Eric Goldman and Roth Cornet of IGN commented on the episode being a "game changer" because it diverges from the book series more than any other "Game of Thrones" episode; a few of the changes include Jon's and Bran's storylines, how Daenerys conquered Meereen, and new information with regard to how White Walkers multiply their army. Goldman and Cornet stated that much of the episode feels like a spoiler for readers of the series because of the changes, including the show creators, who know how the ongoing book series will end, possibly having incorporated aspects that happen later in the books. Though Goldman and Cornet indicated that significantly diverging from the books could be detrimental to the show, they credited "Oathkeeper" with adding an element of surprise and intrigue for all viewers.