The complication comes from confusion about the interaction of replacement and/or prevention effects. The comprehensive rules say this: “If two or more replacement and/or prevention effects are attempting to modify the way an event affects an object or player, the affected object’s controller (or its owner if it has no controller) or the affected player chooses one to apply.”
Ok, so, what does that mean?
Let’s say I control Gisela and I’m attacking you with her. You cast Divine Deflection with X=4 targeting me. When combat damage would be dealt, we have two effects attempting to modify that damage event. My Gisela says “double that damage” and your Deflection says “prevent that damage.” The key point here is that who controls which effect is completely irrelevant. For all intents and purposes, replacement/prevention effects have no controller. So who gets to choose as the “affected player”?
The affected player is the one that the event would be happening to. Since damage is being dealt to you, you’re the affected player. Now, how does that matter? You get to choose the order to apply the effects. After the first is applied, you apply the next if it’s still applicable, and so on, as follows:
- The basic event is “Gisela deals 5 damage to you.”
- You apply Divine Deflection first (because you’re a good player). This changes the event to “Gisela deals 1 damage to you.”
- Then you check and see that Gisela’s ability is still relevant, and you apply it so the event becomes “Gisela deals 2 damage to you.”
Divine Deflection is a little unusual, because it’s not actually a redirection effect. The damage is prevented just before it deals an equal amount of damage to whatever you originally targeted (note that this is still part of the prevention effect, and does not use the stack; it just happens immediately after the prevention). So after the 4 damage is prevented, it attempts to deal 4 damage to me. Now, Gisela’s ability applies for me because I’m the “affected player” for this damage event, and the event is modified from “Divine Deflection deals 4 damage to me” to “Divine Deflection deals 2 damage to me.”
If you applied the effects in the opposite order, you could choose to first double the damage with Gisela’s effect, then prevent 4 damage, but this results in a final damage event of “Gisela deals 6 damage to you.” followed by “Divine Deflection deals 2 damage to me.” So unless you really want to lose 4 extra life, you should probably apply them in the first order.
Today’s (exceptionally long) Rules Tip written by
Josh Stansfield, Level 2 judge from Orange, CA