The locksmith is a knowledge of locks, their manipulation and their design. The making of a lock requires you to have the blacksmith skill too. Once a lock is made it has its difficulty set by the skill of the designer.
To set a locks difficulty the users: focus + locksmith levels + blacksmith levels + 1 per 3 days of design and construction. A locksmith workshop can add a bonus to the users levels at 1 per 4 levels of the shop and decrease the time to construct by 1 day per 6 levels.
To open a lock the user must have lockpicks and rolls: awareness + locksmith levels + blacksmith levels + 1d20 per 3 minute (game time) vs the locks difficulty.
Score higher than the difficulty of the lock to open it. A tie or failure goes to the lock and you can try again. Failure by 10 or more means you have broken your picks and need a new set, Failure by 20 mean you have broken the pick inside the lock and jammed it....time to break it.