Short answer: You don't.
Win the lottery at Jubilife city.
no you cant they hatch in pokeballs
Action Replay (AR) you get 999 of them
there is no more masterballs in Pokemon platinum but not if you use cheats
be more specific in your question
Go to the department store and mach all of the numbers or cheat for them.
just make a Pokemon hold a master ball and trade it.....if you have the patience to do that over and over that is.
You trade 50 peolple and talk to a spy in Pokemon center castelia city
One masterball is in Pokemon emerald. To find out more go to my site called www.miquel.ning.com
You can't get more masterballs because in the game they give you 1 master to catch that games legendary. (e.g) In Pokemon soul silver Professer Elm gives you one masterball to catch Lugia or any other Pokemon.
Ruby, Sapphire and Emerald version can get multiple masterballs from winning the grand prize from the lottery in lilycove city which is in the dept store in order to win the numbers on the ticket must match all the digits of your pokemon's ID number.
you throw away masterballs so u have the number of the Pokemon.say u want kangaskhan.u throw away 378 masterballs to get 115.don't worry about the ultraballs cause they are for the level and i does not work.you hit L in the grass to get the Pokemon and if you want arceus you just hit L.to get more masterballs hitL+R.