The Shield Generator is a defensive building which projects a shield over a large area, protecting any buildings within from damage. This protection includes fire from any regular military unit, long-range missiles, Nuclear, and Laboratory, accidents, as well as damage from tornadoes and fires, even if the shield generator is activated only after the fire started. The shield will absorb any fire damage in place of the protected burning structure. If the fire is not extinguished however, it will eventually tear the shield down and proceed to burn the structure beneath. Because the shield is so strong, it is able to withstand the Bombing Run of a Firebird. Protecting, lets say 10 Flaks in your main city with just one shield generator simply means your enemy won't stand a chance against the Flaks, unless he sends 2 Firebirds and does 2 Bombing runs, or sends a Nuclear missile. The shield is therefore possibly the most effective defence structure in the basic game, if it wasn't for its high power upkeep when its active, and the fact that you need at least 1200 Eco Executives to unlock it.
Every building within the generator's influence area will receive an independent shield with 5000 hitpoints and a regeneration rate of 100. This regeneration rate is fast, but only active when not under attack.
Shields from multiple generators can stack.
The generator itself is not protected by its shields, but can benefit from other generators.
Shields are immediately removed from all buildings when the generator is deactivated or destroyed. Since the damage of a long-range missile is applied over several seconds, one generator alone will provide no protection against a well placed nuke. But it can without any problems protect buildings against the Missile that are fired by the Orca and Erebos, even though all roads affected by the missiles will be destroyed, which could actually be looked upon as a glitch, as roads are meant to be indestructable, just like the bridge and other infrastructure.
While the shield will absorb the damage caused by disasters, other side-effects such as nuclear fallout or injury to residences adjacent to a lab accident will not be mitigated.
As with most other defensive buildings, the Shield Generator is delivered via glider upon construction, and takes a short while to activate.