Cut Halo 2 equipment

During the game's development, Halo 2 was planned to ship with many more equipment items which ultimately did not make it to final release. For the most part they were never prototyped in engine and only ever existed in paper design documentation penned by multiplayer lead Max Hoberman. As such, the only equipment that made it to final release were Active camouflage and Overshield.

Adrenaline
Referenced only in documents for the cut map Cyclone, the Adrenaline powerup was to spawn on the map at "position B". Little is known of the Adrenaline equipment's function, though it was speculated by Hoberman to have been intended to be a speed boost similar to the Haste power-up mentioned below.

Haste
"There will be a new power-up called Haste. This will increase your movement speed by 250%, when you move at full speed you will have motion blur."

- Haste's description in the Halo 2 design documentation.

Haste was a power-up functionally intended to cover the same niche as the speed boost later introduced in Halo 4. The power-up was present in 2003-era design documentation, though ultimately never saw any kind of implementation.

Infravision
"When you use this power-up, you'll be able to pick out opponents better in dark environments and far away. You will also be able to see invisible players - if an explosion goes off while you're using this power-up, you'll be temporarily blinded."

- Infravision's description in the Halo 2 design documentation.

Infravision was to serve as an augmented vision mode, similar to the VISR mode in Halo 3: ODST or the Promethean Vision ability in Halo 4. Like Haste, the mode existed on paper-only, and was never realised. Infravision was ultimately cut due to the lack of dynamic lighting present in the game to make the power-up workable, alongside other aforementioned issues.

Quad damage
The quad damage power-up is only mentioned offhand in a design document from November 2003 referencing a now-cut gametype known as The Light Bringer. In The Light Bringer, the player holding the quad damage powerup (referred to as "the quad" in the text) would deal increased damage to enemy players and regenerate 10HP for every kill they dealt. A damage boost powerup was later introduced in Halo 4.

Health pack
In earlier revisions of Halo 2, the game had useable health kits similar to its predecessor in Halo: Combat Evolved. The feature was cut over time, as the evolving balance of the game saw player health become less and less relevant, until the decision was made to remove it from the UI entirely.