Some companies have people who are hired to manage and create lore for certain franchises. I remember reading an interview with a Lore Director (or something like that) from Blizzard a few years ago, however I can't seem to find it at the moment. I have no idea how you get into that position, I imagine that they are hard to get.
There is no position to just "give ideas for games". Everyone has ideas, which is why there is no real need for that position.
If your friend wants to get into game design, the creative side of it, he should probably take some courses in a field tied to the industry and work his way into a position where he has influence. Also, game journalism seems to be a route into product evaluation, which is closely tied to the creative process.
Are you an ODST (fanboy)?