Glibness

D&D 2014 spell: Glibness. Source: Player's Handbook (2014). level 8, school Transmutation, casting time 1 action, range Self (point), duration 1 hour

Until the spell ends, when you make a Charisma check, you can replace the number you roll with a 15. Additionally, no matter what you say, magic that would determine if you are telling the truth indicates that you are being truthful.

Source: Player's Handbook (2014), p. 245 - Licenses and attribution