Power-up

"Power-ups" give you an advantage over the other players in a multiplayer battle in Halo: Combat Evolved, Halo 2 and Halo 3. On a few occasions, they're also found in Campaign, only in Halo: Combat Evolved's though. You activate them as you walk into them, unlike Equipment which is not activated instantly, can be held for use later and can be exchanged with other Equipment tools.

Trivia

 * The Custom Powerup's default settings increase your speed and melee power. It has been speculated this was to be the effects of a unused Agility Powerup.