As the 2012 IJHS article “On Bosworth Field or the Playing Fields of Eton and Rugby? Who Really Invented Modern Football?,” by Peter Swain and Adrian Harvey shows, in the early years of the game rules had not been standardized across Britain.

A question that came up was how the rules (traditionally called “laws”) have evolved.

This article at the FIFA website gives you a quick summary of their evolution since the middle of the 19th century: The Laws: From 1863 to the Present Day, at FIFA Classic.