Actually, legally you don't have the right to use in-game music. Actually, you don't "own" even the game at all. You purchase a license to play it, that's all.
Theoretically, you can be forced to take down from any site videos or mods containing copyrighted material, such as game music.
However, in the cases you mentioned, usually the copyright holders tolerate your use of the music, as long as there is no profit involved and they get credited. (Inon Zur for the composition, Bioware/EA for the copyright) But it's them turning a blind eye, not your right.
For higher profile things, like, for example, a fan movie that might get shown on a festival, it's very advisable (and polite) to contact the copyright holder, explain what you want to do, and that there is no profit involved, and ask for permission to use the music for that purpose.
Heck, it's always polite to ask the artist first, anyway. After all, it's his creation.
The alternative (which doesn't exactly apply to your case) is to ask an aspiring composer (like me

) if he would like to contribute some music for your project. You are doing this work for fun, so why shouldn't he...
Bearbeitet von Marvin_Arnold, 28 Mai 2011 - 10:47 .