Rugby knock on is a rule violation in rugby union and rugby league, where a player makes contact with the ball and the ball then goes forwards, or the player loses possession of it. It is considered a turnover, meaning that the team that committed the knock on loses possession of the ball. The knock on can be unintentional, such as when a player loses control of the ball, or intentional, such as when a player throws the ball forwards in an attempt to keep possession. The referee will call a knock on if they believe that the ball has been handled in a manner that is against the rules. The penalty for a knock on is usually a scrum awarded to the opposing team.