What rules of substantive law will the courts use?

Courts apply substantive law rules to determine the rights and obligations of the parties involved in a case. These rules may include statutes, case law, and regulations that govern specific areas such as contracts, torts, property, and criminal law. The court interprets these laws to resolve disputes, establish liability, and determine remedies. Ultimately, the application of substantive law helps ensure justice is served based on established legal principles.