Rod of Truth (5e Equipment)

Rod, rare (requires attunement)

As an action, you can touch a creature with this rod. That creature must succeed on a DC 13 Charisma saving throw or be unable to knowingly tell a lie for as long as you can maintain concentration, as if you were concentrating on a spell, for a maximum of 1 hour. An affected creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.