Aura

An aura, also known as a dweomer, was a magical emanation from a person or object that was supernaturally detectable. Many divination spells functioned by recognizing auras. Undead, liars, secret doors, magical persons and items, and lawful, chaotic, good, and evil creatures all emitted auras that could be detected by the right magic. The aura of magical items and spells usually revealed the school of magic to which the magical effect belonged.

Clerics always had particularly powerful auras that matched the alignment of their deity. Many paladins were surrounded by auras of courage.