Gamasutra Reports: "When games are translated, the game companies want to use native speakers of the target language. For example, if you are interested in translating Japanese games into English, it is best if you are a native English speaker. If you are translating English games into German, then German should be your native language. You need to be fluent in the source language, too, and understand slang and idioms.
It's helpful to be familiar with games, of course. This will give you a better understanding of the context you're working in.
If you're interested in a career as a games translator, you need to first figure out the languages in which you will specialize. You will want to get at least a BA in the language you are learning, and the university will probably have courses that deal specifically with translating entertainment. In Europe, there are actually translation and localization programs you can take at a university level that prepare you for a career in translation. Some universities are offering programs that specialize in games translation.
In this career, getting a degree is very important, as it is one way the companies can narrow down qualified applicants."