How were the rules decided?

Answer 1

Well ... gradually over the years when new kings and queens didn't like something or they didn't want it they often made rules to ban them or get rid of the.

This really depends on what rules you're talking about. Rules can refer to laws governing a nation or other entity. They can refer to the manner in which a game is played. They can refer to many other things. By specifying exactly which rules you are talking about, the Wiki Answers community can provide a more adequate answer.