Illusion

Illusions are magical effects that alter perception, causing creatures to see, hear, or otherwise sense something that does not exist or misinterpreting what is real. Unlike physical transformations or conjured objects, an illusion has no true substance; it is a deception of the senses rather than a change in the world itself. It can fool individuals, groups, or even entire regions depending on its power and complexity, but its effectiveness depends on the observer's ability to perceive and interact with it. Illusions fall into two broad categories: those that create something entirely false and those that distort reality. The first includes phantasmal images, sounds, and sensations that have no physical presence. The second alters existing sights, sounds, and textures, hiding or disguising things rather than inventing them.

A creature subject to an illusion experiences it as real until they have reason to doubt it. Some illusions end when their false nature is exposed—if an illusory bridge is stepped upon, the illusion fails because it provides no support. Others persist even when disbelief is strong, continuing to affect those who cannot overcome their own senses. Spells and abilities that enhance perception or provide supernatural sight may reveal illusions, but not all magic can easily unravel them.

Illusions do not affect the physical world. A false wall blocks sight but not movement. An illusory monster roars and charges but does not strike or leave footprints. Even powerful illusions that include sound and scent cannot produce true force, only the convincing image of it. However, illusions are not always harmless—if an illusion compels a victim to react in fear, confusion, or self-harm, the consequences may be just as real as if the illusion were tangible.