Update 1.1 to Pokemon Legends: Arceus, also known as Daybreak, brought several new features to the game. Two new battling gauntlets were added to give players more reasons to keep coming back, but perhaps the most significant addition was that of massive mass outbreaks.

As their name suggests, these special events are even bigger versions of the mass outbreaks that have been in the game since launch and feature around 15 separate outbreaks of Pokemon within an area of the Hisui region. Tackling something of this magnitude can be a daunting prospect, but this guide will have everything you need to know to get the most out of the new massive mass outbreaks.

Updated December 14, 2023, by Sean Murray: If you're still looking for how to unlock massive mass outbreaks in the Daybreak update, we've got you covered in this refreshed guide. We've improved this guide's formatting and added more breakout tips to make unlocking, finding, and running these outbreaks easier than ever. You can even use these outbreaks to help find a shiny Pokemon in Pokemon Legends: Arceus.

What Are Massive Mass Outbreaks?

While a regular mass outbreak will cause a singular instance of a species of Pokemon spawning at four at a time (up to a total of 16), massive mass outbreaks cause several of these spawning hordes — typically 15 or so — all across the map of the area you're in.

Furthermore, when you finish up with a given Pokemon's horde, there is a chance for another second horde of Pokemon to spawn. These can be another wave of the first species, evolved forms of the first species, or even Alpha Pokemon.

Like their non-massive counterparts, massive mass outbreaks have increased shiny odds, although not to the extent of regular mass outbreaks. While regular mass outbreaks offer a whopping 25 extra shiny rolls, massive mass outbreaks are around half that, with 12 extra rolls.

Here's a table of the various combinations of odds, so you can work out exactly what your chances are.

For comparison, regular mass outbreaks' odds top out at around 1 in 128, so while massive mass outbreaks are lower, the difference isn't huge.

Furthermore, you can see far more Pokemon in a massive mass outbreak to compensate for the difference in odds, and the chance at a sweet shiny alpha more than makes up for it anyway.

How To Unlock Massive Mass Outbreaks

Unlike regular mass outbreaks, massive mass outbreaks won't just start spawning on their own. You need to complete a (rather lengthy) quest to unlock them, which you can trigger by speaking to Mai in the Obsidian Fieldlands. This will activate a series of quests where you investigate massive mass outbreaks in all five of the game's areas.

For each massive mass outbreak, you'll be tasked with clearing out any three of the hordes they contain (either by catching or knocking out the Pokemon). Do this and return to Mai, and you'll move on to the next area to repeat the process, gathering more information about the phenomenon each time you do so.

Once the questline is complete, massive mass outbreaks will begin to spawn randomly within your game, just like regular mass outbreaks do.

How To Complete Massive Mass Outbreaks

Massive mass outbreaks generate the same way regular mass outbreaks do, having a chance to spawn whenever you travel to Jubilife.

They're fairly common, so you should have no real difficulty finding one, but if one isn't appearing, you can just head out to an area and return to re-roll the spawns.

Massive mass outbreaks can be identified by a question mark symbol over an area of the Hisui region, visible when you go to leave Jubilife Village. Once you travel to the area with the massive mass outbreak, you can open your map to see the locations of all the individual Pokemon hordes.

However, the species of Pokemon are hidden, and instead, you just see question marks. Fortunately, this can be fixed by giving Mai's Munchlax five Aguav Berries, at which point all the species of Pokemon in the massive mass outbreak will be revealed.

How Long Do Massive Mass Outbreaks Last?

If you travel to the area with the symbol, you'll notice rain (or snow, in the case of the Alabaster Icelands). This is how you keep track of the massive mass outbreak, as, unlike regular mass outbreaks, massive mass outbreaks operate on a hidden timer.

As long as it's raining, the massive mass outbreak will continue, but once the rain stops, the Pokemon will be gone. You'll see various messages appear on-screen during the massive mass outbreak to give you an idea of how long you have left.

You won't have time to clear out every horde within the massive mass outbreak, so prioritizing is important — decide what species you're most interested in, or if you're hunting a specific alpha or shiny, and head there first.

There is no exact set amount of time the massive mass outbreak will last. If you're seeing, "The rainstorm shows no signs of stopping anytime soon," then you have nothing to worry about. Once you see, "The rainstorm may go on a bit longer," followed by, "The rainstorm seems like it's about to clear up," then you know the massive mass outbreak is coming to an end.

Massive Mass Outbreak Icons

While any horde within the massive mass outbreak has a chance of causing the aforementioned second wave to spawn, some are guaranteed to have this effect.

These hordes can be identified via a sparkle icon on the Pokemon's icon once you've fed the Munchlax, allowing you to identify where to head first for the best chance at a cool second wave.

The other type of icon you need to know about is the berry, which means you can be rewarded with Aguav Berries for clearing out the hordes it appears on. This is a great way to recoup the Berries you spent on revealing the hordes. If you plan on doing a lot of massive mass outbreaks, be sure to stop by a few Pokemon with berry icons to keep Aguav supplies nice and high.

How To Shiny Hunt With Massive Mass Outbreaks

Massive mass outbreaks are seeded, meaning that, if you were to save before traveling to the massive mass outbreak, go and catch as much as you can, then load the save and try again, you'd see the exact same (presumably non-shiny) Pokemon, meaning this isn't a viable way to shiny hunt.

However, the flip side of this is that if you do find a shiny, it would still be there if you were to reload the save.

This means you don't have to worry about failing it. You can reload if you find a shiny late in the outbreak and beeline straight for it on the next attempt, giving you more time to see more of the massive mass outbreak you didn't cover last time.

The one (sort of) exception to the rule on seeding is the secondary hordes. If you're at a horde marked with a sparkle on the map, you can preemptively hunt the subsequent second horde. This second horde's seed is determined by how you deal with the first horde.

Saving before clearing it out and trying different combinations of catching and knocking out will allow you to see different secondary horde Pokemon each time, giving you the best chance of seeing a shiny.