Can I add Colossus Slayer damage on my regular turn and then again on my reaction? (ie comander’s strike, opp. attacks)
— Jeremy Crawford (@JeremyECrawford) December 4, 2016
A Ranger with Colossus Slayer: As a #DungeonMaster, I wasn’t sure if this could be used by the Ranger on both their own turn, and an attack of opp.
— Rob 🎲 🍷 🏳️🌈 (@DiceRefgemlin) October 9, 2018
My answer is the definitive one. Colossus Slayer doesn't say anything about the turn being your turn.
— Jeremy Crawford (@JeremyECrawford) October 11, 2018