So let’s get to today’s question: what if the creature is being dealt damage from multiple sources at the same time? Which damage is prevented? The short answer is the controller of the creature will get to choose which damage is prevented. A slightly longer answer is that the controller of the affected object gets to choose which damage the damage prevention shield will prevent. most of the time, this won’t be very relevant. But if one of the creatures has an ability like deathtouch or lifelink, you may want to prioritize preventing damage from that creature.
Let’s look at an example. I attack with my 6/6 with trample. You (not wanting to take any trample damage) block with a [card]Vampire Nighthawk and a random 4/4. And then I cast Test of Faith on my creature. When it comes time to deal damage, my 6/6 is supposed to receive two damage from the Nighthawk and four damage from the 4/4. If I choose to prevent three damage from the 4/4, then the Nighthawk will deal two damage to my 6/6, my 6/6 will be destroyed due to deathtouch, and you’ll gain 2 life. However, if I choose to prevent two damage from the Nighthawk and one damage from the 4/4, my 6/6 will survive. It won’t take any damage from the deathtouch Nighthawk, and you won’t gain any life, since the damage the Nighthawk would deal is prevented.
Today’s Rules Tip written by Nathan Long