The Master Ball is one of the most iconic and powerful items in the Pokemon series, and Pokemon Legends: Z-A is no exception. Known for its perfect catch rate—guaranteeing success on any Pokemon—it's a tool best reserved for rare, one-of-a-kind encounters. While you can't expect to find dozens of them, there are clear ways to earn and even purchase one if you know where to look.

The Master Ball in Pokemon Legends: Z-A is earned through Mable's Research, a progression system unlocked early in the story. You'll first encounter Mable during Main Mission 03: A New Life in Lumiose City, which introduces you to the Pokemon Research Center and her unique point-based research system.
Once the mission is complete, you gain access to the Research interface. This system rewards you with items, including TMs and rare materials, as you earn Research Points and level up your rank.
To receive the Master Ball, you must reach Level 49—a significant milestone that requires completing dozens of tasks and accumulating thousands of points. Once you reach that level, you can simply open the Research Menu and press X to claim your reward; you don't have to return to Mable in person.
Points come from completing various Requests and tallies. These include:
Reaching Rank 49 will take considerable time, but it's worth the grind if you want this ultimate item legitimately.
If you prefer a faster route, players can also buy Master Balls through U4GM. For example, U4GM offers 10× Master Balls for $5.99, with instant delivery. This option is convenient for players who don't want to spend hours grinding or who want extras for multiple rare catches—especially for events, Shinies, or Alpha Pokemon.
While purists may prefer earning it through gameplay, having an extra supply of Master Balls ensures you'll never lose a once-in-a-lifetime Pokemon encounter.
The Master Ball's guaranteed capture means it should be reserved for Pokemon that are either:
In Pokemon Legends: Z-A, most Legendary Pokemon can be reliably caught with Ultra Balls after multiple attempts, so you might consider saving your Master Ball for a particularly special find—like a Shiny Starter or a one-off Alpha encounter.
To summarize:
With patience—or the right investment—you'll be holding one of the rarest items in Pokemon Legends: Z-A, ready for your next big catch.