Listening Coin(Song and Silence: A Guidebook to Bards and Rogues)
Level: Bard 4,
Components: V, S, M,
Casting Time: 1 action
Range: See text
Effect: Magical sensor
Duration: 1 hour/level
Saving Throw: None
Spell Resistance: No
You can turn two ordinary coins into magic listening devices—one a sensor and the other a receiver.
After casting the spell, you simply give the sensor coin away, either surreptitiously or overtly.
By holding the receiver coin up to your ear and making a successful Listen check, you can hear whatever is transpiring near the sensor.
If the sensor coin is in a pocket, pouch, or sack, the DC for the Listen check increases by +5 for all but the most obvious sounds.
The coins continue to function no matter how far apart they are, although they fall silent if they're on different planes.
Lead sheeting or magical protection (such as antimagic field,
mind blank, or nondetection) blocks the transfer of sound.
Any creature with an Intelligence score of 12 or higher can notice that a coin has a magical sensor by making a successful Scry (or Intelligence) check (DC 20).
The sensor can be dispelled.