Crappy Jack posted:

Along the same lines, katanas being a thing in GoT is a pretty huge historical leap as well; it'd be like having somebody with a pump-action shotgun in the Revolutionary War. It's believed that katanas were actually invented as a response to the Mongol Invasions; Japanese weapons of the time tended to break against Mongolian armor.

At the same time, the game's trying to be a Fun Samurai Game more than a historically accurate simulation, but it's worth bearing in mind they're playing REALLY fast and loose with history in this game.