Announcement: This is when you will choose the targets of Acolyte’s Reward. The first target (presumably your own creature) will have damage prevented from being dealt to it, and the second target will be the recipient of damage from Acolyte’s Reward. The value of X, and the source of the initial damage, aren’t determined at this point.
Resolution: This is the first, and only, time when your amount of devotion is checked. For example, if your devotion decreases in between announcement and resolution (such as if your opponent plays a removal spell on one of your creatures in response), the value of X, and the amount of damage prevented, will decrease accordingly. This is also the only time when targets are checked. If the first target is illegal, no damage will be prevented. If the second target is illegal, damage can still be prevented, but the second target won’t be dealt any amount of damage by Acolyte’s Reward. Gaining shroud or hexproof later in the turn won’t stop Acolyte’s Reward from affecting these targets.
Damage event: The next amount of damage from any source (up to X) that would be dealt to the first target will be prevented, and Acolyte’s Reward will then immediately deal that amount of damage to the second target. It doesn’t matter what your devotion is at this time, since the value of X was already locked in on resolution.
Today’s Rules Tip written by Jen Wong