This is the reverse of the zone of truth spell. Everyone within the area of effect knows immediately that they may speak only lies. They can decide exactly what they say and how they say it, but every statement must be a lie. Because questions, suppositions, and exclamations are not statements, they are not affected. The Dungeon Master should carefully examine every statement and classify it as true, false, or an exception to the spell. For example, the statement "I can only lie" is a true statement under the influence of this spell and, therefore, cannot be spoken.

You create a magical zone that guards against truth in a 15-foot-radius sphere centered on a point of your choice within range. Until the spell ends, a creature that enters the spell's area for the first time on a turn or starts its turn there must make a Charisma saving throw. On a failed save, a creature can't speak a deliberate truth while in the radius. You know whether each creature succeeds or fails on its saving throw.

An affected creature is aware of the spell and can thus avoid answering questions to which it would normally respond with a lie. Such a creature can be evasive in its answers as long as it remains within the boundaries of the deception.