Spectral Ward

Spell · Necromancer level 21 · (obscure)
Mana: 36Int: 25Wis: 23(28% per practice)
Requires: dread portent

The 'spectral ward' spell creates a bounded region into which ghosts, spectres, spirits, and other ethereal creatures cannot cross. Even the weakest spectral ward absolutely prevents entry: it is as though the warded region simply ceases to exist for ethereal creatures.

Note that a ward can be created with ethereal creatures inside it, but once a creature leaves it cannot return.