Black-letter propositions
- 01
A valid federal constitutional provision, statute, or Federal Rule on point controls if it is valid and directly conflicts with state law.
- 02
Without controlling federal law, consider outcome effect, discouraging forum shopping, avoiding inequitable administration, and countervailing federal interests.
- 03
State statutes of limitations, claim elements, burdens tied to substance, and choice-of-law rules are ordinarily substantive.
- 04
Judge-made federal common law is limited to enclaves of uniquely federal interest.
Use this attack sequence under time
Frame the issue
Identify the source of federal authority.
Resolve the next checkpoint
Ask whether federal and state rules directly collide.
Resolve the next checkpoint
If no collision, perform the modified outcome-determinative analysis.
Finish the conclusion
State the chosen law and why.
Common wrong turns
- The label procedural or substantive is a conclusion, not the analysis.
- A federal court does not create general federal common law.
- A transfer ordinarily preserves the transferor state's choice-of-law rules, but an enforced forum-selection clause can alter that consequence.
Worked example
A diversity case is timely under a federal judge-made practice but barred by the forum state's limitations statute.
The state limitations rule ordinarily applies because limitations can determine the result, drive forum shopping, and produce inequitable administration; no valid conflicting Federal Rule has been identified.
Practice this topic
The statutory sources
The Rules of Decision Act, 28 U.S.C. 1652, says the laws of the several states, except where the Constitution, treaties or Acts of Congress otherwise require or provide, shall be regarded as rules of decision in civil actions in federal courts in cases where they apply. The Rules Enabling Act, 28 U.S.C. 2072, gives the Supreme Court power to prescribe general rules of practice and procedure, and says the rules shall not abridge, enlarge or modify any substantive right.
Cornell's summary states the doctrine as requiring federal courts exercising diversity jurisdiction to apply state substantive law and federal procedural law. It notes that before Erie Railroad v. Tompkins federal courts followed Swift v. Tyson and applied general common law.
How to sort a conflict
When a Federal Rule of Civil Procedure covers the point in dispute, the Rules Enabling Act's limit on substantive rights is the first question. When no federal rule applies, the Rules of Decision Act sends the court to state law where it applies. The two statutes answer different questions, so identify which one the fact pattern presents.
The time to serve an answer is set by Rule 12(a) and is procedural, while the source of a substantive right in a diversity case comes from state law.
Frequently asked questions
What is the controlling rule for erie, federal common law, and conflicts?+
Under Erie, valid controlling federal law governs procedure; otherwise the federal court applies forum-state substantive law and its conflicts rules.
What does the Rules of Decision Act say?+
State laws are rules of decision in civil actions in federal courts in cases where they apply, except where the Constitution, treaties or Acts of Congress otherwise require or provide.
What limit does the Rules Enabling Act place on federal rules?+
Rules of practice and procedure shall not abridge, enlarge or modify any substantive right, according to 28 U.S.C. 2072(b).
What did Erie change?+
Federal courts exercising diversity jurisdiction must apply state substantive law and federal procedural law, and Erie overruled Swift v. Tyson's general common law approach.
What governed federal courts before Erie?+
Swift v. Tyson, which read the laws of the several states to include only state statutes and local customs, not state judicial decisions, per Cornell's summary.
Which statute sends federal courts to state law?+
The Rules of Decision Act, 28 U.S.C. 1652, which applies where the Constitution, treaties or Acts of Congress do not otherwise require or provide.