Massive Mass Outbreaks are the new mechanic introduced in Pokémon Legends: Arceus. There is a chance that an area will be infested with a numerous amount of Pokémon. They all have a decent chance to be shiny as well! But, you have to play it a little smart to maximize your time and save on resources required.
As far as we understand it, this is the most efficient way to hunt them for the Pokémon and Shinies you want. This guide will be updated as more information is made available.
Unfortunately, you cannot return to Jubilife to “advance” the state of the game to reset the same outbreaks over and over. Each event is effectively “one-and-done,” so you have to continue checking fresh Massive Mass Outbreaks. To do this, simply enter an area and return to Jubilife Village to attempt to get a new Massive Mass Outbreak.
When it comes to hunting many of them for a shiny, follow the basic steps to get them to spawn in an area and choose your priority of ones to hit wisely. You can either catch them all or fly above them to see if the first four spawns are shiny. It’s up to you if you want to check a few or many of the inner outbreaks. However, choosing priorities allows you to maximize your chance at a rare spawn or Alpha due to the time limit.
Thanks to Anubis (@Sibuna_Switch on Twitter), the shiny rates for Massive Mass Outbreaks have been determined. Check out the original link for more details, but here are the rates based on your conditions. The rates are all based on the Pokémon being in the Massive Mass Outbreak. L10 means research level 10 in the Pokédex, Perfect refers to perfect research level in the Pokédex, and SC means having the shiny charm in your possession.
|L10||Perfect||SC||Shiny Rolls||Shiny Rate|
The outbreaks that are marked with a Star on your map will “advance” to including evolutions and possibly alpha Pokémon as you clear them out. So, to get Alpha shinies from these outbreaks, go after the outbreaks that are marked with stars on your map. Once the mechanics are fully understood, the chances for getting an Alpha outbreak will be updated here.
You can hunt these Alpha Outbreaks individually if you wish to improve your chances. See the next section.
If you stumble upon a rare horde that produces a second wave of spawns (i.e. it says “A new horde is forming” after clearing the initial outbreak), you can do some resetting and fancy combination of events to check more of the spawns. This takes advantage of what is known as “multi-despawn” or “multi-KO”, where the game will produce different Pokémon depending on if it has to generate more than one Pokémon at a time to fill the empty slots. So, here’s the method:
Here’s a table with just a few possible permutations to get unique second wave spawns:
KEY: C is “catch”, KO is “Knock Out.” The colors indicate what to do first, meaning, on row #1, you would KO two at the same time, then catch the rest. But on row #11, you would KO four at the same time then KO three. This extends to the whole table for all different color combinations. If you want to see all possible combinations of events to get unique spawns, check out our tracker tool for the Massive Mass Outbreaks!
Also note that the first outbreak is limited to between eight and ten spawns, so if a row on the table exceeds the eight spawn mark and your outbreak only has eight, then that row is not possible. There are also possiblities for catching in between the KO’s, but that extends the table dramatically.
There are a significant number of possiblities for getting unique spawns., we have a tracker tool for the Massive Mass Outbreaks! It will save your progress and show you all possible combinations.
Several YouTubers have outlined this method, but having a static table on a website is more convenient. Thanks to Austin John Plays and the other Pokémon fans for testing this method out.
The advanced methods can also be extended to Ghost Spawns. See the next section of this page for information on that.
It turns out another method to extend unique spawns has been discovered when there are still Pokémon remaining in an outbreak but no more can spawn in (such as only three remaining of the original eight spawns). If you travel so that the Pokémon are completely out of sight (you can place down a marker on your map and travel away until the marker is about 120 away or fast travel to camp or another close landmark) and return to the outbreak, you will get different results in the second wave.
What happens is that when you leave the area, the game attempts to “fill in” the missing spawns. The RNG advances to try and create the Pokémon, but they’re never “fully” created because there’s no more room for them because the number of spawns has been exhausted. The RNG is still advanced forward, so what happens to the second wave of spawns is completely different.
This is one of the reasons why people lose shinies in the final wave. If you leave the outbreak with fewer than four remaining Pokémon on the field from the first wave you will have different second wave results. Be extremely careful when traveling to camp or leaving the area to avoid aggression especially if you are repeating past actions to get a shiny again.
Again, this guide will be updated as more information is made available!