Deployable cover

Overview
Deployable cover is new piece of Covenant Equipment in Halo 3. It was officially confirmed that this new piece of equipment was going to be in Halo 3 in the September 2007 issue of Electronic Gaming Monthly, among other online forums and magazines.

This shield is similar to the Stationary Shield Generator of the same type seen in Halo: Combat Evolved and Halo 2, except it can now be deployed anywhere. Additionally, the player (or AI character) is able to fire through the shield from behind it with projectile weapons, but any bullets and other solid projectiles coming from the front will be deflected. Plasma fire is stopped by the shield from either side. This gives the player an enormous tactical advantage in exchange for being exposed from behind and to the left and right, whereas the Bubble Shield provides complete 360 degree cover, but cannot be fired into or out of.

The shield is deployed in the same manner as all other equipment in the game, and it will stay activated until it takes enough damage. The shield's health is represented by its color: it is normally blue, turns red as it is damaged, and finally deactivates. If left alone, the shield will regenerate to full health. To deactivate the shield permanently, the base must be destroyed.