Avalanche

Avalanche is a multiplayer map featured in Halo 3. It will be featured as one of the three maps in the Legendary Map Pack available on April 15th, 2008.

Setting
Avalanche is a huge Forerunner power station set on the front of a huge glacial shelf on the reborn Installation 04. The structure pulls its power out of the densely compacted ice that constantly builds up behind the station before it falls into the ocean below.

Design
Avalanche is a re-imagination of Sidewinder, a map in Halo: Combat Evolved, removing certain design elements, such as the tunnel in between the two bases, while adding new ones, such as the many Man Cannons. New Forge objects have been created just for this map and can seriously change gameplay. These objects include shield doors to block entrances and exits, large sniper perches that will stay in place if put in the air, and Forerunner ramps and such like that can be used to make an entirely new base if you are creative enough. The map itself is centered around two bases at each end of a U-shaped snowy valley, and to add an interesting dynamic, there is an asymmetry in the vehicles — in objective gametypes one base has exclusively UNSC vehicles to begin, while another has exclusively Covenant vehicles to begin. The map is set to prefer objective gametypes. It is also the largest map in the Halo franchise ever.

Gameplay Features and Changes

 * The hallway between the 2 bases has been removed. This includes the gate where the Overshield and Active Camouflage spawned.
 * A few Man Cannons and a large cavern area have been added to the original 'Sidewinder'.
 * In the Legendary Map Pack Darkness trailer as seen here it shows that the Forerunner architecture on the side perform as a man cannon. This has been confirmed with the April 10th ViDoc.
 * In one-sided objective gametypes, the attacking team has UNSC Vehicles, while the defenders have Covenant and Loyalist vehicles.
 * All UNSC vehicles will now feature snow camouflage colors instead of the traditional green UNSC color scheme.
 * The Scorpion Tank is only available to the assaulting team on one-sided objective based games; during team slayer, neutral and multi objective games both sides will have the Wraith Tank.
 * A bottomless pit is located in the center infantry area of the map. This pit can be crossed by the man cannons there. They are located in the middle of the canyon, opposite to the bases.
 * Energy doors can now be placed in Forge to cover up Exits.

Vehicular Balance
As seen in a recent overview of the map which was released by Bungie, one-sided objective games will have a Human vs. Covenant vehicular setup, while symmetrical game-types will have all UNSC vehicles (presumably). Here are the lists of the vehicle sets to be included:

Asymmetric game-types:

Defenders - Wraith, Ghost, 2 Choppers, Banshee.

Attackers - Scorpion, 2 Mongoose, 2 Warthogs, Hornet (A Downgraded variant).

Symmetric game-types:

Both teams have a Wraith Tank, Mongoose, 2 Warthogs and a Hornet.

Forge
In the Bungie.net Weekly Update on 4/4/08, it was revealed that there will be many new and unique Forge items for Avalanche. These are mostly Forerunner-themed, to keep with the style of the map. A few of these items are:


 * Forerunner-style walls
 * Energy-Blockers (Shield doors that cannot be walked through).
 * A sniper perch, which is in one picture turned upside-down, thus being able to hold a Scorpion tank.

Trivia

 * During production, Avalanche's code-name was "Cottonball."
 * It is the first multiplayer map to see the Hornet get downgraded. The missiles were removed, and the chainguns do less damage, to balance out the map. As such, the vehicle will be included in Matchmaking for the first time ever, and it is also the first map to include the Scorpion tank as a default vehicle.
 * Avalanche is the first and only Halo 3 map to feature teleporters by default.
 * Avalanche is the first multiplayer map in which the vehicles get an appearance makeover in the Halo franchise.
 * The map is set on the Installation 04 (II) and resembles the last level of Halo 3, Halo, although the campaign level has no trees like the new map.
 * A structure in the background is identical to the shield towers on The Covenant.
 * The map was actually rebuilt from the original Sidewinder map, and includes the same overall shape, a mid-section joining the bases, and near-parallel bases separated by rock.
 * Avalanche is the only current Halo 3 level that features a Hornet, though not as powerful as usual, by default. It is also the only map that features a Scorpion by default, though only in One-Sided Objective gametypes and only for the defenders.
 * Avalanche contains the most vehicles of any Halo 3 multiplayer level, even more than the number on Sandtrap.
 * It is still unknown if it is possible to place regular colored UNSC vehicles on Avalanche, but you probably won't be able to to keep with the snow theme.