Nightmare

5th-level illusion

Casting Time 10 minutes

Range touch

Components V, S, M

Duration Concentration, up to 1 hour

At the end of casting the spell, you touch a sleeping creature. As long as contact and concentration are maintained, the creature has horrible visions in its sleep. If the visions last the full hour, the creature gets no benefit from its rest and its hit point maximum is reduced by 1d10. If this effect reduces a creature to 0 hit points, it dies. The reduction to the target’s maximum hit points lasts until removed by greater restoration or similar magic.