Some costs are represented by {0}, or are reduced to {0}. The action necessary for a player to pay such a cost is the player’s acknowledgment that they are paying it. Even though such a cost requires no resources, it’s not automatically paid.
May 3, 2019 · War of the Spark
If an effect sets a player’s life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
January 25, 2019 · Ravnica Allegiance
If an effect sets a player's life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
February 1, 2014 · Born of the Gods
If an effect sets a player’s life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
September 30, 2011 · Innistrad
If an effect sets a player's life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
June 17, 2011 · Commander 2011
If an effect sets a player’s life total to a specific number, the player gains or loses the necessary
April 1, 2011 · Duel Decks: Knights vs. Dragons
If an effect sets a player's life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
February 4, 2011 · Mirrodin Besieged
If an effect sets a player’s life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
October 1, 2010 · Scars of Mirrodin
If an effect sets a player’s life total to a specific number, the player gains or loses the necessary
July 16, 2010 · Magic 2011
If an effect sets a player's life total to a specific number, the player gains or loses the necessary amount of life to end up with the new total.
February 1, 2010 · Worldwake
Damage dealt to a creature or planeswalker doesn't destroy it. Likewise, the source of that damage doesn't destroy it. Rather, state-based actions may destroy a creature or planeswalker, or otherwise put it into its owner's graveyard, due to the results of the damage dealt to that permanent. See rule 704.