Possible to compute an algorithim for games?

I was thinking is it possible to make an algorithim, complicated as it is, that would kill mobs on a mmorpg like WoW for you etc, on a PVE server for you, essentially an AI? A basic outline I've considered would be like to find nearest mob (not agressive) alone in a certain area and then an underlying protocol would be if your health was at a critical level it would run away. It is naive but any suggestions? I can't have been the only person to suggest this.