Firstly, you've got to play the game. Knowing the product and its mechanics is crucial; you won't get a call-back without it. Being a volunteer for a time gives you bonus points towards a call-back, as does attending FanFest and being sociable with the employees, and the employees do love to party during FanFest. The interview is less an interview and more an explanation of what would be required of you; if you don't put yourself forward and show off what you know and what you're capable of, you won't be called back afterwards. For CS/Game Master positions, there's an English test (it's written by an Icelander, though, so some of the test itself is wrong). After that, either you get a call back or they'll email you to say you're not what they're looking for. CCP is one of the few companies that WILL let you know you haven't made the cut, and the longer they take to respond, the better the chance you'll be hired.

They give you a test to make sure your English level and ask something like why you left your previous job