While one Master Ball can be received in "Pok?mon: Leaf Green" by talking to the president of Sliph.co after defeating Giovanni, there are other methods to help players get more Master Balls. Legitimately, players can gain extra Master Balls by entering Lucky Channel drawings or entering the daily raffle at a raffle shop. Players can also gain more than one Master Ball through external devices like Game Shark.
In "Pok?mon: Leaf Green," players can tune in to channel 8.5 through their Pok?gear and listen every Friday. Each Friday, a random Trainer ID number is read out. If the number directly matches a player's own Trainer ID number, they will be awarded a Master ball. Players can also try their luck at a raffle shop every day; however, the chances to get a Master Ball are exceptionally low. Through the use of an external third-party cheat cartridge like a Game Shark, players can also use codes to spawn in more Master Balls. If players desperately need Master Balls, it is possible to find them in other Pok?mon games and then trade them to a copy of "Leaf Green"; however, to do this, two different copies of Pok?mon are needed, as well as two devices.