A non-aggression pact (abbreviated NAP) is a mutual affirmation of the sovereignty of participant states; in essence, two players promise not to attack each other. In games featuring a casus belli system, violation of a non-aggression treaty can invoke instability or other penalites within the aggressor state. In strictly roleplay-based games, such a treaty is effectively worthless, although breaking it can lower one's reputation among other players and non-player countries.

Because they are frequently non-binding, non-aggression pacts are typically the most-spammed treaty after trade agreements, but serve as the foundation for more permanent mutual protection pacts.