Common Law and Case Precedent in California Courts

California courts apply two interlocking bodies of law: enacted statutes and the common law developed through judicial decisions over centuries. This page covers the definition, structural mechanics, typical applications, and decision boundaries of common law and case precedent as they operate within California's state court system. Understanding how courts identify, apply, and distinguish precedent is foundational to comprehending how California's legal system works as a whole.

Definition and scope

Common law is judge-made law — legal rules and principles that emerge from court decisions rather than from legislation. In California, this body of law descends from English common law as adopted at statehood in 1850 and has been continuously refined through appellate decisions ever since. California Civil Code § 22.2 (California Legislative Information) codifies this directly: the common law of England, to the extent it is consistent with the California Constitution and California statutes, is the rule of decision in California courts.

Precedent — the doctrine known formally as stare decisis — obligates courts to follow prior decisions when the same legal question arises under materially identical facts. This is not a constitutional mandate in California but a foundational principle articulated in California Rules of Court, rule 8.1115, which governs the citation of opinions and their binding effect (California Courts, Rules of Court).

Scope of coverage: This page addresses California state common law and precedent as applied in California Superior Courts, the Courts of Appeal, and the California Supreme Court. It does not address federal common law, which operates under distinct principles established by the U.S. Supreme Court. Matters governed exclusively by federal statute, federal constitutional interpretation, or interstate compacts fall outside the scope of California state common law and are not covered here. For the intersection of federal and state authority, see the regulatory context for California's legal system.

Common law doctrines govern large swaths of California civil practice — tort liability, contract formation and breach, property rights, and agency relationships — except where the Legislature has displaced them by statute. When a statute is silent or ambiguous, courts fill gaps with common law principles.

How it works

The operation of common law and precedent in California courts follows a structured hierarchy:

1. Decision by a court of record. A trial court (Superior Court) resolves a legal dispute. Its ruling creates a record but does not constitute binding precedent for other courts.
2. Publication of appellate opinions. The California Courts of Appeal issue opinions, and the California Supreme Court reviews significant questions. Under California Rules of Court, rule 8.1115(a), unpublished Court of Appeal opinions may not be cited or relied on in other actions — only published opinions carry precedential weight.
3. Vertical binding effect. A published Court of Appeal decision binds all Superior Courts in California on the legal propositions it decides. A California Supreme Court decision binds every court in the state.
4. Horizontal persuasive authority. A Court of Appeal in one district is not bound by a published decision from a different district but may consider it as persuasive authority. The California Supreme Court is not bound by its own prior decisions but will overrule them only for compelling reasons.
5. Distinguishing precedent. A court may decline to apply an otherwise binding case if it identifies a material factual or legal distinction that makes the prior decision inapplicable to the case at hand. This "distinguishing" process is separate from overruling.
6. Statutory displacement. If the Legislature enacts a statute that directly addresses the common law rule, the statute controls. Common law fills the spaces left open by legislation, consistent with Civil Code § 22.2.

The California Supreme Court's role as the final arbiter of state law is described further on the California Supreme Court role page. Terminology used in this process — including terms like stare decisis, ratio decidendi, and obiter dicta — is catalogued in the California legal system terminology and definitions reference.

Common scenarios

Common law and precedent apply across the full range of California civil and criminal proceedings. The following represent the most structurally distinct categories:

Tort law. California's negligence framework — including the duty-breach-causation-damages structure — derives primarily from common law, most prominently shaped by the California Supreme Court's decision in Rowland v. Christian (1968) 69 Cal.2d 108, which established the factors for determining whether a duty of care exists. Statutory overlays (e.g., Civil Code § 1714) codify general negligence obligations but courts still rely on case law to interpret their scope.

Contract law. Common law governs formation, interpretation, and breach of contracts not covered by the California Uniform Commercial Code (Commercial Code §§ 2101 et seq.). Courts apply centuries of precedent on offer, acceptance, consideration, and implied covenants, including the implied covenant of good faith and fair dealing recognized throughout California contract jurisprudence.

Property law. Easements, adverse possession, and nuisance doctrine in California are grounded in common law rules adapted by appellate decisions. The California civil procedure basics page addresses how these claims are procedurally initiated.

Criminal law gap-filling. Although California Penal Code § 6 abolishes common law crimes — no act is criminal unless made so by statute — courts routinely use common law principles to interpret statutory terms and define elements of offenses.

Contrast — common law vs. statutory rights: A common law right can be modified or eliminated by the Legislature with ordinary majority vote. A statutory right embedded in the California Constitution requires a constitutional amendment to change. This distinction affects litigation strategy and the durability of any particular legal protection.

Decision boundaries

Not all judicial decisions have equal precedential weight, and California courts apply clear rules to determine which decisions control a given case.

Binding vs. persuasive authority:
- California Supreme Court decisions: binding on all California courts without exception.
- Published Court of Appeal decisions: binding on Superior Courts statewide; persuasive (not binding) between Courts of Appeal of different districts.
- Unpublished Court of Appeal opinions: may not be cited under rule 8.1115(a); carry no precedential weight.
- Federal court decisions interpreting California law: persuasive only; the California Supreme Court has final authority on California law questions.
- Out-of-state decisions: purely persuasive; courts may cite them to illuminate reasoning but are not obligated to follow them.

Retroactivity. When a court overrules a prior decision, the new rule generally applies retroactively to all cases not yet final unless the court expressly limits its ruling to prospective application. The California Supreme Court has articulated limits on retroactivity in criminal cases to protect reliance interests established under prior decisions.

Federal preemption boundary. Where federal law preempts state law — expressly or by field occupation — California common law and statutes yield entirely. This boundary is litigated frequently in areas such as labor relations governed by the National Labor Relations Act and airline regulation under the Airline Deregulation Act. These federal preemption questions are outside the scope of California common law doctrine and are addressed in the context of federal courts in California.

Scope limitations: Common law and precedent as described here apply only within California state jurisdiction. Tribal courts operating under California's 109 federally recognized tribes follow their own sovereign law and are not bound by California common law except as specifically adopted by tribal ordinance — a separate framework addressed on the California indigenous tribal law intersections page.

For a broader orientation to how statutes, administrative regulations, and constitutional provisions interact with common law, the California legal system overview provides a structural map of these intersecting authorities. The California appellate court process page details the procedural mechanics by which precedent is created, certified for publication, and applied in subsequent proceedings.

References

• California Civil Code § 22.2 — Adoption of Common Law
• California Rules of Court, Rule 8.1115 — Citation of Opinions
• California Legislative Information — Civil Code
• California Courts — Rules of Court (Official Text)
• California Supreme Court — Published Opinions
• California Penal Code § 6 — Abolition of Common Law Crimes
• California Commercial Code §§ 2101 et seq. — Uniform Commercial Code