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 Loadout before a match is starting or during your respawn time. All Armor Abilities are rendered useless to players when transporting objects such as Flags and Skulls. If players attempt to use an Ability, the object simply drops out of their hands.

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 depletes 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 enemy radars but the player's one as well. Allies will not be affected. When the player uses the Camo, all sound is heavily muffled, so it is not easy to notice a grenade or an opponent shooting.

Armor Lock
Armor Lock is an ability that 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 Grenade sticking to the user is removed upon activation. There are two versions of this power, one for Elites and one for Spartans.

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.

Evade
Evade is a Sangheili-exclusive ability that allows the player to roll in any direction to avoid danger, breaking enemy lock-ons and tracking in the process. You can evade two times before having to recharge.

Jet Pack
The Jet Pack ability allows players (regardless of their multiplayer biped) to maneuver in mid-air, with the use of Jet Pack propulsion equipment (UNSC) or an Antigravity Pack (Covenant). The ability varies with how long the button pressed. 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 is useful for evading vehicles, grenades, and navigating maps.

The Jet Pack ability is rendered useless to players when transporting objects such as Flags and Skulls. If players attempt to use it, the object simply drops out of their hands. Fall damage still applies to Jet Pack users should they fall from the air.

Sprint
Sprint is a Spartan-exclusive ability that allows the player to lower their weapon and move at an increased speed for a certain length of time. The player can still throw grenades while sprinting.

Trivia

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