A knock-on occurs when a player loses possession of the ball and it goes forward, or when a player hits the ball forward with the hand or arm, or when the ball hits the hand or arm and goes forward, and the ball touches the ground or another player before the original player can catch it.
‘Forward’ means towards the opposing team’s dead ball line.
If a player in tackling an opponent makes contact with the ball and the ball goes forward from the ball carrier’s hands, that is a knock-on.
If a player rips the ball or deliberately knocks the ball from an opponent's hands and the ball goes forward from the ball carrier's hands, that is not a knock-on.
Charge down. If a player charges down the ball as an opponent kicks it, or immediately after the kick, it is not a knock-on even though the ball may travel forward.
Definition: Throw forward
A throw forward occurs when a player throws or passes the ball forward, i.e, if the arms of the player passing the ball move towards the opposing team’s dead ball line.
Bounce forward. If the ball is not thrown forward but it hits a player or the ground and bounces forward, this is not a throw forward.
12.1 The outcome of a knock-on or throw forward
Unintentional knock-on or throw forward. A scrum is awarded at the place of infringement.
Unintentional knock-on or throw forward at a lineout. A scrum is awarded 15 metres from the touchline.
Knock-on or throw forward into the in-goal. If an attacking player knocks-on or throws-forward in the field of play and the ball goes into the opponents’ in-goal and it is made dead there, a scrum is awarded where the knock-on or throw forward happened.
Knock-on or throw forward inside the in-goal. If a player of either team knocks-on or throws-forward inside the in-goal, a 5-metre scrum is awarded in line with the place of infringement not closer than 5 metres from the touchline.
Knock-on or throw forward into touch. When the ball goes into touch from a knock-on or throw forward, the non-offending team will have the option of a lineout at the point the ball crossed the touch line or a scrum at the place of the knock-on or throw forward, or a quick throw in.
Intentional knock or throw forward. A player must not intentionally knock the ball forward with hand or arm, nor throw forward.
Sanction: Penalty kick. A penalty try must be awarded if the offence prevents a try that would probably otherwise have been scored.