GM Onit and I did an event the other day, it involved two rogues that roamed Ojaroad in search of lonely travelers. We then mugged them and used a GM command to take small items. The players didn't mind us taking those, but just enjoyed the event, chasing us down and eventually managing to retrieve the items. This lead to me thinking of the following structure.
A thieves picpocket skill is in relation with the weight of an item. After all, t's easier to take a tria then a double bladed battle axe, someone may notice. When a thief uses ahis "/pickpocket target" command, he gets a list of items he can try and steal and chooses one of them. With a low skill, you simply can not select a sword, or axe, only small loot and tras will appear. Once your level increases, you can try and steal heavier items.
Ofcourse there is a chance that any player is smart enough to see through a pickpocketeer (<--- new word as of today) And they in turn ave some random "protection" stat that still needs implementing. This stat decides wether or not a pickpocketeer is noticed. "[name] has taken 120 trias from you!" message will appear on screen when something gets stolen. If you notice, the item remains safely in your inventory.