Welcome to Nowhere

This post is gaming related , I think this is the first one that is fully and totally related the Games, this one in particular is a D&D 3rd edition game.
I came up with this concept cause I was tired of the cliché of the thieves guild running the city from the shadow or every player that plays a rouge coming with the “oh ,I stole that” excuse for items he wants.
As this is a magical world, the local police will use magic to rein in the criminal population.
The idea is relatively simple, when ever a new member joins the Thieves guild, he receives a “Mark of Justice” spell cast on him, the Thieves guild has to pay for the cost of the spell,and that also helps reduce the amount of money they can horde.
A rouge unwilling to participate in the ceremony he will be arrested,sedated and have the ceremony cast on him while he is helpless (there for does not get a Saving Throw).
Rouges in this city earn XP as lock smiths , jugglers, Security inspectors and so forth, essentially all the things a thief will do (except pick pockets) but on the legal side and being commissioned for it.

The “Mark of Justice” is a high level spell (5th) that requires a high level cleric to cast it, and it requires very powerful spells to break and dismiss this one.
Of course in order to allow some flexibility in the game you always add the human factor, some clerics will be greedy and will take the money and “fake” the ceremony,or get paid to remove such a mark, but as those cost quite a bundle and the ceremony is supervised by the police , it makes for a more story driven event.