Vengeance is the act of harming someone in return for harm they caused you. It's driven by a desire to make someone suffer because they made you suffer first. When someone seeks vengeance, they want to hurt the person who hurt them, to even the score or make things feel fair again.

Vengeance differs from justice. Justice follows rules and aims to be fair and proportional: if someone steals your lunch, a just consequence might be that they apologize and replace it. Vengeance focuses on payback: you might want to destroy something of theirs or publicly embarrass them. Justice asks, “What's fair?” Vengeance asks, “How can I make them hurt like they hurt me?”

Vengeance can create cycles of retaliation: you hurt someone back, they hurt you again, and it never ends. That's why legal systems exist to handle wrongs through courts and rules rather than personal payback.

The related word avenge means to seek justice or retribution for someone else, rather than for yourself.