Spider Song

4th-level conjuration

Casting Time: 1 action

Range: 60 feet

Components: V, M (a leg from a spider or a tiny lute strung with spider silk)

Duration: Concentration, up to 10 minutes

You sing a piping tune and conjure shadows into enormous, ever-growing webs. The area within a 20-foot cube within range is filled with shadows, and the area is lightly obscured and provides half cover to any creature within. You may create a new cube of shadows in range every other round so long as you retain concentration, in which case the previous cube disappears 1 round later.

Cubes can overlap but there is no cumulative effect from it.

Each creature that enters the area or starts its turn in the area must make a Dexterity saving throw. On a failed save, the creature is incapacitated for as long as it remains in the shadows or until it breaks free. A creature incapacitated by the shadows can make a Strength check each round against your spell save DC. If it succeeds, it is no longer incapacitated.

The shadows can be removed from a single 20-foot cube with a daylight spell.