http://www.pcgamer.com/ubisoft-explains-why-assassins-creed-origins-has-adjustable-difficulty/

"For better or worse," we said last week, "Assassin's Creed: Origins is an RPG now." That shifting aspect of the game is reflected in a number of different ways, not least of them the addition of a difficulty setting, a first for the series. The idea, game director Ashraf Ismail told GamesRadar, is to ensure that while Origins' gameplay is "deeper" than previous games in the series, it still remains accessible to everyone. 

"We wanted more gameplay depth, and that means more challenging aspects of the game—bosses, and so on," he said. "What we felt was, by going deeper into the gameplay challenge of the game, we're feeding one part of the audience but not others. So it was a natural step for us to think well, let's give difficulty settings so that if you're really more into the narrative or the historical element, you can set the game to an easier setting."