The Magistracy lies to the west of Arrival, and its capital is One, the first of the four giant numbers. Due to its heavy reliance on magic, the Magistracy is generally considered the most powerful of the four nations. It is also the most restrained, however, as the Keepers tend to avoid using magic—and prevent others from using magic—as much as pos-sible. The Magistracy is somewhere between an oligarchy and a democracy, as only wizards and sorcerers have the right to vote. Non-magical beings are known as nomags, and while they are (mostly) free people, they are second-class citi-zens. On the other hand, arcane magic-users are expected to register if they want to travel through Magistracy territory, much as we might expect one to apply for a permit for a concealed weapon. The Magistracy has attempted to take over the other nations in the past, with some success, to extend their regulation of magic use. At the moment, they are experi-encing some success expanding into the Free Cities, partly because of the hardship caused by the Broken River. The Magistracy prefers intrigue to outright force.
(source: The Player's Guide to the Glass Guarded World)