fallout
Gameplay articles
Fallout 3Lock
Fallout: New VegasLock
Fallout 4Lock
Fallout 76Lock

Locks are found throughout the wasteland on doors, safes and boxes.

Other

In Fallout, Fallout 2 and Fallout Tactics, instead of a mini-game, a lockpick skill roll will take place every time the skill is used on a door or a container. A successful roll will open the lock, failure will not. A critical failure will either break the lockpicks or jam the lock itself, rendering it unavailable until the next day.

The Lockpick skill can be used on unlocked doors and containers as well, and locking them will give the same amount of experience as unlocking a locked one (25 XP). Note that each door or container can only give experience once via lockpicking.