In the aftermath of Judgment Day, we fled to the Exclusion Zone and sought refuge underground. This is what is left of our fallen civilization.

How to play Shogi (Japanese Chess)

A key rule in shogi is the ability to capture an opponent's piece and then play that piece onto the board as one's own piece. This reminds me of how humans were able to survive the AI wars by capturing and reprogramming enemy machines to fight alongside flesh and blood soldiers.