Portal

The mages who specialize in this discipline are the most respected, well payed, and steadily employed mages. These mages will spend their lives in cities making and maintaining portals. They will spend huge amounts of concentration, coordination and frequently, time, to get the correct portal open. Loosing a connection is catastrophic, so the ability to pass the maintenance onto another is crucial. Strangely, it doesn't require focus to maintain. The mages find other things to do on the side. Portals are the heart of a city. However are huge security risks, being placed in areas that can easily transport trade goods, and have ease of access. So they are put in special multi layered fort, that can be defended on either side to. The nearby buildings being a good distance from the fort, and most are filled to the brim storage buildings. The forts inner courtyard is flat and open giving no cover to what inside. One major problem is any portal mage can take over the portal if its released it. Another problem is you can attack the mage and stop them from maintaining the spell. Although it is hard to get near the mages as they are off somewhere else easy to defend. The bigger and or richer Adventuring Monster Hunters Society will actually take the more adventurous portal mages with them. Access to an emergency portal is amazing, but it also offers them the ability to bring their larger hunts back quicker. The bigger the better.