Laws of the Game

“The Laws of the Game are the codified rules of association football. The laws mention the number of players a team should have, the game length, the size of the field and ball, the type and nature of fouls that referees may penalise, the offside law, and many other laws that define the sport. During a match, it is the task of the referee to interpret and enforce the Laws of the Game. There were various attempts to codify rules among the various types of football in the mid-19th century. The extant Laws date back to 1863 where a ruleset was formally adopted by the newly formed Football Association (FA) and written by its first secretary, Ebenezer Cobb Morley. Over time, the Laws have been amended, and since 1886 they have been maintained by the International Football Association Board (IFAB). The Laws are the only rules of association football FIFA permits its members to use. …”
Wikipedia
History of Association Football