"To confront the Imperial threat, we the Three Kings have declared the Frigid Mountains and its lesser regions to be portioned and sold to companies willing to build mining operations. Each portion shall be limited in size to determine easily and quickly-accessed minerals and ores of importance, such as Adamantine and Gold. Mines that have reached their size limit that yield less-important ores shall be mined on a rotational system, so as to not have all vital resources located in one place."
This section of the Domain Mining Initiative laid out the gist of the act. What it did not foresee, however, was the potential for the abandoned mines waiting for their rotation schedule to come around to be nonetheless occupied, though not by approved miners. Beast tribes, bandits, and landslides were unfortunate incidents that needed taking care of to secure the resources within. Unfortunately, with the bulk of trained guards being sent to the front lines, local barracks don't often have the manpower necessary to deal with the threats. As such, these assignments were often given to burgeoning adventurers to let them get a start on their career. Soldiers on "home duty" would also be sent as part of their continuing service.