
In California, the reasonable person standard works by comparing an allegedly negligent party’s conduct to what a hypothetical reasonable person would have done in the same or similar circumstances.
If a defendant fails to act like an objectively reasonable person would have, it can amount to a breach of their duty of care towards you as the victim and plaintiff.
As a “standard,” the reasonable person standard is not as precise or absolute as a statute or other laws. Though judges and juries rely heavily on standards such as “the reasonable person” when deciding whether the law has been broken.
In this article I answer frequently-asked-questions about the reasonable person standard in California. Also listen to our informative podcast on the subject:
What is a “reasonable person”?
A “reasonable person” is a fictitious person in California law who always uses ordinary care under the circumstances.1 They are sometimes said to use “prudence” or “reasonable care.”
The reasonable person does not exist in real life. However, people who do not act like the reasonable person can be held liable for injuries that their poor conduct causes.
When they do not act like a reasonable person, they behave unreasonably for the circumstances. This is evidence of negligence.2
Is it a subjective or an objective standard?
The reasonable person is an objective test or standard in California law.
A defendant cannot escape liability by arguing that they were personally unaware of the dangers of their conduct. If a reasonably prudent person would have been aware of them in a similar situation, then the defendant can be held liable.
Example: A farmer stacks hay right near his neighbor’s house. He is told repeatedly not to do so, as the weather is dry and the hay can catch fire. A week later, the hay accidentally ignites and burns down the neighbor’s house.
However, the reasonable person matches the skills or expectations of the defendant for the particular situation. At common law, defendants are compared to a reasonable person who is similar to them.3
Dog Owners
If you are injured by a dog, like in a dog bite case, the defendant is negligent if they did not act like a reasonable dog owner. California law requires appropriate care for the dog and taking reasonable and effective steps to control the animal and prevent an attack.4

Dog owners are expected to take reasonable steps to prevent dog bites and attacks.
Blind People
It would be unfair to expect blind people to behave like a typical person who could see. Therefore, in California, people who cannot see are held to the standard of conduct of a reasonably prudent blind person.
Some conduct that would be negligent for a seeing person to do would not be negligent for a blind person. However, some conduct that would not be negligent for a seeing person can violate the reasonably prudent blind person standard; for instance, a blind person should not get into a car and drive.
Children
In California, the reasonable person standard only applies to adults. To determine negligence, children are held to the much more subjective standard of care of a minor of the same age, intelligence, and experience.5
However, minors can be judged by the standard of a reasonable adult if the minor was engaged in an adult activity, such as driving a car.6
Note that adults who have swimming pools or other “attractive nuisances” on their property have a duty to make them inaccessible to trespassing children, who cannot be expected to keep themselves safe. This is why many counties require pool owners to have a gate.7
Emergencies
A person acts differently in an emergency than in other moments. The stressful situation and the need for immediate action drastically increase the likelihood that the defendant’s conduct proves to be negligent in the long run.
To account for this in California law, a person’s conduct in an emergency is held against the standard of a reasonable person acting in the context of an unforeseen emergency.8

Doctors are held to the standard of other doctors in their field.
Doctors and Others with Special Skills
In California, people with special skills are typically held to the standard of a reasonable person with their special skills.
For example, medical providers like doctors and surgeons have to meet the standard of care of others in their profession or medical field. If they fail to do so, it can amount to medical malpractice.9
A good Samaritan trying to bind a car crash victim’s wound would be held to a lower standard than a doctor because they lack a doctor’s training.
How does the reasonable person standard fit into personal injury law?
If you have been hurt by someone else’s negligence, you have to show four things to recover compensation under California tort law:
- the defendant owed you a legal duty of care,
- the defendant breached that duty of care,
- that breach caused your injuries, and
- your injuries resulted in damages.10
An example of a “duty of care” is a store owner fixing any dangerous conditions on the premises (or warning patrons of them) so that no one gets hurt. Though if a burglar were to break in after hours and slip on a spill the janitor failed to clean, the store owner would probably not be negligent because they could not have reasonably foreseen a burglar breaking in.
Note that negligence per se is a similar cause of action to negligence in California: It occurs when:
- There is a law or statute that exists to protect a class of persons;
- You are a member of that class;
- The defendant violated the law or statute; and
- The defendant’s violation of the law caused your injuries.
The most common example of negligence per se is the defendant speeding, which then causes a crash with another driver. Here, the defendant was negligent per se because they broke a traffic law meant to protect other drivers and did in fact injure another driver.
Proving Negligence or Negligence Per Se
As with any California civil case, you as the plaintiff have the burden to prove to the judge or jury that the defendant is liable for injuring you. To do this, your personal injury attorney would compile such evidence as:
- medical records of your injuries before and after the accident,
- GPS records (if applicable),
- eyewitness accounts of the accident,
- video surveillance of the accident,
- accident reconstruction expert testimony, and/or
- a lifecare plan, which outlines all the expenses you have due to your injury (such as home health care, home renovations to accommodate a wheelchair, childcare expenses, etc.).
Your attorney would then negotiate aggressively with the defendant to maximize your settlement so you get all the money you are entitled to as quickly as possible and without the time and expense of a trial.
What Insurance Pays For
Most personal injury payouts come from the at-fault party’s:
- homeowner’s insurance, if you are injured on another person’s property
- commercial insurance, if you are injured on a commercial property
- automobile insurance, if you are injured in a car crash
In case you are injured by someone who has no insurance or has a small policy, you are advised to carry:
If necessary, your personal injury attorney can bring a lawsuit against the at-fault party in pursuit of all your damages not covered by their insurance. Just make sure that you contact an attorney as soon as possible after an accident.
Just do not delay in seeking legal counsel. In most California personal injury cases, you have only a two-year statute of limitations to file a lawsuit. The time limit to sue can be even a few months in some cases.11

The majority of personal injury lawsuits resolve with a settlement and no trial.
Additional Reading
For more in-depth information, refer to these scholarly articles:
- The Reasonable Person Standard: Psychological and Legal Perspectives – Annual Review of Law and Social Justice.
- The Empirical Reasonable Person – Alabama Law Review article on how the reasonable standard is used in law.
- Cultural Norms as Law: Tort Law’s “Reasonable Person” Standard of Care – Journal of American Culture.
- On Determining Negligence: Hand Formula Balancing, the Reasonable Person Standard, and the Jury – Vanderbilt Law Review.
- The Counterpoise of Contracts: The Reasonable Person Standard and the Subjectivity of Judgment – South Carolina Law Review.
Legal References:
- See Fox v. City and County of San Francisco (1975) 47 Cal.App.3d 164.
- See California Civil Jury Instructions (CACI) No. 401. The reasonable person is not just any ordinary person. They are an adult that always uses common sense, avoids putting other people into risk of harm, and is always paying attention. They never forget things and are always aware of reasonably foreseeable harms or dangers in a given situation. Restatement (Second) Torts, section 284. Negligence can take the form of an action, or a failure to act. See also Carrillo v. County of Santa Clara (Cal.App. 2023) 9 Cal. App. 5th 227; Carr v. City of Newport (Cal.App. 2023) 94 Cal. App. 5th 1199.
- Facts from Vaughan v. Menlove (1937) 132 ER 490, an English common law case. See also McQuire v. Western Morning News (1903) 2 KB 100 (clarifying that the reasonable passenger on the horse-drawn carrier “Clapham omnibus” is based on an objective standard).
- See Drake v. Dean (1993) 15 Cal.App.4th 915.
- See CACI No. 402.
- Prichard v. Veterans Cab Co. (1965) 63 Cal.2d 727.
- See City of Lakewood v. Congdon (Superior Court of Los Angeles in California, 2022) 22NWCP00034.
- Mann v. State of California (1977) 70 Cal. App. 3d 773.
- Restatement (Second) Torts, section 299A. The standard of care does not require average skill or performance. If that were the case, then half of the medical professionals would fall below the required standard of care. The degree of specialty can further heighten the standard of care. Many states, like California, differentiate between healthcare professionals and medical specialists. CACI No. 501. CACI No. 502.
- The standard of a reasonable person is a way of showing that there was a breach of a legal duty of care. If the defendant had a legal duty of care to keep you out of harm’s way, they have to provide this degree of care. They can do this by behaving as a reasonable person would behave in the same circumstances. If they do not abide by this legal standard, they can be held liable in a personal injury case.
- CCP § 335.1.