Related Rule
Practice Relating to Rule 152. Command Responsibility for Orders to Commit War Crimes
Germany’s Military Manual (1992) provides:
Superiors shall only issue orders which are in conformity with international law. A superior who issues an order contrary to international law exposes not only himself but also the subordinate obeying to the risk of being prosecuted. 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 141.
Germany’s Law on the Legal Status of Military Personnel (1995) provides that a superior “may give orders only for official purposes and only in observance of the rules of international public law … He bears responsibility for his orders.” 
Germany, Law on the Legal Status of Military Personnel, 1995, § 10(4) and (5).
Germany’s Penal Code (1998) provides: “Whoever commits the crime himself or through another shall be punished as a perpetrator.” As regards incomplete crimes such as an illegal order given but not carried out by the subordinate, it also states: “An attempt to commit a serious criminal offence is always punishable.” 
Germany, Penal Code, 1998, §§ 23(1) and 25(1).
In its judgment in the Dover Castle case in 1921, the German Reichsgericht held:
It is a military principle that the subordinate is bound to obey the orders of his superiors. This duty of obedience is of considerable importance from the point of view of criminal law. Its consequence is that, when the execution of a service order involves an offence against the criminal law, the superior giving the order is alone responsible. 
Germany, Reichsgericht, Dover Castle case, Judgment, 4 June 1921.
The Report on the Practice of Germany states:
By giving a criminal order, the superior violates his obligations under the [Law on the Legal Status of Military Personnel] … If the order is executed, the superior can be punished for having committed a war crime according to general rules on perpetration as stated in section 25 of the German Penal Code. If the order has not been followed the superior can be punished according to the concept of incomplete crimes … embodied in section 22 of the German Penal Code. 
Report on the Practice of Germany, 1997, Chapter 6.8.