The rules of cricket
Law 36 (Leg before wicket)
1. Out LBW
The striker is out LBW in the circumstances set out below.
(a)The bowler delivers a ball, not being a No ball
and (b) the ball, if it is not intercepted full pitch, pitches in line between wicket and wicket or on the off side of the striker's wicket
and (c) the ball not having previously touched his bat, the striker intercepts the ball, either full pitch or after pitching, with any part of his person
and (d) the point of impact, even if above the level of the bails
either (i) is between wicket and wicket
or (ii) is either between wicket and wicket or outside the line of the off stump, if the striker has made no genuine attempt to play the ball with his bat
and (e) but for the interception, the ball would have hit the wicket.
2. Interception of the ball
(a) In assessing points (c), (d) and (e) in 1 above, only the first interception is to be considered.
(b) In assessing point (e) in 1 above, it is to be assumed that the path of the ball before interception would have continued after interception, irrespective of whether the ball might have pitched subsequently or not.
3. Off side of wicket
The off side of the striker's wicket shall be determined by the striker's stance at the moment the ball comes into play for that delivery.