Has anyone introduced a thieves guild into Diamond Lake?
I'm sure that the Thief's Guide had population to members and level splits but that hidden in my attic somewhere, guarded by a tribe of pygmeys that hide in all the junk and survive on spiders and the odd bird.
I believe this has been touched upon in months past so a quick search on "thieves' guild Diamond Lake" should garner some results.
To summerize, Diamond Lake doesn't have a thieves' guild of its own. I don't see Diamond Lake fitting the socio-economics need for such a guild. A "thieves' guild" suggests a population base large enough that petty thievery is profitable enough for charismatic/intimidating personas to organize these thieves into a collective union of sorts; where the percentage skimmed off the top of the thefts can support the infrastructure of the guild and keep the members motivated to continue.
Diamond Lake is a mining town with its labour force recruited from debtor prisons and displaced people who cannot find more desireable work. By inference, the town is poor and poor towns don't spawn "thieves' guilds".
Diamond Lake is instead an environment where charismatic/intimidating people can control segments of the population, typically those under their "employ". The various Mine Managers of Diamond Lake have the resources and influence to dictate the style of crime allowed within Diamond Lake. The more ruthless managers, such as Balabar Smenk, will fill roles similar to "bosses" of early 20th century Chicago. They will have a small force of "thugs" that will monitor and manage the criminal elements of Diamond Lake so that new influences (say, PC rogues) to the "ecology of crime" don't disrupt their own order.
The most powerful of the "bosses" of Diamond Lake will have contacts with the real Thieves' Guild of the Free City. How the PCs interact with the bosses of Diamond Lake may establish a premise for interaction later in the campaign when the PCs are in the Free City. Plan ahead now and the payoff will be worthwhile.
I dropped hints in my game that Balabar Smenk was a "made man" with the guild in Greyhawk... I left it vague as to which guild he might be a member.
Otherwise, I didn't incorporate a true thieves' guild in Diamond Lake. I did however create an extortion ring that operated out of the emporium and used a couple of the NPCs there as mentors for the rogue PC.