Field Bridge



Field Bridges are Combine force-fields that act as a means of reaching otherwise inaccessible areas that are used inside the Citadel. Field bridges can only be activated if two power generators within the immediate vicinity are started. It is seen within the Citadel's core that field bridges can be bisected, and each half can rotate without the need for extra machinery at the new, broken end, to move into a specific position. The generators powering these bridges can only be activated by the Combine Energy Orbs taken from the power streams found in the Citadel.

Forcefield bridges are prevalent in the Citadel core in Half-Life 2: Episode One, where Gordon Freeman must reactivate several deactivated ones to proceed. Stalkers can use their laser to destroy the energy orbs powering bridge generators, and use this ability to hinder Gordon's progress.