>The key to using the Masuda method is not to breed any two Pokémon, but to breed two Pokémon created in games of different countries. An Egg resulting from such a pairing will have a higher likelihood of being Shiny. The most common way to arrange such a pairing is to use one foreign Pokémon and one from the game in which the breeding occurs, although the method will work in any game provided at least one of the Pokémon in the pair is from a country different to the country of the game cartridge.
They must be foreign to the cartridge. The compatibility is determined from 2 games that were bought in 2 different countries.
>I was wondering if it's determined by language? So say I get a US game and a UK game, for all intents and purposes, the Pokemon caught in those two games do not count as being from different countries, and only games with different languages count.
It is determined by language. That wouldn't work.
>If I get the English or Chinese version in Hong Kong, will that count as different from the UK game? Or is it that only the Chinese version will count, due to language? (Actually I'm not too sure if there's even a Chinese version; I don't think they bothered with it & it's just in English.)
I don't get what you mean by Chinese is different or not, but a Pokemon traded from a game that is bought in China will work.
If you are thinking that buying an English version of the game in China and saying it will work, then no. There is an internal marker on each Pokemon that tracks its home location.