School rules help maintain order in a large group of people. School rules also lay the groundwork for adult responsibilities.
There may be anywhere from a few hundred to a few thousand students at any level of education, ranging from elementary school to university. In order for faculty and staff to manage such large groups, implementing rules for the students is necessary. Some rules are intended to protect the students as well as the teachers. Other rules exist to foster a healthy learning and teaching environment.
Rules also help prepare students for life as an adult. By learning to follow rules as a child, a person may be better prepared for following laws as an adult. It also helps the student get used to adhering to policies and procedures that they will face as an employee once they reach adulthood.