Thappad is a relationship story of Amrita (Taapsee Pannu) who stays with her husband in a joint family, plays the perfect dedicated homemaker, and manages all the daily household chores. All seems well until one day a slap by her husband during a party in front of all shatters her. The slap makes Amrita think whether a slap is enough to question what a relationship stands for? She takes a stand and files a petition against the humiliation she had to face. On receiving the court order, her husband and his family go against her but she goes all out to regain her self-respect and prove that a Thappad is not 'Bas Itni Si Baat'?