Sign of Koth

You invoke the twilight citadels of Koth to create a field of magical energy in the shape of a 60-foot-radius, 60-foot‑tall cylinder centered on you. The only visible evidence of this field is a black rune that appears on every doorway, window, or other portal inside the area.

Choose one of the following creature types: aberration, beast, celestial, dragon, elemental, fey, fiend, giant, humanoid, monstrosity, ooze, plant, or undead. The sign affects creatures of the chosen type (including you, if applicable) in the following ways:

• The creatures can’t willingly enter the cylinder’s area by nonmagical means; the cylinder acts as an invisible, impenetrable wall of force. If an affected creature tries to enter the cylinder’s area by using teleportation, a dimensional shortcut, or other magical means, it must make a successful Charisma saving throw or the attempt fails.

• They cannot hear any sounds that originate inside the cylinder.

• They have disadvantage on attack rolls against targets inside the cylinder.

• They can’t charm, frighten, or possess creatures inside the cylinder.

Creatures that aren’t affected by the field and that take a short rest inside it regain twice the usual number of hit points for each Hit Die spent at the end of the rest.

When you cast this spell, you can choose to reverse its magic; doing this will prevent affected creatures from leaving the area instead of from entering it, make them unable to hear sounds that originate outside the cylinder, and so forth. In this case, the field provides no benefit for taking a short rest.