Where are there masterballs in Pokemon emerald?

Answer 1

In Ruby, Sapphire, and Emerald, Master Balls can be obtained in two ways.

First, there is a Master Ball hidden in Team Aqua's Hideout (Team Magma's Hideout in Ruby). There are four Balls in one of the rooms. The two balls further to the right are wild Electrodes. The two balls to the left actually hold items. One contains a Nugget, and the other contains the Master Ball.

Second, additional Master Balls can be won from the Lottery Corner in the Mossdeep Department Store. If the Lotto number drawn matches the digits of one of your Pokemon's OT number exactly, you will receive a free Master Ball. Having Pokemon that originally belonged to different trainers will make winning the Master Ball more likely. If your game's internal battery has not run dry (the game will tell you if it is every time you start it up), you will be able to draw a new Lotto Number every day.

One last note: in Emerald, there is a way to clone Pokemon and items without a cheating device. This could be used to clone a Master Ball (if you already have one, of course).