Hallucinatory Terrain (spell)
Hallucinatory Terrain enables a cosmetic alteration to existing terrain, so that the caster is able to add rock, water, vegetation and shape within the affected area of the spell.
| Range | 40 ft. per level |
| Duration | 25 rounds per level |
| Area of Effect | 20 ft. diameter cube per level |
| Casting Time | 2 rounds |
| Saving Throw | none; see text |
| Level | illusionist (3rd) |
A feature may be as tall as the "cubes" of effect added atop one another—thus up to 20 feet per level—or as wide and as deep as placement of each cube allows (a pond or a hole 20 feet across, for example, could be up to 20 feet deep per level).
The spell will create grass, living trees, lush jungle, swamp and so on, even natural fruits and other foods, which may be consumed by those entering the terrain, seeming to be utterly real. Such edibles would not actually provide sustenance, however.
This sense that the terrain is "real" will apply to every aspect of the terrain; creatures can swim in created ponds, can climb down into crevices or caves, can climb up on rocks, even walk out into what would be nothing but air, should the spell—for instance—extend a cliff outwards over a gorge … because in fact the creature would be doing so only within their own mind.
If, however, the application of the illusion should somehow result in something that is physically impossible—spanning the gorge so that a person believing the hallucination to be real were to try to cross to the other, actually real side, said creature must make saving throw or else potentially tumble to their death from the real terrain (or some other logical conclusion, given the circumstance in question). A save would not reveal the illusion, but it would suggest to the creature that the bridge was unsafe, would for some reason not support the creature’s weight and so on.
Equally true, creatures who ‘fall’ or ‘drown’ or otherwise might injure themselves in an hallucinatory terrain (one attempts to hang himself from a tree, for instance) are also entitled to a saving throw. In the case of possible death, a fail indicates that they suffer 2d6 per their own level in damage; if in a case where death was very unlikely to occur, a failed save would result in only 2d4 damage.
A successful save would then indicate the creature somehow freed themselves from the circumstance and are thus "miraculously" safe.
There is a save against believing the illusion of hallucinatory terrain only if it is somehow proven to be an illusion—either by means of the spell detect illusion or similar case, or if the viewer knows the terrain for what it is from previous experience (and knows very well there can be no pond, rock spire, cave or other feature in this particular place). This would also apply if the terrain magically re-invented itself as the viewer witnessed the change.
In either case, a saving throw would then permit the viewer to "see" the illusion for what it was … a failed save would mean the viewer is yet affected by the terrain as would any unknowing creature be.
The actions of others, believing or not, will always be interpreted by unaware creatures within the framework of the illusion. Thus, the illusionist walking through a pond—for the illusionist is always immune to their own illusion—would be seen as swimming across it, while a creature moving through an overgrown area would appear to be fighting the trees, and so on. The spell will also cause such movement to be regular and believable. A creature crossing a 20 feet area with a 100 feet rock spire in it would appear to be climbing the spire for the expected time required—for passage of time in the mind of the affected viewer is also altered. Thus, though only a round might pass, for the viewer is may seem like 20 minutes—if the illusion of reality demands that it must have been so.
This will occasionally create some difficulties in interpreting what happens when and how, which the DM must be prepared to reconcile.
