One - from Prof. Elm. At least, assuming you don't use a Game Shark.
There is, however, a completely harmless glitch that allows you to clone Pokemon - and the items they hold. Give the Master Ball to any Pokemon, go to a PC (a computer), and deposit it in any box. Then select to change the box to any box you want. It will tell you that it needs to save the game (go ahead) but RIGHT AT THE MOMENT it says "Saving, don't turn off the power...", be a rebel and turn off the power.
Then turn it back on and look at your party Pokemon. Oh good, pidgey still has the Master Ball. You breathe a sigh of relief and take it away from him. You log on to the computer, and suddenly, there's another pidgey. And... he also has a Master Ball.You withdraw him, take the Ball from him, and check the Ball Pocket of your pack to make sure. Yep, it's right there... Master Ball x2. Release the other, cloned pidgey, and you've got two Master Balls for the price of one.
Or keep him, and clear out your party pocket monsters. Give both pidgeys the MBs, deposit both of them, switch boxes until it says you shouldn't shut off the power, and be an outlaw once more. Turn it back on, you've got four Master Balls in the arms of your 4 identical pidgeons. You can run a whole factory process, churning out any item you choose, as long as you have one of the item to begin with. I have a good twenty MBs in my pack in case I see something I want but don't have the means to otherwise catch it (I'm always on the lookout for color variations). I also clone for PP ups and the like, but NO Rare Candies - too cheap for my taste.
I also recommend that you also clone a legendary the moment you catch it so that if you ever have a second thought as to how you raised the one you DID train, you don't have to reset the game. They don't lay eggs, so you can't get a second chance otherwise.
This doesn't work with the first three (Red, Blue, or Yellow) since they don't have the little message to not turn off the power when you change boxes. I don't know about the more recent ones above Crystal (Ruby, Saph, and up). It works in Gold, Silver and Crystal for sure. If you want to clone a Yellow, Red, or Blue Version beastie, you can simply trade it to your Silver with the Time Capsule, clone it there, and trade back. Items, however, can't be cloned in those three since in those games, Pokemon can't hold items.
That was rather lengthy, but I think I've answered any questions you could possibly have about cloning in the future. Good luck, and happy cloning!
P.S. I did catch my legendary dogs the othodox way, BTW, with a quick claw, mean looks, hypnosi, false swipes, and Fast Balls. More of a challenge, hunting them down instead of ending my worries with a Cheapster Ball. But Lugia and Ho Oh weren't so lucky ;-) also clone your master ball by giving it to the Pokemon in the sixth slot. then put it in the PC and when your saving turn it off just before the ring. also if you get the whole code same as a Pokemon you will win a master bal in the lottorey. hope this helps:)
Attach your master ball to ONE POKEMON, next CLONE that Pokemon for how many master balls you want. Next detach them, and release all the clones (if you want)
there are 2 master ball s and a master ball is rare you can only use it for kyogre requaza groudon salmence fly gon and the rest of the strongest Pokemon a master ball always captures a Pokemon no Pokemon can break out its in possible
INFINITY MASTERBALLS just do my trick Trade pokemon for pokemon holding masterballs take them away and trade for your pokemon back
professor juniper only gives you one but you can get another one in a Pokemon center somewere
One is given to you by Professor Juniper, near the end of the main plot. The other is given to you by the man who asks how many Pokemon you have traded. He gives you rewards depending on how many you have traded, the reward for trading 50 is a Master Ball. You find him in Castelia City's Pokemon center.
you only get one unless you use a cheat code or its a special event
You can get 2 Master Balls in both versions.
You mainly get one from professor Elm. However, if you get a complete match at the Goldenrod lottery then your prize is a Master Ball.
you can get 1 master ball
1
1
i masterball
one
1 ONLY
You can clone a Pokemon with the master ball or trade it to a friend and keep starting over until you're satisfied with the number of master balls.
There is one you get for playing the game. You can win them in the lottery in the game. Also if you cheat you can have a billion if you really want to.
Attach your master ball to ONE POKEMON, next CLONE that Pokemon for how many master balls you want. Next detach them, and release all the clones (if you want)