There are two games that really kicked off what we think of as the modern “open world” game: Super Mario 64 and Grand Theft Auto III. These games unshackled the player from linear progression through a game’s levels. I think Shadow of Mordor is the first “open narrative” game. You’re not just checking off missions in a variable sequence. You’re changing the dramatis personae. Whenever you succeed or fail, the characters in the story respond to your actions, and not in the manner of a branching “choose your own adventure.” It is an excessively simple, yet impressively flexible, crime story.