If an effect says that a player can’t lose life, that player can’t make an exchange such that the player’s life total would become lower; in that case, the exchange won’t happen. Similarly, if an effect redistributes life totals, a player can’t receive a new life total such that the player’s life total would become lower. In addition, a cost that involves having that player pay life can’t be paid.
May 3, 2019 · War of the Spark
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won’t trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.
January 25, 2019 · Ravnica Allegiance
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won't trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.
February 1, 2014 · Born of the Gods
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won’t trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.
September 30, 2011 · Innistrad
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won't trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.
June 17, 2011 · Commander 2011
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger
April 1, 2011 · Duel Decks: Knights vs. Dragons
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won't trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.
February 4, 2011 · Mirrodin Besieged
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won’t trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.
October 1, 2010 · Scars of Mirrodin
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger
July 16, 2010 · Magic 2011
If a source would deal 0 damage, it does not deal damage at all. That means abilities that trigger on damage being dealt won't trigger. It also means that replacement effects that would increase the damage dealt by that source, or would have that source deal that damage to a different object or player, have no event to replace, so they have no effect.