Typically, when you go to an area, once you've mined it for its interactable Pokémon and items, it is useless, the Hidden Grotto is different. The contents of the Hidden Grottos change and get regenerated repeatedly.Whenever you take 256 steps in the game, there is a 5% chance that each of the Hidden Grottos will be regenerated. When it's regenerated, there's a 40% chance of an item, a 40% chance of a hidden item and a 20% chance of a Pokémon. The chance that it regenerates can be increased using a Pass Power.
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