket over and must be held at bay while the players simultaneously face off against the enemy mage and combat crew.

The enemy crew themselves provide the second major obstacle: they continue to assault the players' gunship while their own is boarded. Their ongoing attacks provide them with combat experience, which increases their strength and the damage they do to the players' gunship the longer they are ignored. If the players' deck is left insufficiently defended in the assault, enemy forces will hurl burning pitch that does significant damage to the hull and can even set the deck ablaze. Lastly, the enemy's forces are replenished from below deck, resulting in a continuous surge of foes that must be held off even as the players race to unfreeze their cannons and continue their offensive.

The battle rages on until one ship sinks below the horizon.

We're excited we were able to bring the gunship battle to life in patch 3.3, and we hope players enjoy it. It continues Wrath of the Lich King's tradition of epic dungeon brawls while providing a new, different, and exciting challenge on the path to Arthas. Grit your teeth, keep your footing, and watch the air catch fire. We'll see you in the skies over Icecrown.