NFL Rulebook
The NFL Rulebook is a guide containing all the rules and regulations governing the game of professional football.
Technically, there are only 18 rules, but each rule is further divided into sections, and many sections are further divided into articles.
The rulebook is periodically updated, with the latest edition being the 2023 NFL Rulebook.
A few examples of the rules are that the NFL games will last for four quarters of 15 minutes each, there will be a 15-minute rest between the second and third quarter (halftime), and goal kicks must be taken anywhere inside the penalty area.
The Commissioner of the league has the authority to decide on the interpretation of these rules, and his ruling is final.