Which of the following is considered the most significant and formal rules established by the government?

The most significant and formal rules established by the government are typically referred to as law. Laws are formalized rules that are enacted by a governing authority to maintain order, protect individuals, and promote the general welfare of the community. They carry specific consequences for violations and are enforced by various governmental bodies, such as the police and the judiciary.

While regulatory law also involves rules set by governmental agencies to manage specific areas of activity—like environmental protections or workplace safety—these regulations are often derived from broader statutes and are not as foundational as what is encompassed by the term "law" itself. The concept of the rule of law underscores the importance of law in society, emphasizing that laws apply equally to all individuals. Property laws, while crucial, are a subset of the larger body of law. Therefore, law represents the overall framework of rules established by the government, making it the most significant and formal concept among the given options.