What is stare decisis?
The Latin phrase means “to stand by things decided.” When a higher court decides a legal question, later courts follow that answer. Judges do this even when they might have decided the question differently if it were new.
The California Supreme Court has explained why. Certainty and stability are major goals of the legal system. People need to plan their lives and businesses knowing what the rules are. (Moradi-Shalal v. Fireman’s Fund Ins. Companies (1988) 46 Cal.3d 287, 296.) The doctrine also keeps decisions grounded in law instead of in the views of whoever sits on the bench that year.
For injured people, this matters in concrete ways. The rule that your own share of fault reduces your recovery instead of erasing it comes from a 1975 decision, Li v. Yellow Cab Co. (1975) 13 Cal.3d 804. Rules on public entity liability, sports injuries and insurance claims all rest on precedent. If those rulings could change every time the court’s membership changed, no one could predict the value of a case.
Can courts overrule precedent?
Yes. The California Supreme Court treats stare decisis as a basic policy, not a fixed command. It should not shield court-made error from correction. (Moradi-Shalal, 46 Cal.3d at p. 296.) But disagreement is not enough. There must be a change in the law or facts, or another special justification. (Hernandez v. Restoration Hardware, Inc. (2018) 4 Cal.5th 260.)
California law puts the idea in one sentence: “When the reason of a rule ceases, so should the rule itself.” (Civ. Code, § 3510.) Justice Oliver Wendell Holmes said it more sharply in 1897. It is “revolting,” he wrote, to keep a rule only because it was laid down in the time of Henry IV.
California’s own history shows overruling cuts both ways:
- It helped injured people. Li overruled the old all-or-nothing rule of contributory negligence, under which any fault by the victim barred recovery.
- It hurt injured people. Moradi-Shalal overruled Royal Globe Ins. Co. v. Superior Court (1979) 23 Cal.3d 880. Since 1988, an injured person generally cannot sue the at-fault driver’s insurer under the unfair claims practices statute.
- It fixed court-made error. Freeman & Mills, Inc. v. Belcher Oil Co. (1995) 11 Cal.4th 85 overruled Seaman’s. Riverisland Cold Storage, Inc. v. Fresno-Madera Production Credit Assn. (2013) 55 Cal.4th 1169 overruled a 1935 fraud rule.
Why did the court keep precedent in Tansavatdi?
In March 2016, Jonathan Tansavatdi was riding his bicycle in Rancho Palos Verdes when a truck making a right turn ran over him. He died. His mother sued the city under Government Code section 835 for a dangerous condition of public property. The city relied on design immunity. That rule protects public entities from liability for injuries caused by an approved, reasonable design. (Gov. Code, § 830.6.)
Since 1972, California has held that design immunity does not excuse a public entity from warning about a dangerous condition it knows about. (Cameron v. State of California (1972) 7 Cal.3d 318.) The city asked the court to overrule Cameron. The court refused. (Tansavatdi v. City of Rancho Palos Verdes (2023) 14 Cal.5th 639.) The city had not shown a special justification. Cameron had controlled for more than 50 years. A legislative committee had recommended abrogating it, and the Legislature amended the design immunity statute without doing so.
That last point is important. When a court interprets a statute, stare decisis has extra force because the Legislature can change the result if it disagrees. (People v. Latimer (1993) 5 Cal.4th 1203, 1213.) Constitutional rulings are different. Only the court, or a constitutional amendment, can change them.
New in September 2026: the same family’s case returned to the Court of Appeal. On remand, the trial court found that the city’s warning signs and markings were part of its approved 2009 design. The Court of Appeal affirmed judgment for the city. It held that when some warning is part of an approved and reasonable design, a claim that the warning was inadequate falls within design immunity. (Tansavatdi v. City of Rancho Palos Verdes (Sept. 24, 2026, B343512) [certified for publication].) Winning the precedent fight does not guarantee winning the case. If you were hurt on a road or sidewalk, see our pages on government entity claims and pedestrian accidents.
How does the U.S. Supreme Court decide whether to overrule?
In Dobbs v. Jackson Women’s Health Organization (2022) 597 U.S. 215, the Court overruled Roe v. Wade and Planned Parenthood v. Casey. It listed five factors: how badly the earlier case erred, the quality of its reasoning, whether its rule was workable, its effect on other areas of law, and reliance interests. The dissent said nothing had changed but the Court’s membership.
Those factors now appear in case after case. The Court has also pointed out that some of its most important decisions overruled precedent. Brown v. Board of Education (1954) 347 U.S. 483 rejected Plessy v. Ferguson (1896) 163 U.S. 537.
What’s new since 2025
- Loper Bright Enterprises v. Raimondo (2024) 603 U.S. 369. Decided June 28, 2024, it overruled Chevron (1984), which had told courts to defer to federal agencies’ reasonable readings of unclear statutes. Courts now decide for themselves what those statutes mean. That can change how courts read federal safety regulations, including rules for trucking and vehicles.
- Trump v. Slaughter (June 29, 2026, No. 25-332). By a 6-3 vote, the Court held that the FTC’s for-cause removal protection violates the separation of powers. It overruled what remained of Humphrey’s Executor v. United States (1935) 295 U.S. 602.
- Quach v. California Commerce Club, Inc. (2024) 16 Cal.5th 562. On July 25, 2024, the California Supreme Court abandoned the prejudice requirement for waiving arbitration that it adopted in 2003. A company that litigates in court instead of promptly demanding arbitration can now lose the right to arbitrate without the other side proving harm. The court acted because the federal rule its earlier case relied on had been rejected.
- Hohenshelt v. Superior Court (Aug. 11, 2025, S284498). The court upheld California’s deadline for companies to pay arbitration fees, but held that a late payment can be excused in limited circumstances. It disapproved 11 Court of Appeal decisions to the extent they conflicted.
The lesson: precedent that looks settled can move quickly, especially when the reasoning behind it has been undercut.
What this means for you
If a precedent stands in the way of your claim, that is not always the end. Lawyers evaluating whether to challenge it look at:
- how old it is, and whether its reasons still hold (Trope v. Katz (1995) 11 Cal.4th 274);
- whether it was unanimous (Woollacott v. Meekin (1907) 151 Cal. 701);
- how much people have relied on it, and whether it fits related rules (Latimer, 5 Cal.4th 1203);
- whether later courts have followed it, criticized it or narrowed it;
- whether other states have adopted or rejected it.
Timing matters too. A challenge to precedent usually has to be raised early and preserved at each stage, because only a higher court can overrule it. And when a helpful precedent is under attack, as in Tansavatdi, the injured person needs a lawyer ready to defend it. Our article on insurance bad faith shows how much of that area also rests on precedent.
Frequently asked questions
What does stare decisis mean in simple terms?
It means courts follow earlier decisions on the same legal question. It keeps the law predictable, so people and courts know what rules apply.
Can the California Supreme Court overrule itself?
Yes, but it requires a special justification, such as a change in the law or facts. Saying the old case was wrong is not enough. It did so in 2024 in Quach.
Can a trial court ignore a Court of Appeal decision it disagrees with?
No. California trial courts must follow California Supreme Court decisions and published Court of Appeal decisions. (Auto Equity Sales, Inc. v. Superior Court (1962) 57 Cal.2d 450.) Only a higher court can overrule them.
Why does precedent matter to someone hurt in an accident?
Rules on comparative fault, government liability and insurance claims come largely from court decisions. If those decisions change, what you can recover can change too.