In a federal diversity case, which law applies to substantive rights?

In a federal diversity case, which law applies to substantive rights?

• A. State substantive law.
• B. Federal procedural law.
• C. Constitutional principles only.
• D. Both state and federal substantive law.

Answer: (D)

In diversity cases, the governing rules for substantive rights come from the state, not a mix of federal and state. This follows the Erie doctrine: when a federal court sits in diversity, it must apply the state’s substantive law to determine what rights and remedies the parties have. Substantive rights include the elements of the claim, defenses, and statutes of limitations. The federal system handles the case’s mechanics using federal procedure (the Federal Rules of Civil Procedure, evidence rules, etc.). Constitutional principles set federal limits, but they don’t replace state substantive law for private rights in a diversity dispute. So the substantive rights are decided by state substantive law, while the process of litigating the case stays under federal procedural rules.

In diversity cases, the governing rules for substantive rights come from the state, not a mix of federal and state. This follows the Erie doctrine: when a federal court sits in diversity, it must apply the state’s substantive law to determine what rights and remedies the parties have. Substantive rights include the elements of the claim, defenses, and statutes of limitations. The federal system handles the case’s mechanics using federal procedure (the Federal Rules of Civil Procedure, evidence rules, etc.). Constitutional principles set federal limits, but they don’t replace state substantive law for private rights in a diversity dispute. So the substantive rights are decided by state substantive law, while the process of litigating the case stays under federal procedural rules.