There are several major areas covered in the case studies of the UPSC Law Optional Subject. These case studies are designed to test the candidate's understanding of various legal principles, their ability to apply these principles to real-life scenarios, and their analytical and reasoning skills. Below are the major areas covered in these case studies:

1. Constitutional Law:
- The case studies in this area focus on the interpretation and application of the Indian Constitution. Candidates are expected to analyze constitutional provisions, landmark judgments, and constitutional amendments.
- Key areas covered include fundamental rights, directive principles of state policy, separation of powers, federalism, and constitutional remedies.

2. Administrative Law:
- Case studies in administrative law deal with the principles and procedures governing administrative agencies and their actions. Candidates are required to analyze administrative decisions, powers and functions of administrative bodies, and judicial review of administrative actions.
- Key areas covered include natural justice, delegated legislation, administrative discretion, and remedies against administrative actions.

3. Criminal Law:
- Case studies in criminal law focus on the interpretation and application of substantive and procedural criminal laws. Candidates are expected to analyze criminal provisions, landmark judgments, and legal principles related to crimes and their punishments.
- Key areas covered include the Indian Penal Code, Criminal Procedure Code, evidence law, and principles of criminal liability.

4. Contract Law:
- Case studies in contract law deal with the formation, performance, and enforcement of contracts. Candidates are required to analyze contractual terms, rights and obligations of parties, and remedies for breach of contract.
- Key areas covered include the Indian Contract Act, specific contracts (such as sale of goods, bailment, and agency), and principles of contractual interpretation.

5. Tort Law:
- Case studies in tort law focus on civil wrongs and the legal remedies available to the victims. Candidates are expected to analyze tortious acts, principles of liability, and defenses against tort claims.
- Key areas covered include negligence, nuisance, defamation, trespass, and strict liability.

6. Family Law:
- Case studies in family law deal with legal issues related to marriage, divorce, adoption, and inheritance. Candidates are required to analyze family disputes, rights and obligations of family members, and legal procedures for resolving family disputes.
- Key areas covered include Hindu Marriage Act, Hindu Succession Act, Special Marriage Act, and principles of family law.

7. Property Law:
- Case studies in property law focus on the rights, duties, and transfer of property. Candidates are expected to analyze legal issues related to ownership, possession, and transfer of property.
- Key areas covered include the Transfer of Property Act, Easements Act, and principles of property law.

8. International Law:
- Case studies in international law deal with legal issues arising from the relations between nations. Candidates are required to analyze international treaties, diplomatic immunity, state responsibility, and dispute resolution mechanisms.
- Key areas covered include international conventions, customary international law, and principles of international human rights law.

By covering these major areas, the case studies in the UPSC Law Optional Subject test the candidate's knowledge and understanding of various branches of law and their ability to apply legal principles to practical situations. It also helps them develop critical thinking and problem-solving skills required for a career in law.