Oathbreaker Oathbreaker is a fun, fast, and casual multiplayer format where Planeswalkers rule! Choose a Planeswalker as your Oathbreaker, then select an instant or sorcery card as your signature spell. Armed with the rest of your 60 card singleton deck, battle it out with friends in 30-60 minute games in this format! RSVP on our Meetup now! Basic Rules Each