Killing Wave | Magic: The Gathering
Formats Killing Wave is Legal in
Official Oracle Text for Killing Wave
Official Rulings for Killing Wave
5/1/2012 : A player may choose to pay life for some creatures and sacrifice the rest. It's not an all-or-nothing decision.
5/1/2012 : You can't pay more life than you have.
5/1/2012 : If you can't sacrifice a creature (perhaps because of Sigarda, Host of Herons), you can choose not to pay life and nothing will happen.