The rules of cricket
Law 30 (Bowled)
1. Out Bowled
(a) The striker is out Bowled if his wicket is put down by a ball delivered by the bowler, not being a No ball, even if it first touches his bat or person.
(b) Notwithstanding (a) above he shall not be out Bowled if before striking the wicket the ball has been in contact with any other player or with an umpire. He will, however, be subject to Laws 33 (Handled the ball), 37 (Obstructing the field), 38 (Run out) and 39 (Stumped).
2. Bowled to take precedence
The striker is out Bowled if his wicket is put down as in 1 above, even though a decision against him for any other method of dismissal would be justified.