Equipment

... In Halo 3, Spartans, Elites, and Brutes can carry one extra item of equipment – deployed using the “X” button (default setting) on the Xbox 360 controller. Equipment types vary dramatically in purpose, functionality and appearance, but all can be used with deadly or strategic force. To follow is a simple explanation of what each does, and where you can find at least one of them. There may be more to find and their availability is subject to matchmaking rules.

The philosophy of equipment is simple: add variety to the combat in Halo 3 without displacing balance. The simple fact is that Equipment items, once deployed can be used by both attackers and defenders. Someone on your team might accidentally activate your Trip Mine, and a Bubble Shield is a geometric spherical shield – sure they can’t shoot in, but you can’t shoot out either. A good tactic involving the bubble shield is to run in, throw a grenade, and run out again, instantly killing all in there. Suffice to say that equipment can turn the tide of battle if used correctly. To make it more balanced, it takes longer to deploy equipment than in the Halo 3 Beta, but you can launch it farther. It is not entirely clear which faction - Human or Covenant - manufactures each piece of equipment in the first place without doing research on the specific equipment, as both are seen utilizing it in the single player Campaign.

List of equipment

 * Bubble Shield
 * Power Drain
 * Radar Jammer
 * Grav Lift
 * Trip Mine
 * Flare
 * Regenerator
 * Deployable Cover
 * Automated Turret (Campaign Only)
 * Cloaking (Campaign Only)
 * Invincibility (Campaign Only)

Trivia

 * Though many of these are available in Multiplayer, the Automated Turret and Invincibility are exclusive to the Campaign for balancing reasons.
 * In the January 2008 issue of EGM, in an interview with Brian Jarrard and Tyson Green, it was revealed that there was a piece of equipment cut from the final game known as The Vortex. It was said to be deployed the same as a Power Drain, but would instead create a mini black hole that would "suck in any object within range, and diverting its course into the black hole, and away from your face." It was even able to affect nearby objects such as the Fusion Coil and even other players. The design was cut due to the fact that it was too "expensive" from a networking and performance standpoint.
 * The Trip Mine may be the famed Lotus Anti Tank Mine from the Halo novels, despite the fact that it has 2 spokes less than what is mentioned and that it cannot destroy a Scorpion Tank that has not been previously damaged.  Although in Assault the bomb does say Lotus Anti Tank Mine,  it may be a weaker variant.
 * When you try to drop a piece of equipment on a vehicle or object (like a crate), the equipment will go through the object and end up underneath it. This happens to prevent players from driving around in vehicles with bubble shields and/or other equipment mounted on them.
 * Drivers of vehicles cannot use equipment (with the exception on the Invincibility and Cloaking); however, passengers can, which can be useful.
 * With Active Camoflauge on in front of a Auto-aim Turret, it can still detect you.
 * In campaign the Deployable Cover lasts indefinitely until it is destroyed, but in multiplayer it only lasts for about one minute.