This spell secures an area from magical intrusion by means of teleportation, gates, or dimension doors. The area extends out from the caster 10 yards per level in all three dimensions and is not impeded by walls, doors, or other surfaces.
When in operation, the spell prohibits the use of teleport spells (including teleport without error and mage tunnel) into the region. Dimension doors will also not function within the proscribed region. Attempts to use these spells to enter or leave the affected area fail completely.
In order to use gate spells or similar magics that open portals into other planes, the caster of the gate must make a saving throw vs. spell to succeed. Failure indicates the spell fails but is expended anyway. Success allows the use of the gate. Further attempts require additional saving throws.
Spells that tap the Ethereal Plane (such as vanish) and items such as armor of etherealness function normally, as do ethereal creatures. Other extraplanar creatures also function normally, though they may not gate or teleport.
The proof against teleportation spell can be discontinued at any time by its caster. It may also be brought down by a dispel magic in the standard fashion. A limited wish or wish allows a teleport to function within the secured area.
The material component of the spell is 10 lbs. of sugar, salt, or other granular material stuffed into a 5-lb. sack and dropped at the center of the spell's area of effect.
Notes: Rare spell from the Forgotten Realms setting. Known to be in Elminster's Traveling Spellbook.