When running a roleplaying game with a group of players, they will often want their characters to specialise in different areas. It’s a bit like a caper movie – you have the one who’s in charge, the one who’s the tech specialist, the one who does the fast-talking con job, the one who handles the physical stuff or who’s a gun expert, etcetera. (A classic form of this would be the A-Team: planner, face man, vehicle driver, physical/tech expert.) In this case, it’s the GM’s job to make sure that all the characters have a chance to show off their skills and get a few neat moments in the limelight. (Well, the GM can’t always make sure that it happens, but she can at least try to make sure that there will be opportunities for doing so in the story/game.)
If one character chooses to declare that she’s a linguist and a specialist in translation, then the GM will no doubt give her a few moments in the limelight where she has to talk to someone whose language nobody else in the group speaks, or translate a vitally important document, or whatever. Which is fair and good. However, the GM can’t make every point in the game hang off her linguistic skills. It would be unfair to all the other players. It would also be unrealistic to force every scenario/campaign to have a vital linguistic component – well, possibly if you’re playing Call of Cthulhu or Bookhounds of London, but otherwise it can feel a bit forced.
The nice thing about being an author rather than a GM is that you don’t have to comply with such a principle.
(rubs hands together)