717. Additional Rules : Handling Illegal Actions
717.1.
If a player realizes that he or she can‘t legally take an action after starting to do so, the entire
action is reversed and any payments already made are canceled. No abilities trigger and no effects
apply as a result of an undone action. If the action was casting a spell, the spell returns to the zone it
came from. The player may also reverse any legal mana abilities activated while making the illegal
play, unless mana from them or from any triggered mana abilities they triggered was spent on
another mana ability that wasn‘t reversed. Players may not reverse actions that moved cards to a
library, moved cards from a library to any zone other than the stack, or caused a library to be
shuffled.
717.2.
When reversing illegal spells and abilities, the player who had priority retains it and may take
another action or pass. The player may redo the reversed action in a legal way or take any other
action allowed by the rules.