First, if an effect that’s causing damage to be dealt states that excess damage that would be dealt to a permanent is dealt to another permanent or player instead, the damage event is modified accordingly. If the first permanent is a creature, the excess damage is the amount of damage in excess of what would be lethal damage, taking into account damage already marked on the creature and damage from other sources that would be dealt at the same time. (See rule 120.6.) Any amount of damage greater than 1 is excess damage if the source dealing that damage to a creature has deathtouch. (See rule 702.2.) If the first permanent is a planeswalker, the excess damage is the amount of damage in excess of that planeswalker’s loyalty, taking into account damage from other sources that would be dealt at the same time. If the first permanent is a battle, the excess damage is the amount of damage in excess of that battle’s defense, taking into account damage from other sources that would be dealt at the same time. If the first permanent has multiple card types from among the list of creature, planeswalker, and battle, the excess damage is the greatest of the calculated amounts for each of the card types it has.
February 15, 2021 · Cascade Update
First, if an effect that’s causing damage to be dealt states that excess damage that would be dealt to a permanent is dealt to another permanent or player instead, the damage event is modified accordingly. If the first permanent is a creature, the excess damage is the amount of damage in excess of what would be lethal damage, taking into account damage already marked on the creature and damage from other sources that would be dealt at the same time. (See rule 120.6.) Any amount of damage greater than 1 is excess damage if the source dealing that damage to a creature has deathtouch. (See rule 702.2.) If the first permanent is a planeswalker, the excess damage is the amount of damage in excess of that planeswalker’s loyalty, taking into account damage from other sources that would be dealt at the same time. If the first permanent is both a creature and a planeswalker, the excess damage is the greater of those two amounts.
February 5, 2021 · Kaldheim
First, if an effect that’s causing damage to be dealt states that excess damage that would be dealt to a permanent is dealt to another permanent or player instead, the damage event is modified accordingly. If the first permanent is a creature, the excess damage is the amount of damage in excess of what would be lethal damage, taking into account damage already marked on the creature and damage from other sources that would be dealt at the same time. (See rule 120.6.) If the first permanent is a planeswalker, the excess damage is the amount of damage in excess of that planeswalker’s loyalty, taking into account damage from other sources that would be dealt at the same time. If the first permanent is both a creature and a planeswalker, the excess damage is the greater of those two amounts.
July 3, 2020 · Core Set 2021
First, if an effect is causing damage to be dealt to a creature and that effect specifies that excess damage is dealt to another object or player instead, the damage event is modified to deal damage accordingly. Excess damage is damage greater than lethal damage that would be dealt to a creature. Lethal damage is the creature’s toughness minus damage marked on that creature and other damage being dealt to it at the same time as this damage. Any damage greater than 1 is excess damage if the source dealing that damage has deathtouch.
April 17, 2020 · Ikoria
First, if an effect is causing damage to be dealt to a creature and that effect specifies that excess damage is dealt to another object or player instead, the damage event is modified to deal damage accordingly. Excess damage is damage greater than the creature’s toughness, taking into account damage marked on that creature and other damage being dealt to it at the same time as this damage. Any damage greater than 1 is excess damage if the source dealing that damage has deathtouch.
July 12, 2019 · Core Set 2020
First, damage is dealt, as modified by replacement and prevention effects that interact with damage. (See rule 614, “Replacement Effects,” and rule 615, “Prevention Effects.”) Abilities that trigger when damage is dealt trigger now and wait to be put on the stack.