Revenge is a form of justice usually assumed to be enacted in the absence of the norms of formal law and jurisprudence. Often, revenge is defined as being a harmful action against a person or group in response to a grievance, be it real or perceived. It is used to right a wrong by going outside of the law. This is because the individual taking revenge feels as though the law will not do justice. Revenge is also known as payback, retribution, retaliation, or vengeance; it may be characterized as a form of justice (not to be confused with retributive justice), an altruistic action which enforces societal or moral justice aside from the legal system. Francis Bacon described it as a kind of "wild justice" that "does... offend the law [and] putteth the law out of office". Primitive justice or retributive justice is often differentiated from more formal and refined forms of justice such as distributive justice and divine judgment.
Detractors argue that revenge is simply wrong, of the same design as "two wrongs make a right".
Social psychologist Ian Mckee states that the desire for the sustenance of power motivates vengeful behavior as a means of impression management: "People who are more vengeful tend to be those who are motivated by power, by authority and by the desire for status. They don't want to lose face".
Some societies encourage vengeful behavior, which is called feud. These societies usually regard the honor of individuals and groups as of central importance. Thus, while protecting of his reputation an avenger feels as if he restores the previous state of dignity and justice. According to Michael Ignatieff, "revenge is a profound moral desire to keep faith with the dead, to honor their memory by taking up their cause where they left off". Thus, honor may become a heritage that passes from generation to generation. Whenever it is compromised, the affected family or community members might feel compelled to retaliate against an offender to restore the initial "balance of honor" that preceded the perceived injury. This cycle of honor might expand by bringing the family members and then the entire community of the new victim into the brand-new cycle of revenge that may pervade generations.