: You can only catch the first Pokémon you encounter in each unique area (defined by its subtitle).

The concept surfaced in late 2017, shortly after Ultra Sun and Moon launched. The idea was a that baked Nuzlocke rules directly into the game’s code:

Randomizes wild encounters, trainer teams, movesets, abilities, and even Pokémon typings. Custom Textures: Features "re-skinned" or "corrupted" Pokémon, such as Shadow Mewtwo Crystal Onix Totoro Snorlax Hardcore Rules:

The real search begins when people try to find a that enforces these rules automatically.