Stunning Reversal

• WWizards of the Coast2018-06-08
  Official Ruling
  While the replacement effect it creates lasts until end of turn (or until the event it replaces), Stunning Reversal is exiled as it resolves.
• WWizards of the Coast2018-06-08
  Official Ruling
  For your life total to become 1, you gain or lose the appropriate amount of life. For example, if your life total is 4 when Stunning Reversal’s effect applies, it will cause you to lose 3 life; alternatively, if your life total is -5 when it applies, it will cause you to gain 6 life. Other cards that interact with life gain or life loss will interact with this effect accordingly.
• WWizards of the Coast2018-06-08
  Official Ruling
  Stunning Reversal’s effect does nothing if you concede the game. A player who concedes leaves the game.
• WWizards of the Coast2018-06-08
  Official Ruling
  Stunning Reversal’s effect applies any time you would lose the game, even if you’re not losing due to your life total being 0 or less.
• WWizards of the Coast2018-06-08
  Official Ruling
  If an effect says that an opponent wins the game, Stunning Reversal’s effect doesn’t apply.
• WWizards of the Coast2018-06-08
  Official Ruling
  If an effect says you can’t lose the game, Stunning Reversal’s effect can’t apply.
• WWizards of the Coast2018-06-08
  Official Ruling
  If each player would lose the game at the same time, but Stunning Reversal’s effect applies to you losing the game, you win the game as soon as everyone else has lost the game. This is true even if you’d lose the game immediately afterwards, perhaps because you don’t have seven cards in your library to draw or because you couldn’t gain life to raise your life total to 1.
• WWizards of the Coast2018-06-08
  Official Ruling
  In a Two-Headed Giant game, if a rule or effect says that your team or your teammate loses the game, your team won’t lose the game, but only you draw seven cards and only you gain or lose life to make your team’s life total become 1.
• WWizards of the Coast2018-06-08
  Official Ruling
  If you have fewer than seven cards in your library, you’ll lose the game immediately after applying Stunning Reversal’s replacement effect.

Rulings via Scryfall