Normal Nuzlocke Ruleset:
1. Fainting = Death
2. Only catch Generation IX Pokémon (Species Clause)
3. Nickname Pokémon
Hardcore Nuzlocke Ruleset:
4. No items in battle (held items okay)
5. No leveling past the next Gym Leader/Titan/Star Boss (at the START of the battle) NOTE - this rule was added midway through the change
6. Play on manual "Set" battle mode (RIP)