Mirage Arcane

You make natural terrain in a 150-foot cube in range look, sound, and smell like some other sort of natural terrain. The terrain's general shape remains the same, however. Open fields or a road can be made to resemble a swamp, hill, crevasse, or some other difficult terrain. A pond can be made to seem like a grassy meadow, a precipice like a gentle slope, or a rock-strewn gully like a wide and smooth road. Manufactured structures, equipment, and creatures within the area aren't changed in appearance.

The tactile characteristics of the terrain are unchanged, so creatures entering the area are likely to see through the illusion. If the difference isn't obvious by touch, a creature carefully examining the illusion can attempt an Intelligence (Investigation) check against your spell save DC to disbelieve it. A creature who discerns the illusion for what it is sees it as a vague image superimposed on the terrain.

At Higher Levels. When you cast this spell using a spell slot of 5th or 6th level, the duration is 10 days and the area increases to a 600-foot cube. When you cast this spell using a spell slot of 7th level, the area increases to 1 square mile and you can alter the appearance of structures, or add them where none are present, but the spell still doesn't disguise, conceal, or add creatures. In addition, the illusion can now include audible, visual, tactile, and olfactory elements, so it can turn clear ground into difficult terrain (or vice versa) or otherwise impede movement through the area. Any piece of the illusory terrain (such as a rock or stick) that is removed from the spell's area disappears immediately. Creatures can also no longer discern the difference between the illusion and reality without special abilities. Creatures with truesight can see through the illusion to the terrain's true form; however, all other elements of the illusion remain, so while the creature is aware of the illusion's presence, the creature can still physically interact with the illusion. When you cast this spell using a spell slot of 8th level, the duration is 30 days. When you cast this spell using a spell slot of 9th level, the duration is 1 year.