Slaying monsters is pretty straightforward in a lot of role-playing games. You play as the good guy, and the monsters are usually completely evil. That's certainly not the case in The Witcher. In this upcoming single-player role-playing game based on the works of Polish fantasy novelist Andrzej Sapkowski, you'll play as the antihero Geralt of Rivia, a magically mutated assassin trained from birth to hunt down and slay monsters in a medieval fantasy world where there are no black-and-white decisions. Polish developer CD Projekt hopes to capture the moral ambiguity of Geralt and his world in the game, which will have you making a myriad of tough decisions that will affect the story. To learn more about the game, which is due out in September, we turned to Michal Madej, chief designer of The Witcher.