The Erie Doctrine and Choice of Law

California Bar Exam Exam

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1 Exam Format and Core Skills

California Bar Exam Blueprint: Subjects, Components, and Recent Changes Exam Format, Scoring, and the 1390 Passing Score Essay Strategy: Issue Spotting and IRAC Core Written Skills and Timing Strategy

2 Civil Procedure

Subject Matter Jurisdiction: Federal Question, Diversity, Supplemental, Removal Personal Jurisdiction, Long-Arm, Minimum Contacts, and Service of Process Venue, Transfer, and Forum Non Conveniens The Erie Doctrine and Choice of Law Pleadings, Rule 11, Amendments, and California Demurrers / Anti-SLAPP Joinder of Claims and Parties, Impleader, Intervention, Interpleader Class Actions (Rule 23 and California) Discovery: Scope, Devices, Privilege, and Sanctions Pretrial Adjudication: Dismissals, Default, and Summary Judgment Trial, Jury, Judgment as a Matter of Law, and Post-Trial Motions Appeals, the Final Judgment Rule, and Claim/Issue Preclusion

3 Constitutional Law

Judicial Review, Justiciability, Standing, Ripeness, Mootness, and Political Questions Federal Legislative Power: Commerce, Taxing & Spending, and the Tenth and Eleventh Amendments Separation of Powers: Executive, Legislative, and Judicial Authority Federalism, Supremacy, Preemption, the Dormant Commerce Clause, and Privileges & Immunities State Action and Congressional Enforcement of the Reconstruction Amendments Procedural Due Process Substantive Due Process and Fundamental Rights Equal Protection and Levels of Scrutiny First Amendment: Speech, Press, Forums, and Association First Amendment Religion Clauses and the Takings Clause

4 Contracts

Applicable Law: Common Law vs. UCC Article 2 and Mixed Contracts Mutual Assent: Offer, Acceptance, Mailbox Rule, and UCC 2-207 Consideration, Bargained-for Exchange, and Promissory Estoppel Defenses to Formation: Capacity, Mistake, Misrepresentation, Duress, Unconscionability The Statute of Frauds Parol Evidence Rule and Contract Interpretation Conditions and Performance: Express, Constructive, and Substantial Performance Breach, Anticipatory Repudiation, and the Perfect Tender Rule Excuse of Performance: Impossibility, Impracticability, and Frustration UCC Warranties and Risk of Loss Third-Party Beneficiaries, Assignment, and Delegation Contract Remedies and UCC Buyer/Seller Remedies

5 Criminal Law and Procedure

Actus Reus, Mens Rea, Concurrence, and Causation Accomplice Liability and Parties to Crime Inchoate Crimes: Attempt, Conspiracy, and Solicitation Homicide: Murder, Manslaughter, Felony Murder, and California Degrees Other Crimes Against the Person: Assault, Battery, Kidnapping, and Sex Offenses Property and Theft Crimes: Larceny, Embezzlement, Robbery, Burglary, Arson Criminal Defenses: Insanity, Intoxication, Self-Defense, Duress, Necessity, Mistake Fourth Amendment: Searches, Seizures, Warrants, and Exceptions The Exclusionary Rule, Standing, and Fruit of the Poisonous Tree Fifth Amendment: Miranda, Self-Incrimination, and Double Jeopardy Sixth Amendment: Right to Counsel, Confrontation, Speedy Trial, and Jury Pretrial Identifications, the Eighth Amendment, and Trial Rights

6 Evidence

Relevance: Logical and Legal, Rule 403, and California Proposition 8 Policy-Based Exclusions: Subsequent Remedial Measures, Settlements, Insurance, Pleas Authentication and the Best Evidence Rule Witness Competency, Personal Knowledge, and Examination Impeachment of Witnesses Lay and Expert Opinion Testimony (Daubert and California Kelly/Sargon) Character Evidence and Other Acts (MIMIC) Habit and Methods of Proving Character Hearsay: Definition, Non-Hearsay, and Exemptions Hearsay Exceptions: Availability Immaterial (FRE 803) Hearsay Exceptions Requiring Unavailability (FRE 804) and the Confrontation Clause Privileges, Judicial Notice, and Presumptions (Federal and California)

7 Real Property

1.1 Estates in Land 1.2 Future Interests 1.3 Rule Against Perpetuities 1.4 Concurrent Ownership 1.5 Landlord-Tenant Law 1.6 Easements and Servitudes 1.7 Covenants Running with Land 1.8 Recording Acts and Title 1.9 Mortgages 1.10 Land Use Regulation Adverse Possession and Rights Incident to Ownership Land Sale Contracts, Marketable Title, and Risk of Loss Deeds, Delivery, Warranties of Title, and Fixtures

8 Torts

Intentional Torts Against the Person: Battery, Assault, False Imprisonment, IIED Intentional Torts to Property and Defenses/Privileges Negligence: Duty and the Standard of Care Negligence: Breach, Res Ipsa Loquitur, and Negligence Per Se Causation: Actual and Proximate Cause Negligence Damages and Defenses: Comparative Fault and Assumption of Risk Strict Liability: Animals and Abnormally Dangerous Activities Products Liability Private and Public Nuisance Defamation Invasion of Privacy, Misrepresentation, and Economic Torts Vicarious Liability, Joint Tortfeasors, and Immunities

9 Business Associations

Agency: Formation, Actual and Apparent Authority, and Ratification Agency: Principal/Agent Duties, Respondeat Superior, and Tort Liability General Partnerships: Formation, Rights, and Partnership Property Partnership Liability, Fiduciary Duties, Dissociation, and Dissolution Limited Partnerships, LLPs, and LLCs Corporations: Formation, Promoters, and Piercing the Corporate Veil Corporate Finance: Stock, Securities, Dividends, and Distributions Directors and Officers: Fiduciary Duties, the Business Judgment Rule, and Indemnification Shareholders, Derivative Suits, Fundamental Changes, and Federal Securities (10b-5, 16(b))

10 Community Property

General Principles, the Community Estate, and Marital Economic Community Characterization: Separate vs. Community Property and Presumptions Tracing and Commingling (Exhaustion and Direct Tracing) Transmutation and Premarital/Marital Agreements Special Assets: Businesses (Pereira/Van Camp), Goodwill, Education, Pensions, Disability Management, Control, and Spousal Fiduciary Duties Debts and Creditors' Rights Distribution at Dissolution and Death; Quasi-Community Property

11 Professional Responsibility

Regulation of the Profession, Admission, and Discipline (California Rules vs. ABA Model Rules) Competence, Diligence, Communication, and Scope of Representation Confidentiality and Its Exceptions (California vs. ABA) Conflicts of Interest: Current Clients Conflicts: Former Clients, Imputation, and Business Transactions Fees, Client Trust Accounts (IOLTA), and Safekeeping Property Duties to the Court and Third Parties: Candor, Advocacy, and Fairness Forming, Declining, and Terminating the Attorney-Client Relationship Advertising, Solicitation, and the Unauthorized Practice of Law Judicial Ethics, Reporting Misconduct, and Special Prosecutor Duties

12 Remedies

Compensatory Damages: Causation, Foreseeability, Certainty, and Mitigation Punitive, Nominal, and Liquidated Damages Restitution and Unjust Enrichment Constructive Trust and Equitable Lien Injunctions: Temporary Restraining Orders, Preliminary, and Permanent Specific Performance Reformation, Rescission, and Cancellation Equitable Defenses, Declaratory Relief, and Remedy Selection

13 Trusts

Trust Creation, Required Elements, and Types of Trusts Charitable Trusts, Cy Pres, and the Rule Against Perpetuities in Trusts Trustee Powers and Trust Administration Trustee Duties: Loyalty, Prudent Investor, and Impartiality Beneficiary Rights and Principal/Income Allocation Spendthrift, Discretionary, and Support Trusts; Creditors' Rights Modification and Termination of Trusts Breach of Trust, Remedies, and Will Substitutes (Totten, POD, Revocable Trusts)

14 Wills and Succession

Intestate Succession and California Distribution Will Execution and Formalities (Attested and Holographic; California) Testamentary Capacity, Undue Influence, Fraud, Duress, and Mistake Will Components: Integration, Incorporation, Acts of Independent Significance, and Pour-Over Revocation, Revival, and Dependent Relative Revocation Lapse, Anti-Lapse, Class Gifts, Ademption, Abatement, and Exoneration Protection of the Family: Omitted Spouse and Child, Pretermitted Heirs Will Contests, Standing, and No-Contest Clauses Probate Administration, Powers of Appointment, and Will Substitutes

15 Performance Test

The Performance Test: Task Memo, File, and Library Objective PT Products: Memos, Briefs, and Client Letters Persuasive PT Products and 90-Minute Execution

The Erie Doctrine and Choice of Law

Key Takeaways Explain This Topic AI

Under Erie Railroad v. Tompkins, a federal court sitting in diversity applies federal procedural law but the substantive law of the state in which it sits; there is no general federal common law.

A federal court in diversity applies the choice-of-law rules of the forum state (Klaxon v. Stentor), then the substantive law selected by those rules.

When a valid Federal Rule of Civil Procedure is directly on point, it controls so long as it is arguably procedural and within the Rules Enabling Act (Hanna v. Plumer).

Where no federal rule is on point, courts use the outcome-determinative test tempered by the twin aims of Erie: discouraging forum shopping and avoiding inequitable administration of the laws.

Statutes of limitations, burdens of proof, elements of state claims, and tolling rules are substantive for Erie purposes and follow state law; pleading standards and the manner of serving process are procedural and follow federal law.

Last updated: June 2026

The Birth of the Erie Doctrine

Before 1938, Swift v. Tyson let federal courts in diversity apply their own 'general federal common law' on matters not governed by state statute. This produced forum shopping and unequal outcomes between state and federal courthouses across the street from each other.

Erie Railroad Co. v. Tompkins (1938) overruled Swift and held: 'There is no general federal common law .' A federal court sitting in diversity must apply:

Federal law to procedural questions (how the litigation is conducted), and

The substantive law of the state in which it sits (the rights and duties being adjudicated).

The constitutional underpinning is that federal courts have no power to create substantive law in areas reserved to the states (the Tenth Amendment / Rules of Decision Act ). The hard cases are those where the federal/state line between 'substance' and 'procedure' is blurry.

Choice of law in diversity

When the case has multistate elements, the federal court does not independently choose which state's law applies. Under Klaxon Co. v. Stentor Electric , it applies the choice-of-law rules of the forum state , then applies the substantive law those rules select. (California uses a governmental-interest analysis , not the older lex loci rule.)

When a Federal Rule Is On Point: Hanna v. Plumer

The analysis branches depending on whether a valid federal directive (a Federal Rule of Civil Procedure or federal statute) is directly on point :

Branch 1 — A Federal Rule is on point (Hanna track)

In Hanna v. Plumer (1965) , the Court held that when a Federal Rule of Civil Procedure directly conflicts with state law, the Federal Rule controls if it is:

Valid under the Rules Enabling Act (28 U.S.C. 2072) — i.e., it is 'arguably procedural' and does not 'abridge, enlarge, or modify any substantive right,' AND

Constitutional (within Congress's power to regulate federal court procedure).

Practically, every duly enacted FRCP has survived this test. In Hanna itself, Rule 4 (manner of serving process — leaving copies at the dwelling) controlled over a Massachusetts rule requiring in-hand service on an executor.

Branch 2 — No Federal Rule on point (Erie/York/Byrd track)

If there is no federal rule directly on point, the court asks whether applying federal practice instead of the state rule would be outcome-determinative .

Guaranty Trust v. York: a state rule is substantive if ignoring it would significantly affect the outcome of the litigation (there, a state statute of limitations barred a diversity equity claim).

The twin aims of Erie (Hanna refinement): apply state law where doing otherwise would (a) encourage forum shopping between state and federal court, or (b) lead to the inequitable administration of the laws .

Byrd v. Blue Ridge: even an outcome-affecting state rule may yield to a strong countervailing federal interest (there, the Seventh Amendment allocation of fact-finding to the jury).

Classifying Issues: Substantive vs. Procedural

Use this checklist on the bar exam. State law (substantive) almost always governs the first group; federal law (procedural) governs the second.

• Follows state law (substantive) Follows federal law (procedural)
• Statute of limitations and tolling rules Whether process was served correctly (Rule 4)
• Elements of the claim or defense Pleading standard (Twombly/Iqbal plausibility)
• Burden of proof and standard of proof Whether to grant a new trial / size of remittitur procedure
• Rules on damages caps and prejudgment interest Discovery scope and devices (Rules 26–37)
• Choice-of-law rules (Klaxon) Allocation of judge/jury roles (Byrd, 7th Amendment)
• Tolling and door-closing statutes The form and timing of motions
• Worked hypothetical

A diversity plaintiff files in federal court in California. State law gives a two-year limitations period and requires a plaintiff to prove fraud by clear and convincing evidence . The federal court will apply both the two-year limit and the clear-and-convincing standard — both are substantive under York and would be outcome-determinative and invite forum shopping if ignored. But the federal court will apply Rule 8(a) plausibility pleading and Rule 4 service rules, even if California's pleading or service rules differ, because those are procedural.

Essay tip: State the branch first — 'Is there a Federal Rule directly on point?' If yes, run Hanna /Rules Enabling Act. If no, run outcome-determinative + twin aims (+ Byrd balancing). Identifying the correct track earns the points.

Common Erie traps and the federal-common-law residue

Trap one: Students apply the outcome-determinative test even when a valid Federal Rule is on point. Don't. When a duly enacted FRCP directly conflicts with state law, Hanna controls and the Federal Rule wins — the York test is never reached . Trap two: Erie applies only to diversity (and supplemental) jurisdiction;

in federal-question cases the court applies federal substantive law, so there is no Erie problem. Trap three: despite Erie 's 'no general federal common law' pronouncement, specialized federal common law still exists in discrete enclaves —

admiralty, interstate disputes, the rights and obligations of the United States , and matters governed by uniquely federal interests. Trap four: a state's 'door-closing' or tolling statute that conditions the very existence of the state-created right is substantive and binds the diversity court, but the manner of commencing the action (Rule 3 vs. a state filing rule) can turn on whether a Federal Rule is on point.

Spotting which track you are on — and naming Erie , York , Byrd , and Hanna in sequence — is what graders reward.