Enchantment, 2WWW (5)
Rare
At the beginning of your upkeep, if you have exactly 1 life, you win the game.
Lands ravaged, cities in ruins, so many lives sacrificed, and yet there was no other word for it but victory.
Illus. Dan Scott

6/15/2010: This ability has an "intervening 'if' clause." That means (1) the ability triggers only if you have exactly 1 life as your upkeep begins, and (2) the ability does nothing if your life total is anything other than 1 by the time it resolves.
6/15/2010: In a Two-Headed Giant game, anything that cares about your life total checks your team's life total. (This is a change from previous rules.) You'll win the game if your team has exactly 1 life.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern