Related Rule
New Zealand
Practice Relating to Rule 155. Defence of Superior Orders
New Zealand’s Military Manual (1992) states: “It is no defence to a war crimes charge that the act was committed in compliance with an order.” 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1710(1).
The manual further states:
An act which is performed in compliance with an unlawful order which, to a reasonable member of the armed forces in the circumstances prevailing at the time of the order, is obviously, palpably or manifestly unlawful, does not constitute a defence to a war crimes charge: nor can it be pleaded in mitigation of punishment. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1710(2).
The manual then states:
If the order involves the commission of an act which is unlawful, though not manifestly so, the fact that it was committed in compliance with an order may be taken into consideration for the purpose of mitigation of punishment. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 1710(3).
The manual adds:
If it is obvious that an order is unlawful, then it should not be obeyed. Orders which are obviously unlawful are extremely rare. An order to torture or kill prisoners of war or innocent civilians or to loot civilian property would be obviously unlawful. This kind of order should never be obeyed and it should never be assumed that it will provide a defence if a charge results from its obedience. 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, Annex C, § C14(4).
In one of its annexes, the manual also states: “If a command is unlawful and is obeyed, the person who obeys it could find himself charged with a criminal offence or a war crime.” 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, Annex C, § C14(2).