lockpicks and locks, there I broke down locks in five simple levels of complexity. Then I had an example of a lock maker...cause they don't make themselves. I'll use Frower as my lock maker example and game stats will be in italics.
Frower of Ellon
Lock maker for 15 years. He has three styles of locks he makes, the simple catch lock which is a simple lock that keep out the curious, but not those who are determined. A good thief can make do and sometimes manipulate this kind of lock with household items or...gasp...jimmy the lock. It is a cheap lock and comes with two keys. This would be considered a simple lock that provides no penalty and on failures the lock in not likely to jam.
Frower makes a more complex three tumbler lock. This lock take some skill to release. He makes the lock chamber large enough for needle traps. Where as Frower will now build the trap in he knows how much space to leave to allow that addition. This kind of lock comes with two keys also. This lock would be considered a difficult lock and give the player a -10% penalty. However, if the player has been successful with Frower's locks in the past there will be no penalty.
Both these locks are fairly common and known to thieves in the city. They look for FE engraving above the keyhole. A few of the more skillful thieves have copies of the keys that will open the locks. A single key may open 10% of the doors in the city without ever having to use a lockpick. Frower cannot make an endless combination for his cheap locks so he has a set of five different sets. For the standard set of locks he makes 10 different combinations. More combinations cost him time and money. If people wanted real security they would spend a little more on a complex lock below.
Frower also does special orders for more complex locks. In these cases he must have the container in the shop to shape the lock. These locks are unique and difficult to pick. More often than not a clumsy attempt to pick this type of lock will result in a pick breaking off inside the lock, thus jamming the mechanisms. These locks take more time to fashion and Frower can add simple traps to the locking mechanism. One key for each lock. This would be considered a complex lock providing the picker a -20% penalty.
Why go into this much detail over locks? I like to add sub game to my game...sometimes. If there are a few thieves in the party they enjoy this kind of detail. If the don't like it I toss over my shoulder for another time. The main reason I like it is it adds more possibilities to urban adventures I already love. I can think of a dozen plots that could involve a lock maker. Having details like this can add an an unexpected element to your game.