A stalwart upgrade consists of inertial dampeners spread across the body, often augmented by armored boots that can deploy stabilizing struts. When activated as a move action, these dampeners monitor your bio-signs, impeding any sudden movements that you didn’t initiate. While activated, the stalwart upgrade consumes 1 charge per minute, and each time you are targeted by a bull rush, reposition, or trip combat maneuver, the upgrade consumes an additional charge to grant you a +4 circumstance bonus to your AC against the combat maneuver.