Every case against a city, county, transit district, or school board starts from the same disadvantage: under Government Code section 815, a public entity is not liable for an injury except as a statute provides. There is no common-law tort claim against a public entity in California. You are building on a statutory foundation, and the defense will meet each element with an immunity drawn from the same code.
The good news for plaintiffs is that the California Supreme Court has spent its last several terms reading two of the broadest immunities narrowly. Section 821.6 no longer swallows every investigation-related injury, and design immunity under section 830.6 no longer forecloses a separate failure-to-warn theory. Neither ruling opens a floodgate, but each restores a claim that defense counsel had grown used to dismissing at the pleading stage.
The Baseline: Statute First, Immunity Second
Public-entity liability runs through three main channels. Section 815.2 imposes vicarious liability for an employee's tortious act committed in the scope of employment, subject to whatever immunity the employee would enjoy. Section 815.6 creates direct liability where an enactment imposes a mandatory duty designed to protect against the kind of injury suffered and the entity fails to discharge it. And sections 830 through 835 govern the dangerous-condition-of-public-property claim, which requires a physical defect, a causal link to the injury, foreseeability of that kind of harm, and either actual or constructive notice or a negligent act by an employee.
Miss the claim-presentation deadline and none of that matters. Under section 911.2, a personal-injury or wrongful-death claim must be presented to the entity within six months of accrual, and section 945.4 bars suit until the claim is presented and rejected. The six-month window is the single most common way these cases die, and relief under section 946.6 for late claims is discretionary and grudging. Calendar the claim date before you calendar anything else.
Leon Narrows Section 821.6
Section 821.6 immunizes a public employee from liability for "instituting or prosecuting any judicial or administrative proceeding." For years the defense bar read that language expansively, citing older appellate authority to immunize almost any conduct connected to an investigation, whether or not a prosecution ever followed.
In Leon v. County of Riverside (2023) 14 Cal.5th 910, the Supreme Court closed that reading. The case arose when sheriff's deputies left a shooting victim's body partially exposed on a public sidewalk for hours in front of his widow. The county argued section 821.6 immunized the deputies because the conduct occurred during a criminal investigation. The Court held that section 821.6 immunizes only claims for malicious prosecution — it does not reach other injuries an employee inflicts during an investigation. The immunity tracks the tort it was written to bar, and no further.
The practical consequence is that investigatory-phase conduct — how officers handle a scene, a body, evidence, or a bystander — is again reachable where it causes an independent injury, so long as you are not pleading malicious prosecution in substance. Expect the defense to reframe your allegations as prosecution-adjacent to pull them back under the immunity; plead the injury as one that exists independent of any charging decision.
Tansavatdi and the Failure-to-Warn Carve-Out
Design immunity under section 830.6 is the defense workhorse in roadway and public-improvement cases. Prove three elements — a causal connection between the design and the injury, discretionary approval of the design before construction, and substantial evidence supporting the reasonableness of that approval — and the entity is immune even from a demonstrably dangerous design.
In Tansavatdi v. City of Rancho Palos Verdes (2023) 14 Cal.5th 639, a cyclist was killed at an intersection that lacked a bike lane the city had elsewhere installed. The city won summary judgment on design immunity. The Supreme Court reversed the reflex that design immunity ends the inquiry. It held that even where design immunity applies, a public entity may still owe a duty to warn of a concealed dangerous condition that the approved design created, and that failure-to-warn theory survives the immunity. The Court remanded for the lower court to evaluate whether the record showed a concealed trap requiring a warning.
That is a distinct claim you must plead affirmatively. The question becomes whether the danger was concealed from a reasonably careful road user and whether an adequate warning would have reduced the risk — issues that turn on sight lines, signage history, and prior-incident data at the location. This is where your traffic-engineering and human-factors experts earn their fee, and where the reliability gatekeeping in the California expert-challenge cases worth knowing becomes the real battleground rather than the immunity itself.
The Immunities That Held
Not every doctrine has softened. Discretionary-act immunity under section 820.2 still bars claims premised on genuine policy judgments — the basic decision to adopt a program or allocate resources — as distinct from the operational execution of that decision. The line between a discretionary policy choice and a ministerial operational failure remains the fight, and it is fact-bound.
Trail immunity under section 831.4 continues to defeat claims arising from the condition of a trail used for recreation, and courts read "trail" broadly to include paved paths and access roads. The workable distinction is between an injury caused by the trail's physical condition, which is immune, and one caused by a separate hazard such as a falling tree limb adjacent to the trail, which may not be. Section 845 still immunizes the failure to provide police protection or sufficient personnel, and section 845.6 preserves a narrow exception for failure to summon immediate medical care for a prisoner with an obvious serious need.
Dangerous-condition claims themselves live or die on notice and foreseeability, and the analysis rhymes with private premises law even though the statute controls. The foreseeability calculus for a third party's criminal or negligent act on public property borrows the same reasoning developed in the private-landowner cases we covered in the premises-foreseeability sliding-scale discussion, and the entity's constructive-notice defense usually rises or falls on maintenance and inspection records you have to pry loose in discovery.
What This Means for Case Selection and Pleading
Screen the claim presentation first — six months, no exceptions worth relying on. Then plead the statutory basis for liability with specificity: identify the enactment for a section 815.6 mandatory-duty claim, or the physical defect and notice for a dangerous-condition claim, rather than pleading negligence in the abstract. Anticipate the immunity that answers your theory and plead the facts that take you outside it: the independent injury for a section 821.6 defense, the concealed-trap warning theory for a section 830.6 defense, the operational rather than policy character of the conduct for a section 820.2 defense.
Records discovery does the heavy lifting. Inspection logs, prior-incident reports, design-approval files, and internal maintenance requests decide notice, reasonableness, and concealment. Public entities resist producing them, and the sanctions exposure for stonewalling is real — the same pressure points documented in the discovery-sanctions trends in California PI practice apply with equal force to a recalcitrant municipal defendant.
The framework has not been rewritten. Section 815 still means you start with no claim and build one from the code. But Leon and Tansavatdi are a reminder that the broadest immunity readings are the most vulnerable ones, and that a claim the defense treats as foreclosed at the pleading stage may only be foreclosed under the version of the statute that no longer controls.