Covenant shield generator

The Shield Generator is a structure utilized by the Covenant in Halo Wars, which provides shield protection for the whole Citadel.

Summary
The shield technology used by the Shield generator is repurposed Forerunner technology and requires vast amounts of power to use. Once the shield is drained, the buildings underneath the shield begin to take structural damage. Over time, the shield will begin to regenerate back up to full strength.

Expensive, and taking up a build slot, commanders who wish to use the Shield generator must choose between a strong defense and other options. It is powerful enough to withstand a direct hit from the UNSC Spirit of Fire's Magnetic Accelerator Cannon. Better to get it either early or after you have quite a strong army.

If multiple shield generators are built onto one Citadel, the shields become much stronger. It is a good idea to place the shield generator to the rear of your base, in order to protect it from enemy fire once the shields are down.