Hallucinatory Terrain (Illusion)
Level: Mage 4, Bard 4, Twilight Huntsman 4
Mana: 16. Long duration. Base Success: 75%.
  Casting this spell weaves an elaborate illusion of terrain features over a globe 30 feet in radius, with a point of origin that you select. The illusory terrain appears only in map squares containing a normal floor, and can simulate magma, a deep pool of water, a gaping chasm, entangling webs or sticky slime. Just like an illusionary creature, the effects of this terrain are real in the case of those who believe in it, and can inflict psychosomatic damage normally, though it can have no effect on those who are able to see through the illusion. Like the spell phantasmal force, this illusion affects only sight and hearing, and is thus automatically seen though by sharpened senses, blindsight, tremorsense or scent, as well as magics designed specifically to penetrate illusions, like true seeing.
   However, hallucinatory terrain does not require concentration or line of sight in order to maintain.