Initially, Atreus was not going to be related to Kratos, and his parentage was going to be the driving mystery. Only after presenting early test footage was the idea of Kratos being his father introduced and implemented.

While working at LucasArts, Director Cory Barlog was allowed to read the script for the canceled Star Wars live-action TV series. He was blown away by how much the story made him care about the series ongoing villain, Palpatine, and he used this as inspiration for Kratos's character in the story.

During early development, there was talk about having a different protagonist for the game, but it was decided to keep Kratos. Referencing the Nintendo character Mario and the Mario games, Director Cory Barlog said that just like Mario, "Kratos is intrinsically tied" to the God of War series.

Before deciding on Norse mythology, Egyptian mythology was considered, but was rejected because the team wanted the focus to stay on Kratos

Game director Cory Barlow stated in an interview that naming the game "God of War" without a numeral or subtitle was deliberate because of the series' transition to Norse mythology. He additionally stated that although the game is the sequel to God of War III, "we are re-imagining everything".