A tort, in common law jurisdiction, is a civil wrong (other than breach of contract) that causes a claimant to suffer loss or harm, resulting in legal liability for the person who commits a tortious act. It can include intentional infliction of emotional distress, negligence, financial losses, injuries, invasion of privacy, and many other things. The word 'tort' stems from Old French via the Norman Conquest and Latin via the Roman Empire.

Tort law involves claims in an action seeking to obtain a private civil remedy, typically money damages. Tort claims may be compared to criminal law, which deals with criminal wrongs that are punishable by the state. A wrongful act, such as an assault and battery, may result in both a civil lawsuit and a criminal prosecution in countries where the civil and criminal legal systems are separate. Tort law may also be contrasted with contract law, which also provides civil remedies after breach of a duty that arises from a contract; but whereas the contractual obligation is one agreed to by the parties, obligations in both tort and criminal law are more fundamental and are imposed regardless of whether the parties have a contract. In both contract and tort, successful claimants must show that they have suffered foreseeable loss or harm as a direct result of the breach of duty.

Terminology.

The person who commits the act is called a tortfeasor. Although crimes may be torts, the cause of legal action in civil torts is not necessarily the result of criminal action; the harm in civil torts may be due to negligence, which does not amount to criminal negligence. The victim of the harm can recover their loss as damages in a lawsuit. To prevail, the plaintiff in the lawsuit, commonly referred to as the injured party, must show that the actions or lack of action was the legally recognizable cause of the harm. The equivalent of tort in civil law jurisdictions is "delict". Moreover, Tort law differs from Criminal law, whilst both contain punitive elements, Tort law is known to be more vindicatory and 'compensatory' by nature. 'The overall object of tort law is to define cases in which the law may justly hold one party liable to compensate another.'

Legal injuries are not limited to physical injuries and may include emotional, economic, or reputational injuries as well as violations of privacy, property, or constitutional rights. Torts comprise such varied topics as automobile accidents, false imprisonment, defamation, product liability, copyright infringement, and environmental pollution (toxic torts).

Compared to criminal cases, tort lawsuits have a lower burden of proof, namely "preponderance of evidence", rather than beyond a reasonable doubt. Sometimes a claimant may prevail in a tort case even if the defendant who allegedly caused harm were acquitted in an earlier criminal trial. For example, O J Simpson was acquitted in criminal court of murder but later found liable for the tort of wrongful death.

Both tort law and criminal law may impose liability where there is:

 intentional action. reckless behavior. Carelessness. product liability (without negligence) in the US & the EU. "innocence" (or blameless inadvertence) provided there is strict liability. Battery. Assault. Trespass.

Both laws also deter certain types of undesirable behavior through liability. However, in Criminal law the term 'guilty' is used whereas in Tort law this is not the case and 'liable' is used instead.