Negligence Law: Duty, Breach, Causation, and Damages Explained

The Legal Framework for Everyday Harm

Car accidents injure more than 2 million Americans each year. Slip-and-fall incidents account for over 1 million emergency room visits. Medical errors harm hundreds of thousands of patients. Behind the statistics is a legal question courts have answered millions of times: when one person's carelessness hurts another, who pays? Negligence law is the body of doctrine that answers this question. It is the foundation of most personal injury litigation and one of the most practically important areas of civil law.

The Four Elements Every Plaintiff Must Prove

To prevail on a negligence claim, a plaintiff must establish four distinct elements by a preponderance of the evidence — meaning it is more likely than not that each element is satisfied. All four are required. A weakness in any one defeats the claim.

Duty of Care

Duty is a legal obligation to conform to a certain standard of conduct for the protection of others. Not everyone owes a duty to everyone else — duty depends on the relationship between the parties and the foreseeability of harm. Courts examine whether the defendant was in a position where their conduct could reasonably be expected to affect the plaintiff.

The general duty rule in most jurisdictions holds that everyone has a duty to act as a reasonably prudent person to avoid creating unreasonable risks of harm to foreseeable plaintiffs. Special relationships create heightened duties. A doctor owes a higher standard of care to a patient than a stranger would. An employer owes a duty to maintain a safe workplace for employees. A property owner owes different duties to invitees, licensees, and trespassers — with trespassers generally receiving the least protection.

• No duty to rescue: Under traditional American common law, there is generally no legal duty to rescue a stranger in peril, even if rescue would be easy and safe. A bystander who watches someone drown without intervening is not liable in most states.
• Assumed duty: Once a person voluntarily undertakes a rescue or renders aid, they may assume a duty to continue with reasonable care.
• Special relationship duties: Innkeepers, common carriers, schools, and employers all owe enhanced duties to persons in their care based on the special relationship.

Breach of Duty

Breach occurs when a defendant's conduct falls below the applicable standard of care. The standard is that of a reasonable person — an objective, hypothetical individual of ordinary prudence exercising ordinary care under the same or similar circumstances. The reasonable person is not a paragon of perfection, but neither is they reckless or indifferent to others' safety.

Courts and juries consider several factors when determining whether conduct was reasonable, often framed by the Hand Formula articulated by Judge Learned Hand in United States v. Carroll Towing Co. (1947). The formula holds that conduct is negligent when the burden of precaution (B) is less than the probability of harm (P) multiplied by the gravity of potential injury (L): negligence occurs when B < P × L. A small cost to prevent a high-probability, high-severity harm is almost certainly negligent to forgo.

Causation: Two Distinct Requirements

Even when duty and breach are established, the plaintiff must show the breach actually caused their injury. Causation has two components, both of which must be satisfied.

Actual cause (cause-in-fact) is typically determined by the but-for test: but for the defendant's breach, the plaintiff's injury would not have occurred. If the injury would have happened even without the defendant's negligence, causation fails. When multiple defendants each independently could have caused the harm, courts may apply the substantial factor test: was the defendant's conduct a substantial factor in bringing about the result?

Proximate cause (legal cause) limits liability to consequences that were a foreseeable result of the negligence. Even if the defendant's breach was the but-for cause of harm, liability does not extend to consequences that are too remote, too attenuated, or entirely unforeseeable. The classic case is Palsgraf v. Long Island Railroad (1928), in which Judge Benjamin Cardozo held that a railroad employee's negligent act — helping a passenger board a moving train, causing fireworks to fall and explode — did not create liability to a woman injured far down the platform by scales knocked over by the explosion. The harm was not foreseeable to the plaintiff's position.

Comparative and Contributory Fault

Few negligence cases involve a plaintiff who was entirely blameless. Most states have adopted some form of comparative fault that reduces or eliminates recovery based on the plaintiff's own negligence.

Damages

Negligence requires actual, provable harm. Without damages, there is no negligence claim even if duty, breach, and causation are all present. This distinguishes negligence from intentional torts, where nominal damages may be available.

Compensatory damages aim to restore the plaintiff to the position they were in before the injury. They divide into two categories:

• Economic (special) damages: Medical expenses, lost wages, future lost earning capacity, rehabilitation costs, property damage. These are calculable from bills, pay stubs, and expert testimony.
• Non-economic (general) damages: Pain and suffering, emotional distress, loss of enjoyment of life, loss of consortium. These are inherently subjective and vary widely across verdicts for comparable injuries.

Punitive damages — available only when the defendant's conduct was egregious, reckless, or malicious — are rare in negligence cases. Most negligence is careless, not malicious, and punitive damages require a higher threshold of culpability.

Negligence Per Se

When a defendant violates a statute or regulation designed to protect a class of persons from a specific type of harm, many jurisdictions apply the doctrine of negligence per se: the statutory violation establishes breach of duty as a matter of law, removing that element from jury consideration. The plaintiff must still show the violation caused their injury and that they fall within the protected class. Traffic violations are the most common context — running a red light and striking a pedestrian triggers negligence per se analysis in most states.

Negligence in Practice

Negligence litigation is the backbone of the American civil justice system. Automobile accidents, medical malpractice, product liability, premises liability, and professional negligence claims together account for hundreds of billions of dollars in annual verdicts and settlements. Insurance companies have developed sophisticated actuarial models around negligence exposure. Understanding the doctrine's four elements — and the many ways courts have refined them — is essential to understanding how civil liability is allocated in everyday American life. This article is for informational purposes only and does not constitute legal advice.