The BallLocke variant of the Nuzlocke challenge is played with standard Nuzlocke rules, with one major addition: the player may only catch one Pokémon in each type of Poké Ball. For example, the starter Pokémon comes in a standard Poké Ball, so the player may catch another Pokémon in a Great Ball once they have access to one, then one in an Ultra Ball, and so on. This challenge adds a great degree of limitation to earlier Pokémon games with less types of Poké Balls, but presents an interesting challenge even in later generations.
For a more comprehensive list of additional rules you can use to customize any Nuzlocke run, see our Optional Rules section. For even more unique ways to enjoy the Nuzlocke challenge, check out our Nuzlocke Variants page!