You cause a single target creature's shadow to become a temporary gateway to a pocket realm within the Shadowfell. The target must make a Wisdom saving throw. On a failure, they are pulled into the gateway. Inside the pocket realm, the target sees a deserted, gloomy duplicate of the real world, while shadowy phantasms stalk and taunt it without causing real harm.

On each of its turns, the target can use its action to attempt a Wisdom saving throw, ending this effect on a success. When the target returns to the real world, it must succeed on another Wisdom saving throw or become frightened for 1d4 rounds. Upon leaving the pocket realm, the target reappears in the spot it had been in when the shadow well spell was cast. If this space is occupied, it instead appears in the nearest unoccupied space to that point. Spells and abilities that move a creature within a plane, such as teleport and dimension door, do not help a creature to escape a shadow well spell, although a plane shift spell allows it to flee to another plane as normal. The target may still become frightened upon leaving in such a manner.