Lockpicking is a type of skill that players in Fallout 3 can use to unlock doors and various containers. Players who add extra points into this ability will face less difficulty when opening locks and be able to break into to those that require a much higher level to access.The Vault: Fallout 3 Wiki: Lockpick

Players attempting to pick a lock will have to pass a mini-game in which they must place a bobby pin and screw driver inside the lock and properly manipulate it until it opens. Being careless and impatient will likely result in a broken pin so the best way to approach lockpicking is to jimmy the lock until either the controller starts to vibrate or the pin starts to shake. If either of these things happen, ease off on the screw driver and re-orient the pin at a different angle. The longer you can turn the screw driver without the pin shaking, the closer you are to picking the lock.The Vault: Fallout 3 Wiki: Lockpick