In law, provocation is when a person is considered to have committed a criminal act partly because of a preceding set of events that might cause a reasonable individual to lose self control. This makes them less morally culpable than if the act was premeditated (pre-planned) and done out of pure malice (malice aforethought). It "affects the quality of the actor's state of mind as an indicator of moral blameworthiness."

Provocation is often a mitigating factor in sentencing. It rarely serves as a legal defense, meaning it does not stop the defendant from being guilty of the crime. It may, however, lead to a lesser punishment. In some common law legal systems, provocation is a "partial defense" for murder charges, which can result in the offense being classified as the lesser offense of manslaughter, specifically voluntary manslaughter.

Provocation is distinct from self-defense in that self-defense is a legal defense, and refers to a justifiable action to protect oneself from imminent violence.

Definition.

If a crime is caused by provocation, it is said to be committed in the heat of passion, under an irresistible urge incited by the provoking events, and without being entirely determined by reason. "'Malice aforethought' implies a mind under the sway of reason, whereas 'passion' whilst it does not imply a dethronement of reason, is the furor brevis, which renders a man deaf to the voice of reason so that, although the act was intentional to death, it was not the result of malignity of heart, but imputable to human infirmity. Passion and malice are, therefore, inconsistent motive powers, and hence an act which proceeds from the one, cannot also proceed from the other." (Hannah v Commonwealth, Supreme Court of Virginia 1929) Establishing Provocation can reduce a murder charge to a voluntary manslaughter charge.

Provocation may be defined by statutory law, by common law, or some combination. It is a possible defense for the person provoked, or a possible criminal act by the one who caused the provocation. It may be a defense by excuse or exculpation alleging a sudden or temporary loss of control (a permanent loss of control is regarded as insanity) as a response to another's provocative conduct sufficient to justify an acquittal, a mitigated sentence or a conviction for a lesser charge. Provocation can be a relevant factor in a court's assessment of a defendant's mens rea, intention, or state of mind, at the time of an act which the defendant is accused of.

In common law, provocation is established by establishing events that would be "adequate" to create a heat of passion in a reasonable person, and by establishing that the heat of passion was created in the accused.

The defense of provocation was first developed in English courts in the 16th and 17th centuries. During that period, a conviction of murder carried a mandatory death sentence. This inspired the need for a lesser offense. At that time, not only was it acceptable, but it was socially required that a man respond with controlled violence if his honor or dignity were insulted or threatened. It was therefore considered understandable that sometimes the violence might be excessive and end with a killing.

During the 19th century, as social norms began changing, the idea that it was desirable for dignified men to respond with violence when they were insulted or ridiculed began losing traction and was replaced with the view that while those responses may not be ideal, that they were a normal human reaction resulting from a loss of self-control, and, as such, they deserved to be considered as a mitigating circumstance.

During the end of the 20th century and the beginning of the 21st century, the defense of provocation, and the situations in which it should apply, have led to significant controversies, with many condemning the concept as an anachronism, arguing that it contradicts contemporary social norms where people are expected to control their behavior, even when angry.