An energy shield is a barrier that protects an area from energy attacks. Normally invisible to the naked eye, it is projected from a shield generator through a series of emitters that absorbs and dissipates incoming blasts from energy weapons. If a shield is struck too many times, it can overload and fail. Energy shields are able to slow projectile weaponry, thus reducing potential damage, but cannot prevent an impact from landing. Utilizing similar technology, energy shields can also be used to prevent the escape of gas from an environment. In this context, they are known as air shields.