Heart of a Duelist

• WWizards of the Coast2024-11-08
  Official Ruling
  Playtest cards use a modified version of game symbols, such as and . These modified symbols should be treated as the standard symbols during play.
• WWizards of the Coast2024-11-08
  Official Ruling
  Playtest cards aren’t legal for play in any tournament format other than Mystery Booster Limited formats. On the other hand, we expect they will spice up a wide variety of non-tournament games (as long as everyone’s on the same page about using them!).
• WWizards of the Coast2024-11-08
  Official Ruling
  For many playtest cards, you’ll need to make a generous assumption that basic game rules would be updated to allow them to work. The Mystery Booster 2 Playtest Card Notes section (reproduced here in individual Gatherer rulings) provides guidance for fitting these cards into the existing rules structure.
• WWizards of the Coast2024-11-08
  Official Ruling
  If an effect instructs you to draw multiple cards, you draw those cards one at a time. Maybe after you draw that first card, a different part of your library seems like it has better vibes. Who knows?

Rulings via Scryfall