Pokémon Legends: Arceus is a big step in many ways for the series because of the way it adjusts the way you encounter and capture Pokémon. Gone are the random encounters and precious wasted time jumping in and out of tall grass hoping to find a specific Pokémon. One new inclusion added to the game is Mass Outbreaks. Here is what you need to know about them.
In Pokémon Legends: Arceus, Mass Outbreaks are a new world event that will spawn a bunch of a particular Pokémon species in an area. These only unlock once you have completed the main story, so they will be imperative to completing your Hisuian Pokédex and will be the best method for hunting shinies in the post-game.
Mass Outbreaks will routinely pop up on the map as you travel between areas, so if you want to reset them, just travel back and forth to reroll the outbreak. When you enter the zone, the Mass Outbreak will not end for as long as you are hunting Pokémon. If you are specifically looking for shinies, we recommend saving before stepping in so you can reload your file if no shinies appear. If you do see a shiny, save again to give yourself multiple chances to catch it.