To revenge, or to take revenge means to inflict a punishment against someone or a group (an institution...) in return for a damage, an injury or a wrong. The noun “revenge” is synonymous with “vengeance”. In other words, a revenge is a two stages action: prior to the revenge, a person has been harmed by another person. The damage done is great enough to cause the “victim” to hit back, usually by using equal or greater means.

Different degrees of revenge: minor revenges, for minor deeds. Let's say you dumped your girlfriend. Of course she's on the verge of oblivion, and you, you tell everybody how she used to fart in bed. She's pissed off. She feels humiliated. The only way she could possibly feel alright again, would be by bringing you down completely. How? Either by revealing something as embarrassing as what you said, or by telling....

This little story is actually harmless. But when the harmful action deals with a crime, a theft, or any other actions that are deemed against the law, revenge may turn into a real nightmare. In our society, you cannot punish an individual who infringed the law. Only the judicial systems have the authority and legitimacy to do so. You cannot take the law into your own hands for several reasons. The main one is because someone who is obsessed with the idea of revenge will not be impartial. Indeed, if you feel like turning the tables on someone, there's every chance that you make something as bad as what has just been done to you.

Besides, in sports, a revenge is the opportunity for a team that was defeated by another team in the event of a previous match, to retaliate in a return game. In that case a revenge is a fair-play act.