You need to have a korean Social Security # in order to access the Korean Servers.
I know that people have "obtained them" but from what I've heard there could be penalties.
Here is a post from a community manager working on another korean game:
Hey Guys,
So I think the time has come to just make this statement: Please do not try to play the korean client using an illegal korean social security number! Depending on the country the punishment for this is increasingly severe!
No, you can't, unless you have a Korean Identification number (national ID number.) Similarly, you may not log onto the Chinese servers, as access to, and special controls for, those servers are subject to Chinese government rules.
But even without such restrictions, why would you wish to? The distance lag would be horrendeous, and the game will be in a language other than English. Clans would be active at a time you would be sleeping or working; similarly for Manor and Seige times.
1) Maybe get an early look at c5
2) See what a farmer on our server feels like, with so many of them out there it has to be somewhat amusing when 99.9% of the population of the server cant communicate with you. Farmers seem to love it.