When used by a priest, this spell can detect if a person or monster is under the influence of a charm spell, or similar control such as hypnosis, suggestion, beguiling, possession, etc. The creature rolls a saving throw vs. spell and, if successful, the caster learns nothing about that particular creature from the casting. A caster who learns that a creature is being influenced has a 5% chance per level to determine the exact type of influence. Up to 10 different creatures can be checked before the spell wanes. If the creature is under more than one such effect, only the information that the charms exist is gained. The type (since there are conflicting emanations) is impossible to determine.
The reverse of the spell, undetectable charm, completely masks all charms on a single creature for 24 hours.
Notes: Common for clerics and druids (PHB).