Well, any game can be role played. Shadowbane: Throne of Oblivion is a hardcore PvPvE game that a friend and I role play on quite often. JKA? My favorite game to role play on because it is easy to role play on.
Now, Kouen, programming is not at all hard if you have the talent for it. The difficulty depends on how well the original program was programmed and for what intent. To add roleplay capabilities will be a pain for the end user, but the functions themselves are relatively easy. Robophred made a mod called Euka (discontinued until he gets more time to finish it) that gives the player the ultimate role playing system, like, better than a game made for role playing. it took him 6 months. He is professional. Yea, it can be done. Depends on the code and programmer's imagination.
TheDestroyer, founder of the New Masters Of Order.