Cloaking

Were you looking for Active Camouflage, used in Halo: Combat Evolved and Halo 2?

Cloaking is a form of equipment in Halo 3. It can be found on many levels in Campaign, but it is not present in Multiplayer. Once activated, it has the same basic function as Active Camouflage from the first two games: it renders the user nearly invisible.

One notable difference between Cloaking and Active Camouflage is that Cloaking is a piece of equipment -- it can be activated whenever the player chooses to, whereas Active Camouflage is automatically activated when the player collects it. In addition to being more portable, cloaking is also more effective in Halo 3 than Halo: Combat Evolved's Active Camouflage -- while in Halo: Combat Evolved, you could see the entire body faintly, in Halo 3, only a faint shimmer can be noticed. There is a disadvantage to Cloaking, however -- it only lasts for ten seconds, after which its effect fades over the course of an additional two seconds.

Like Activate Camouflage, firing a weapon, performing a melee, tossing a grenade or coming under fire slowly begins to disrupt the effects of invisibility and brings the user into sight. Cloaking also does not mask environmental effects or any shadows cast by the user, so it is less effective on maps where footprints can be left or where shadows can easily be seen.

The symbol for the Cloaking on the HUD resembles the Active Camouflage power-up from the first two games - a triangle with an eye in the middle. Enemies will not notice you while you are camouflaged as long as you do not do anything to disrupt it, as noted above, or bump into them. If you activate it in plain sight during a battle, enemies will still know your location. It should be noted that Brute Chieftains can occasionally sense your location, turning slowly as you move and attacking if you get within a few feet.

Trivia

 * Cloaking is first seen in Halo 3's second Campaign level, Crow's Nest. Cloaking appears most frequently on the the Halo 3 Campaign level Cortana. It can be quite helpful on Heroic, Legendary, and Mythic.
 * It resembles the Invincibility item, but glows blue instead of gold.
 * The Cloaking HUD icon resembles the top of the pyramid seen on the reverse of the Great Seal of the United States. The seal can be found on United States Federal Reserve Notes.
 * While cloaking is activated you can't pick up any equipment until the effect has worn off.
 * The Cloaking icon resembles the all-seeing eye pyramid/triangle.