Instant, (Color Indicator: White)
Rare
The next time a source of your choice would deal damage to you this turn, prevent that damage. You gain life equal to the damage prevented this way.
At the beginning of your next upkeep, pay {1}{W}{W}. If you don't, you lose the game.
Illus. Dave Kendall

5/1/2007: The delayed triggered ability will trigger regardless of whether any damage is actually prevented.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern