Negligence is commonly described as having four elements: duty, breach, causation, and damages. That framework is accurate as a description of American tort law, but it is not how a California jury is asked the question. California’s pattern jury instruction on negligence, CACI No. 400, is titled “Negligence—Essential Factual Elements,” and it sets out what a plaintiff must prove in three numbered items rather than four: that the defendant was negligent, that the plaintiff was harmed, and that the defendant’s negligence was a substantial factor in causing that harm. Duty and the applicable standard of care are handled separately, and the standard of proof is more likely true than not true.
This article explains the elements of negligence as they are taught, how California’s jury instructions actually frame them, what each element requires in practice, and how the framework changes for premises liability, medical negligence, and claims against public entities. It is written for people trying to understand a real situation rather than for an exam. To talk through a specific case, call our San Mateo office at 650-250-0705. The consultation is free.
Key Takeaways
- The four-element framework (duty, breach, causation, damages) is a useful summary, but California’s pattern instruction states the essential factual elements in three items.
- Duty is generally treated as a legal question for the court, while the standard of care and whether it was met are addressed by separate instructions and decided on the evidence.
- California frames causation as whether the defendant’s negligence was a substantial factor in causing the harm.
- Harm is a required element. Careless conduct that causes no injury or loss does not support a negligence claim.
- The framework shifts by claim type: premises liability, medical negligence, and dangerous conditions of public property each have their own essential elements and their own notice requirements.
The Four Elements as Commonly Described
Most explanations of negligence, including law school treatments and Google’s own AI Overview, use four elements. As a summary of the concept, this is sound:
| Element | What it asks |
| Duty | Did the defendant owe the plaintiff a legal obligation to use reasonable care? |
| Breach | Did the defendant’s conduct fall short of that obligation? |
| Causation | Did that conduct cause the plaintiff’s harm, both in fact and as a matter of law? |
| Damages | Did the plaintiff suffer actual harm? |
Some sources list five elements by splitting causation into factual cause and proximate cause. Others list three. The disagreement is about how to group the same requirements, not about what the law requires.
How California Actually Frames It
California trials run on the Judicial Council of California Civil Jury Instructions, known as CACI. These are the state’s official civil jury instructions, published by the Judicial Council and available free from the California Courts. They are what a judge reads to the jury, so they are the most concrete statement of what a California negligence case has to establish.
The relevant instructions in the negligence series include:
| Instruction | Title | What it addresses |
| CACI No. 400 | Negligence—Essential Factual Elements | What the plaintiff must prove to establish the claim |
| CACI No. 401 | Basic Standard of Care | The level of care the law requires |
| CACI No. 430 | Causation: Substantial Factor | How causation is defined for the jury |
| CACI No. 431 | Causation: Multiple Causes | Cases where more than one cause contributed |
| CACI No. 405 | Comparative Fault of Plaintiff | The defense that the plaintiff’s own negligence contributed |
| CACI No. 418 | Presumption of Negligence per se | Negligence established through violation of a statute or regulation |
| CACI No. 425 | “Gross Negligence” Explained | The heightened form of negligence, where it applies |
| CACI No. 200 | Obligation to Prove—More Likely True Than Not True | The standard of proof in a civil case |
Two things follow from this structure. First, CACI No. 400 asks the jury to decide whether the defendant “was negligent,” which absorbs both duty and breach into a single question about conduct. Second, causation is put to the jury as whether the negligence was a substantial factor in causing the harm, which is California’s formulation rather than a bare “but for” test.
Why duty is usually not a jury question
Whether a duty of care exists is generally decided by the court as a legal question, which is why it does not appear as a numbered item for the jury in CACI No. 400. In ordinary cases, this is uncontroversial: drivers owe other road users reasonable care, and property owners and occupiers owe reasonable care to people on the property. Duty becomes genuinely contested in less typical situations, such as whether a business owed a duty to protect a customer from a third party’s conduct, or whether a professional owed a duty to someone who was not their client. Those arguments are made to the judge, often before trial.
What Each Element Requires in Practice
The standard of care
The general standard is the care a reasonably careful person would use in the same situation. It is not perfection, and it is not measured by hindsight. The standard shifts in defined circumstances: separate instructions address minors, people with a physical disability, more caution in dangerous situations, and higher duties for common carriers. For professionals, including health care providers, the standard is what a reasonably careful professional in the same field would do, which normally requires expert testimony to establish.
Breach
Breach is a factual question about conduct, and it is usually where the evidence is contested. Depending on the case, it can turn on vehicle data, video, inspection and maintenance records, employee testimony, industry custom, or a violated safety regulation. Where a statute or safety regulation was violated, CACI No. 418 provides for a presumption of negligence, which the defendant can then attempt to rebut.
Causation
California puts causation to the jury as substantial-factor causation. In everyday terms, the question is whether the defendant’s negligence contributed meaningfully to the harm, not whether it was the only cause. Where multiple causes contributed, a separate instruction addresses that. Causation is also where a defendant’s strongest argument often lies, particularly when an injury has other possible explanations, such as a pre-existing condition or an intervening event.
Harm
Harm is an element, not an afterthought. Careless conduct that injures no one does not support a claim. Once harm is established, a separate set of instructions governs what may be recovered, dividing damages into economic categories such as past and future medical expenses, lost earnings, and lost earning capacity, and non-economic categories such as physical pain, mental suffering, and loss of enjoyment of life. There is no preset value for any of these, and no attorney can responsibly quote one.
How the Elements Change by Claim Type
“Negligence” is the general framework. Many claims run on a more specific set of essential elements, each with its own instruction series:
- Premises liability. CACI No. 1000 sets out the essential factual elements for premises liability, and CACI No. 1011 addresses constructive notice of dangerous conditions on property. Notice is usually the contested element in a fall case. Our California slip and fall lawyer page explains how actual and constructive notice are proven.
- Medical negligence. CACI No. 500 sets out the essential factual elements, and CACI No. 501 addresses the standard of care for health care professionals. These claims also follow their own limitations rules.
- Dangerous conditions of public property. A separate series applies, built around Government Code section 835, with its own notice instruction tied to Government Code section 835.2. Claims against public entities also require a written claim before any lawsuit.
- Products liability. A product claim may be brought in negligence, in strict liability, or both, and the strict liability theory does not require proof that the manufacturer was negligent.
- Motor vehicles. A dedicated series covers the basic standard of care for drivers along with specific Vehicle Code duties.
This is why the four-element summary only takes an analysis so far. The useful question in a real case is not “are the four elements present” but “which set of essential elements applies, and which one will actually be fought over.”
What Reduces or Defeats a Negligence Claim
- Comparative fault. California follows a pure comparative fault approach. A share of responsibility attributed to the injured person generally reduces the recovery by that percentage rather than barring the claim, and a separate instruction covers apportionment among multiple parties.
- Assumption of risk. In sports and recreational activities, a separate line of instructions addresses when a participant, instructor, or facility operator may not be liable for inherent risks.
- Causation gaps. A defendant may concede carelessness and still contest whether it caused this particular harm.
- Deadlines. A claim that is not brought in time can fail regardless of the merits. Limitations defenses have their own instructions, including delayed discovery.
Deadlines for Negligence Claims in California
| Situation | General rule | Source |
| Most personal injury claims against a private party | Two years | Code Civ. Proc., § 335.1 |
| Claims where a public entity, such as a city, county, transit agency, or state agency, may be responsible | A written claim generally must be presented to the entity within six months, before any lawsuit | California’s Government Claims Act |
| Claims based on a health care provider’s professional negligence | Three years after the date of injury or one year after the injury is discovered (or reasonably should have been), whichever occurs first, subject to statutory exceptions | Code Civ. Proc., § 340.5 |
Negligence Claims in San Mateo County
Our office at 15 North Ellsworth Avenue, Suite 105, San Mateo, CA 94401 works with injured people across the Peninsula. Civil cases in San Mateo County are handled by the Superior Court’s Civil Division at the Hall of Justice in Redwood City, and the court describes alternative dispute resolution, such as mediation, as a way of resolving legal problems without going to trial. Where a city, the County, SamTrans, Caltrain, or a state agency such as Caltrans may share responsibility, the public entity claim process applies and its six-month window can close early in a case.
More about the office is on our San Mateo page, and related explanations are collected in our California personal injury guides.
How Vaksman Khalfin Can Help
Applying this framework to a real situation means identifying which set of essential elements governs, working out which element the other side will contest, and building the evidence for that element before it disappears. Vaksman Khalfin, PC can investigate and preserve that evidence, identify every party and policy that may be involved, present any required public entity claim within its window, and pursue the claim through negotiation and, where a fair resolution is not offered, through litigation.
The firm’s California personal injury practice is led by Alan D. Khalfin, admitted in California. Matters are handled on a contingency-fee basis: there is no upfront attorney’s fee, and attorney’s fees are owed only if there is a recovery. Case costs are a separate category from attorney’s fees, and how they are handled is set out in the written fee agreement, which is reviewed with you before anything is signed. To talk with a lawyer, call 650-250-0705 or schedule a free consultation.
Reviewed by Alan D. Khalfin, Partner and Managing Attorney, Vaksman Khalfin, PC (admitted in California). Last reviewed: 09/17/2026
Frequently Asked Questions
Duty, breach, causation, and damages. A defendant must have owed a legal obligation to use reasonable care, fallen short of it, caused the plaintiff's harm, and that harm must be actual. This is the standard summary used across American tort law.
California's pattern jury instruction on negligence, CACI No. 400, is titled "Negligence—Essential Factual Elements" and states them in three numbered items: that the defendant was negligent, that the plaintiff was harmed, and that the defendant's negligence was a substantial factor in causing that harm. Duty is generally a legal question for the court, and the standard of care is addressed by a separate instruction.
They are grouping the same requirements differently. Four-element lists separate duty from breach. Five-element lists also split causation into factual cause and proximate cause. California's jury instruction folds duty and breach into the single question of whether the defendant was negligent. The underlying requirements do not change.
It is how California puts causation to a jury: whether the defendant's negligence was a substantial factor in causing the plaintiff's harm. The defendant's conduct does not have to be the only cause, and a separate instruction addresses cases involving multiple causes.
Whether a duty exists is generally decided by the court as a matter of law, not by the jury. In ordinary cases it is not disputed. It becomes contested in less typical situations, such as whether a business owed a duty to protect someone from a third party's conduct.
A civil case is decided on whether something is more likely true than not true. That is a lower standard than the proof beyond a reasonable doubt required in a criminal case.
Where a defendant violated a statute or safety regulation, California provides for a presumption of negligence rather than requiring the plaintiff to establish carelessness from scratch. The defendant may attempt to rebut the presumption, including by showing the violation was excused.
Generally no. California follows a pure comparative fault approach, so a share of responsibility attributed to the injured person reduces the recovery by that percentage rather than barring the claim.
Yes. Premises liability and medical negligence each have their own essential factual elements, their own standard-of-care instructions, and, for premises cases, a specific instruction on constructive notice of a dangerous condition. Claims involving dangerous conditions of public property follow a separate framework built around the Government Code.
