This episode of Study for the Bar in Your Car, guided by Angela's notes,, dives into what law federal courts apply, focusing on interactions between state and federal law and the concept of federal common law.

A core principle is the Erie Doctrine, fundamental in diversity cases (citizens of different states). Federal courts in diversity cases must apply state substantive law but follow federal procedural law, including the Federal Rules of Civil Procedure (FRCP). This prevents forum shopping and ensures equitable administration of laws. Federal courts determine state law by following the state's highest court or predicting its ruling if precedent is absent,. The substance/procedure line is complex; state rules, even seemingly procedural, must be applied if they are outcome determinative, significantly affecting the result and encouraging forum shopping. Valid FRCPs generally trump conflicting state procedural rules if within the scope of the Rules Enabling Act and Constitution,. For example, FRCP 23 for class actions usually applies in federal court even if state law prohibits such actions for certain damages,.

The episode details specific areas where state law interacts with federal practice:

• Service of Process: Federal Rule 4 allows plaintiffs to use state law methods for service from the state where the federal court sits or service is made,.
• Personal Jurisdiction: Federal courts often look first to state law via Rule 4(k)(1)(A), applying the state's long-arm statute. However, exercising jurisdiction always requires satisfying the U.S. Constitution's Due Process via sufficient minimum contacts with the forum state.
• Choice of Law: In diversity cases, federal courts apply the choice of law rules of the state where they are located (Klaxon rule) to determine which state's substantive law governs.
• Preclusion: The preclusive effect of a federal diversity judgment is governed by federal common law (Semtek rule). This federal common law typically adopts the preclusion law of the state where the federal court sat, promoting intra-state uniformity,.

The discussion also explains Federal Common Law – judge-made federal law created only where a unique federal interest mandates a uniform national rule, and Congress hasn't acted,,. Examples include disputes between states or federal government contracts. Federal common law can displace state law under the Supremacy Clause but is created reluctantly. This is distinct from Federal Question Jurisdiction, which is the basis for federal court power to hear cases arising under federal law from various sources, including statutes, the Constitution, or federal common law,,. Understanding these concepts is key for the bar exam.

Listen in to understand these vital civil procedure concepts!