The Lifelocke challenge follows all the main rules of a Nuzlocke, but with a few additions.

  1. If a Pokémon dies, it can be revived if you sacrifice a Pokémon at a nearby level. The sacrificed Pokémon must be within a 3-level radius of the dead Pokémon, and will get released or put in the graveyard instead of the killed Pokémon. If the sacrificed Pokémon is not within a 3-level radius of the killed Pokémon, and you still revive the killed Pokémon, you fail the challenge. You may not sacrifice a Pokémon to save a Pokémon that you sacrificed.
  2. When a Pokémon gets to it's third stage, (Pokémon that don't have a three stage evolution can't get this ability, and mega evolutions don't count.) it gains an extra life, which can be used to revive it if it dies without sacrificing another Pokémon, or it can sacrifice it's extra life to revive a dead Pokémon within the 3-level radius.