Quiet Aura

The character or object with a quiet aura will not detect as their specific creature type. Very, very few creatures are able to masquerade the fundamental type of being that they are. It cannot be discerned with Aura Sight.

D20 Quiet Aura Mechanics

Foils the use of Detect Evil/Good, unless they are in direct service to a patron of that type, or are using special abilities that channel that connection.

Incarna Core Quiet Aura Mechanics

Need ideas for role-playing this? See the Roleplaying your Character's Capabilities or ask the Game Master how it is best expressed in your Setting.No matter what restrictions exist in the setting you use, many GMs will allow anything with the right context or character backstory.