Efforts to conserve the invisible structure of the Prime Material Plane date back to the early aeons of organized wizardry. Prevailing magical theory suggests that physical portation across the material barrier to the otherworlds leads to a sort of decomposition of that barrier. As the occurrences of portation to the outer lands increase -- leaving more rotting punctures and pocks -- the barrier becomes compromised so that all manner of vagabonds from Outside can find their way in to the Material. The manufacture of new permanent gates is strictly forbidden, and various magical buffers and boundaries confound most forms of temporary portals, so that special knowledge is required to bypass them effectively.
- Knowledge of the location of existing sanctioned permanent gates may be a requirement to reach certain otherworld destinations.
- The magical means to bypass the old wizard-boundaries would be extremely rare and valuable.
- Such information might be: (a) lost or forgotten, (b) protected by magical means, (c) part of an ancient hoard, (d) available for an astronomical price.
- Certain magic-users would devote their study and practice to conserving and repairing the wizard-boundaries and would protect them ferociously.
- Permanent gates need wardens to prevent vagabonds from accessing the Material.