User:Myrkraverk/Astral Barrier

Many people have commented on how teleport completely ruins the concept of a fortress.

In a world where an enemy can teleport themselves into a stronghold it stands to reason people will also protect the fortress for this kind of attacks. Even the poorest farmer will make some effort at protecting his home from magical incursions.

Enter the Astral Barrier. By building walls, doors and anything that needs to prevent a teleport or a walk on the astral plane with specific patterns, these can then be blessed by the local priest to form an astral barrier.  Not only preventing teleportation through them, but also creating a barrier on the ethereal and shadow planes.

In rural areas where a wizard with teleportation or enemies that otherwise move beyond the mortal plane people may have forgotten why brick walls have certain pattern or the local spellcaster doesn't understand the purpose, there may be gaps in the barrier. These allow sufficiently high level casters to teleport through the barrier. Each such incomplete barrier has a fixed DC - established at the time the house was built.