Entrapment is a practice in which a law enforcement agent or agent of the state induces a person to commit a "crime" that the person would have otherwise been unlikely or unwilling to commit. It "is the conception and planning of an offense by an officer or agent, and the procurement of its commission by one who would not have perpetrated it except for the trickery, persuasion or fraud of the officer or state agent".

Police conduct rising to the level of entrapment is broadly discouraged and thus, in many jurisdictions, is available as a defense against criminal liability. Sting operations, through which police officers or agents engage in deception to try to catch persons who are committing crimes, raise concerns about possible entrapment.

Depending on the law in the jurisdiction, the prosecution may be required to prove beyond a reasonable doubt that the defendant was not entrapped or the defendant may be required to prove that they were entrapped as an affirmative defense.

In the practice of journalism and whistle-blowing entrapment means "deceptive and trust-breaking techniques ... applied to trick someone to commit a legal or moral transgression."

United States.

In the United States, two competing tests exist for determining whether entrapment has taken place, known as the "subjective" and "objective" tests.

The "subjective" test looks at the defendant's state of mind; entrapment can be claimed if the defendant had no "predisposition" to commit the crime.

The "objective" test looks instead at the government's conduct; entrapment occurs when the actions of government officers would usually have caused a normally law-abiding person to commit a crime.

Contrary to popular belief, the United States does not require police officers to identify themselves as police in the case of a sting or other undercover work, and police officers may lie when engaged in such work. The law of entrapment instead focuses on whether people were enticed to commit crimes they would not have otherwise considered in the normal course of events.