Complex NPC routines you can meddle with to your hero’s content? Playground’s got ‘em.This is an IGN opinion piece from writer Jeremy Peel, who has followed Fable since the Lionhead days, and is forever midway through playthroughs of Oblivion and Fallout: New Vegas.There’s a moment in Fable’s latest gameplay demo, right after the hero saves a talking pig from being butchered and …