In law, fraud is intentional deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud can violate civil law (for example, a fraud victim may sue the fraud perpetrator to avoid the fraud or recover monetary compensation) or criminal law (for example, a fraud perpetrator may be prosecuted and imprisoned by governmental authorities), or it may cause no loss of money, property, or legal right but still be an element of another civil or criminal wrong. The purpose of fraud may be monetary gain or other benefits, for example by obtaining a passport, travel document, or driver's license, or mortgage fraud, where the perpetrator may attempt to qualify for a mortgage by way of false statements.

Internal fraud, also known as "insider fraud", is fraud committed or attempted by someone within an organization such as an employee.

A hoax is a distinct concept that involves deliberate deception without the intention of gain or of materially damaging or depriving a victim.

As a civil wrong.

In common law jurisdictions, as a civil wrong, fraud is a tort. While the precise definitions and requirements of proof vary among jurisdictions, the requisite elements of fraud as a tort generally are the intentional misrepresentation or concealment of an important fact upon which the victim is meant to rely, and in fact does rely, to the harm of the victim. Proving fraud in a court of law is often said to be difficult as the intention to defraud is the key element in question. As such, proving fraud comes with a "greater evidentiary burden than other civil claims". This difficulty is exacerbated by the fact that some jurisdictions require the victim to prove fraud by clear and convincing evidence.

The remedies for fraud may include rescission (for example, reversal) of a fraudulently obtained agreement or transaction, the recovery of a monetary award to compensate for the harm caused, punitive damages to punish or deter the misconduct, and possibly others.

In cases of a fraudulently induced contract, fraud may serve as a defense in a civil action for breach of contract or specific performance of contract. Similarly, fraud may serve as a basis for a court to invoke its equitable jurisdiction.

As a criminal offense.

In common law jurisdictions, as a criminal offense, fraud takes many different forms, some general (for example, theft by false pretense) and some specific to particular categories of victims or misconduct (for example, bank fraud, insurance fraud, forgery). The elements of fraud as a crime similarly vary. The requisite elements of perhaps the most general form of criminal fraud, theft by false pretense, are the intentional deception of a victim by false representation or pretense with the intent of persuading the victim to part with property and with the victim parting with property in reliance on the representation or pretense and with the perpetrator intending to keep the property from the victim.