Periapt of Proof Against Lies 2014
Wondrous Item, rare
A pendant fashioned from the claw or horn of a Pact Drake (see Creature Codex) is affixed to a thin gold chain. While you wear it, you know if you hear a lie, but this doesn't apply to evasive statements that remain within the boundaries of the truth. If you lie while wearing this pendant, you become poisoned for 10 minutes.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details