Firefight

"Drop feet first into a new way to play Halo with the cooperative campaign mode, Firefight."

- Bungie Firefight is a single or cooperative campaign mode for Halo 3: ODST where up to four players can participate with one another via System Link or Xbox LIVE and combat against the Covenant. According to Bungie's Halo 3: ODST project page, the mode allows four teammates to "battle in multiple environments, on foot or in vehicles, and against increasingly difficult waves of Covenant attackers."

Firefight will have no limit on the waves of enemies and will continue until the squad has completely run out of lives, however there are five waves in a Round and three rounds in a Set. The Set, Round, and Wave the player is in can be seen at the top left of the screen, with the number of players lives. The Set number is represented by a number from one to infinity, the Round will be represented by a circle, going from left to right with the wave the player is in shown under the Round. At the end of the round there will be a brief pause where the player will be allowed to recollect ammo, and get additional lives. The scores will be kept in the top right of the screen, with the Team score being on the top and the player's individual score below that. It is also confirmed that the player's helmets will be removable.

Regardless of the difficulty, the Tough Luck skull will be enabled from the start. With each new set, more skulls become enabled, more than one at a time. If you can stay alive, they will be awarded with higher scores and heaps of medals. Though each enemy class is worth a base number of points, earning medals can modify the player's tally as they go. Staying on lengthy streak without dying, and points will be augmented by a hefty multiplier.

Additionally, once a team has survived a Set, they will go on to the Bonus Round. Because it is only a Bonus Round, any deaths will not be subtracted from the overall point pool. However, since the Iron Skull is activated at the start, one death will cause the Bonus Round to end. The Bonus Round provides players a chance to earn extra lives before the next Set. It has also been mentioned by Bungie that the Round will consist entirely out of Grunts.

Xbox users who pre-order the game will be able to play as Sergeant Johnson in this mode.

Players are allowed to customize their armor, emblem, background and Service Tag much like in Halo 3 multiplayer.

Maps
Maps are as follows (List unconfirmed):


 * Alpha Site
 * Chasm Ten
 * Crater
 * Last Exit
 * Lost Platoon
 * Rally Point
 * Security Zone
 * Windward

Characters

 * Rookie: Unlocked by default.
 * Dare: Complete the Campaign on Legendary.
 * Buck: Unlock the Tayari Plaza Achievement.
 * Dutch: Unlock the Uplift Reserve Achievement.
 * Romeo: Unlock the NMPD HQ Achievement.
 * Mickey: Unlock the Kizingo Boulevard Achievement.
 * Sgt. Johnson: Comes with Pre-order of Halo 3: ODST.

Trivia

 * Firefight might play out like Survival Mode from the Marathon games, Horde from Gears of War 2, Nazi Zombies from Call of Duty: World at War, and Survival Mode from Left 4 Dead in that they all have you try to survive and beat countless number of enemies over a long period of time.
 * The player will be able to choose from four skulls at the start: Blind, Cowbell, the Grunt Birthday Skull, and IWHBYD; their effects are the same as in Halo 3. The skulls can be seen at the left side of the screen, the ones active will be highlighted.
 * According to the Bungie Day (7/7/09) Podcast, the last man standing will be able to revive his/her entire team by earning three Hero Medal. How to acquire these hero medals is currently unknown.
 * According to firefight video clips, some of the enemies may come from Phantoms, while on Firefight map "Crater", some may come from "Monster Closets".
 * There are 7 characters to choose from Firefight. (If you include Sergeant Johnson)