Armor Ability

Armor Abilities are exclusive gameplay enhancements featured in Halo: Reach. It is a refined version of Halo 3's Equipment feature, where instead of being used once, each ability will be reusable, with a cooldown time between uses. These can be accessed through each "Weapon Set" before a match is starting or during your respawn time.

Sprint
Sprint allows the player to lower their weapon and move at an increased speed for a certain length of time. Even though the player lowers their weapon, it has been confirmed that he or she will still be able to use grenades while sprinting. This ability will only be available for the Spartans.

Evade
The Evade ability allows the player to roll in any direction to avoid danger, breaking enemy lock-ons and tracking in the process. This ability will only be available for the Sangheili.

Active Camo
The Active Camo provides players the ability to have Active Camouflage for a period of time, similar to Thel 'Vadam's active camo from Halo 2. The Camo will deplete faster if you run, so crouching and slowly walking will deplete the Camo slower. Also, when the player moves faster, the Camo will not entirely camouflage the player, but when moving slowly or immobile, the Camo will cover the player completely. It also serves as a Radar Jammer. However, this not only jams other player's radars but your own as well.

Jet Pack
The Jet Pack ability allows players to maneuver in mid-air, with the use of a jetpack. The ability varies with the button presses. If the button is held without releasing, it will deplete continuously, but the player can also use it in bursts which deplete it less than a sustained flight. It will be useful for evading splatters, grenades, and navigating maps.

Armor Lock
The Armor Lock ability provides the player a small shield which protects the user from any harm, acting similar to Halo 3's Invincibility, and sends out an EMP blast to nearby enemies, pushing them away from the player before emerging. Any Plasma Grenades sticking to the user will be de-stuck.

This ability also varies with how long the button is pressed: the longer the button is held, the farther the final blast radius will be. This ability not only works against other players, but also at incoming vehicles, as seen in the Multiplayer Beta trailer.

Trivia

 * Armor Abilities function similarly to the Arbiter's Active Camouflage from Halo 2 and the flashlight in Halo: Combat Evolved.