There are many types of equipment available in Halo 3. Some of the equipment is used for defense, while others are for dealing damage to Covenant troops. Teams are scattered throughout the missions.
Bubble Shield when dropped will generate a dome-shaped force field around the player. You can protect anyone inside the Bubble Shield by preventing shots from penetrating the shield. However, anyone, including enemies, can go through it. Grenades, except Spike Grenades, simply bounce off the shield. The shield will vanish after about 30 seconds or when it takes a large amount of damage. The shield can be deactivated immediately by destroying the device. You can use the Bubble Shield when you suddenly find yourself under fierce gunfire.
The portable gravity lift when activated will generate a force field, which will propel anyone who steps on it upwards. It is ideal for reaching high perches or climbing walls. You can use the Gravity Lift to jump to higher ground and escape a chasing Chieftain. You need it to jump to a high platform to get the Cowbell Skull in The Ark mission.
Another useful piece of equipment is the cloaking device. With this device, you can remain invisible for about twelve seconds. It’s great when facing enemies with weapons on a narrow walkway or trying to get out of a tight spot. Better to walk away quickly after activating the cloaking device. He can still melee and throw grenades without being visible, but firing his weapons will affect his visibility.
The invincibility device is another piece of equipment for getting out of tough situations. Once activated, you will be impervious for ten seconds to all forms of attack, including a hit from a Gravity Hammer. However, falling from a great height will still kill you.