The battle of the open world formats, where players can roam as fictionalized American cities or a fictionalized Western US and Mexican frontier. In both games, each player can choose and complete a series of missions to complete the game. And, in each there is a “morality” factor where respect and “honor” are gained or lost based on the players actions in the game.
The main difference here is do you want to travel by horse or horsepower…oh, and maybe how you define moral .
Grand Theft Auto: http://en.wikipedia.org/wiki/Grand_Theft_Auto_(series)
Red Dead Redemption: http://en.wikipedia.org/wiki/Red_Dead_Redemption
