When an offensive player precedes the puck across the blue line and into the offensive zone. For an off-side violation, a face-off will be conducted in the neutral zone.
Generally when a player is in front of the ball when it was played last by a team member. A penalty occurs if a player is off-side and obstructs an opponent, plays the ball or is within 10 meters (10 yards) of an opponent playing the ball.
Off-side is the most complex law in rugby. Generally, off-side is when a player is in front of the ball in open play, or in front of the hind most foot of the last man in a scrum, ruck or maul. Off-side becomes more complex in line-outs or when kicking. A penalty can occur if a player is off-side.