Related Rule
South Africa
Practice Relating to Rule 145. Reprisals
Section A. Definition and purpose of reprisals
South Africa’s LOAC Manual (1996) states:
A reprisal is an otherwise illegal act in response to a prior illegal act by the enemy. The purpose of a reprisal is to get the enemy to adhere to the law of war. Reprisals are only permitted according to strict criteria. 
South Africa, Presentation on the South African Approach to International Humanitarian Law, Appendix A, Chapter 4: International Humanitarian Law (The Law of Armed Conflict), National Defence Force, 1996, § 34(e).
[emphasis in original]
South Africa’s Revised Civic Education Manual (2004) states:
A reprisal is an otherwise illegal act in response to a prior illegal act by the enemy. The purpose of a reprisal is to get the enemy to adhere to the law of war. Reprisals are only permitted according to strict criteria. 
South Africa, Revised Civic Education Manual, South African National Defence Force, 2004, Chapter 4, § 56(e).
[emphasis in original]
South Africa’s LOAC Teaching Manual (2008) states:
Reprisals
- In general it can be said that it is lawful for States to take reprisal actions, but not for individual soldiers to do so.
- Reprisals are actions which would normally have been unlawful under international law, but which become lawful in order to stop the unlawful act of another Party to the conflict.
- The LOAC [law of armed conflict] prohibits reprisals against the following:
- Civilians, civilian objects and the civilian population;
- POW [prisoners of war];
- Specifically protected persons and objects;
- Objects indispensable for the survival of the civilian population;
- The natural environment.
- Reprisals have been defined as acts of retaliation in the form of conduct which would otherwise be unlawful, taken as a last resort by one Party to the conflict against enemy personnel or property in retort to violations of LOAC committed by the other party for the sole purpose of enforcing future compliance with the rules of the LOAC. [US Army Field Manual FM-2710, paragraph 497, US v Oldendorf, 4 Trials of War Criminals before the Nuremberg Military Tribunals, 493 (1950)].
- Reprisal actions should only be taken if the enemy breach of the LOAC is deliberate and of a serious nature. 
South Africa, Advanced Law of Armed Conflict Teaching Manual, School of Military Justice, 1 April 2008, as amended to 25 October 2013, Learning Unit 3, p. 194.