In rugby, a knock-on occurs when a player, while in possession of the ball or attempting to catch it, makes contact with the ball and the ball goes forward. This can happen when a player fails to catch or pick up a ball that has been passed cleanly, causing it to travel forward off their hand or arm and hit the ground or another player. If a player manages to catch the ball before it hits the ground, it is not considered a knock-on.
A knock-on can result in a scrum being awarded to the opposing team, with the team that committed the knock-on losing possession of the ball. However, if a player accidentally knocks on the ball and then regains or kicks it before it touches the ground, a goal post, crossbar, or another player, play may continue without a scrum being awarded.
