US Tort Law

Sources and Structure of US Tort Law

US tort law is primarily state common law, developed through judicial decisions rather than codified statutes. The American Law Institute’s Restatements of Torts — the Restatement (Second) (1965–1979) and the Restatement (Third) (2000–present) — serve as influential guides, though they lack binding authority. Individual states retain interpretive autonomy, producing significant variation in doctrinal rules across jurisdictions.

Intentional Torts

Intentional torts require the actor to desire or know with substantial certainty that the harmful consequences will occur. Battery is the intentional infliction of a harmful or offensive bodily contact. Consent, actual or apparent, operates as a complete defence. Assault involves the intentional creation of a reasonable apprehension of imminent harmful or offensive contact, without requiring physical touching. False imprisonment requires an act confining another within boundaries fixed by the actor, with no reasonable means of escape, and the victim’s awareness of confinement or actual harm.

Intentional Infliction of Emotional Distress (IIED), recognised in the Restatement (Second) § 46, requires extreme and outrageous conduct intentionally or recklessly causing severe emotional distress. Trespass to land is intentional intrusion upon another’s land; trespass to chattels is intentional interference with personal property, while conversion is a more serious interference justifying forced sale.

Negligence

Negligence, the dominant tort, comprises four elements: duty, breach, causation, and damages.

Duty is the legal obligation to conform to a standard of reasonable care. Palsgraf v. Long Island Railroad Co. (1928) established that duty is owed only to those within the foreseeable zone of danger. The Restatement (Third) of Torts § 7 provides that an actor has a duty to exercise reasonable care when the risk of physical harm is foreseeable. Special duties arise for landowners, medical professionals, and common carriers.

Breach is conduct falling below the applicable standard of care. Judge Learned Hand’s formula in United States v. Carroll Towing Co. (1947) articulates breach as a function of three variables: the probability of harm (P), the gravity of the resulting injury (L), and the burden of adequate precautions (B). Liability attaches if B < P × L. The Restatement (Third) § 3 adopts this economic conception: an act is negligent if the foreseeable risk outweighs what the reasonable person would regard as justified.

Causation divides into factual and proximate causation. Factual cause is determined by the “but-for” test: the injury would not have occurred absent the defendant’s conduct. Where multiple sufficient causes exist, the substantial factor test applies. Proximate cause limits liability to harms that are foreseeable consequences of the negligent conduct, cutting off liability for remote or highly unusual results (Palsgraf).

Res ipsa loquitur permits a presumption of negligence when the injury would not ordinarily occur absent negligence, the instrumentality was within the defendant’s exclusive control, and the plaintiff did not contribute to the injury. The seminal case is Byrne v. Boadle (1863), adopted in Ybarra v. Spangard (1944).

Strict Liability

Products liability imposes strict liability on commercial sellers of defective products. The Restatement (Third) of Torts: Products Liability § 1 provides that a seller is liable for harm caused by a manufacturing defect, design defect, or failure to warn. A manufacturing defect occurs when the product departs from its intended design; a design defect exists when foreseeable risks could be reduced by a reasonable alternative design; a warning defect exists when inadequate instructions or warnings render the product unsafe. The Restatement (Second) § 402A, which required the product to be in a “defective condition unreasonably dangerous,” remains the law in many states. Greenman v. Yuba Power Products (1963) and Henningsen v. Bloomfield Motors (1960) are foundational.

Abnormally dangerous activities carry strict liability under Restatement (Second) § 520 and the rule in Rylands v. Fletcher (1868), adopted in US law. Factors include high degree of risk, likelihood of serious harm, inability to eliminate risk through reasonable care, and the activity not being a matter of common usage. Blasting, storage of hazardous chemicals, and nuclear operations are typical applications.

Defences

Contributory negligence, the traditional common law rule, bars recovery entirely if the plaintiff’s negligence contributed to the injury. Most states have replaced it with comparative fault, which apportions damages based on the plaintiff’s percentage of fault. Two forms exist: pure comparative fault (plaintiff recovers reduced damages regardless of fault percentage, adopted in California’s Li v. Yellow Cab Co. 1975) and modified comparative fault (plaintiff recovers only if fault is less than or not greater than 50%, adopted in most states). Assumption of risk bars recovery when the plaintiff voluntarily and knowingly encounters a known danger; express assumption is contractual, while implied assumption may be primary or secondary.

Damages

Compensatory damages restore the plaintiff to the pre-injury position, covering medical expenses, lost earnings, pain and suffering, and loss of consortium. Punitive damages, intended to punish egregious misconduct and deter future wrongdoing, are subject to constitutional constraints. BMW of North America, Inc. v. Gore (1996) established three guideposts: the reprehensibility of the defendant’s conduct, the ratio between punitive and compensatory damages, and the comparison to civil penalties available for comparable misconduct. Single-digit ratios are generally required; ratios exceeding 9:1 violate due process.

Nuisance

Private nuisance involves substantial and unreasonable interference with the use and enjoyment of land. Public nuisance involves interference with a right common to the public. Courts balance the gravity of the harm against the utility of the defendant’s conduct. Nuisance may sound in trespass where there is physical invasion.

Defamation

Defamation requires a false statement of fact, published to a third party, causing injury to reputation. US defamation law is substantially shaped by the First Amendment. New York Times Co. v. Sullivan (1964) held that public officials cannot recover absent proof of “actual malice” — knowledge of falsity or reckless disregard for truth. Gertz v. Robert Welch, Inc. (1974) extended the actual malice standard to public figures but permitted states to establish lower standards for private individuals, provided strict liability is not imposed and presumed damages are unavailable absent fault. Truth is a complete defence.

Privacy Torts

Prosser’s four privacy torts, recognised in the Restatement (Second) §§ 652A–652I, are: intrusion upon seclusion, public disclosure of private facts, false light publicity, and appropriation of name or likeness. These torts protect the individual’s interest in solitude, confidentiality, reputation, and control over personal identity. Constitutional limits apply to matters of public concern.

Economic Torts

Intentional interference with contract requires the existence of a valid contract, the defendant’s knowledge, intentional and unjustified inducement of breach, and resulting damage. Intentional interference with prospective economic advantage protects business expectancies. Fraud and negligent misrepresentation constitute torts arising from commercial dealings. The economic loss rule generally bars tort recovery for purely economic losses arising from a contract, preserving the boundary between tort and contract law.

Tort and Contract Distinction

Tort duties arise from law and social policy, owed to the world at large; contractual duties arise from the parties’ agreement, owed only to the promisee. Tort remedies seek to restore the plaintiff to the pre-injury position; contract remedies aim to place the injured party in the position they would have occupied had the contract been performed. The economic loss rule protects this boundary: a plaintiff cannot recover in tort for a purely economic loss caused by a defective product that damages only itself, absent personal injury or property damage.