Private defence, which is commonly and more narrowly referred to as self-defence, is probably the first type of defence you will come across in your life, whether it be defending yourself against bullies in school or elsewhere later in life. In South African law, though, the issue of private defence is still a contentious matter.
Private defence can be referred to as the protection of your own or another person’s interests, including inter alia a life, bodily integrity and property. As is the case with most legislation and legal principles, there is no cut and paste approach concerning private defence and every case is decided on its own merits.
Private defence is defined by C.R. Snyman as follows: “A person acts in private defence, and her act is therefore lawful, if she uses force to repel an unlawful attack which has commenced or is imminently threatening upon her or somebody else’s life, bodily integrity, property or other interest which deserves to be protected, provided that the defensive act is necessary to protect the interest threatened, is directed against the attacker, and is reasonably proportionate to the attack”. 
This definition has been implemented by our courts in an attempt to develop this area of law, and in the process a set of requirements was established in respect of private defence.
The requirements for the defence of private defence are the following:
(a) It must be directed against the attacker.
(b) The defensive act must be necessary. Here one considers whether there is a duty to flee, and whether the defensive act is the only way in which the attacked party can avert the threat to his/her rights or interests.
(c) There must be a reasonable relationship between the attack and the defensive act. Here it is not necessary that there be a proportional relationship between the nature of the interest threatened and the nature of the interest impaired.
(d) The attacked person must be aware of the fact that he/she is acting in private defence. 
The court will consider the above factors in every case where a person is relying on private defence. The factors that could potentially be subjected to the most scrutiny by the courts are firstly, the presence of an imminent attack, and secondly, the proportionality of the defensive act as opposed to the attack.
In the first instance, the courts will consider if the attack had already commenced and whether the act of defence was executed while the attack was still in motion. Only then will this requirement be met. An act of retaliation or vengeance after the initial attack came to an end will generally not be considered by our courts as an act of self-defence.
Additionally, the act of self-defence should be proportional to that of the attack. It would be challenging to convince a court that a person who fatally shot an unarmed attacker after being slapped acted out of self-defence.
However, even though the requirements of private defence might make the defence seem unnecessarily complicated, the courts will apply a robust approach to each set of facts as opposed to clinically over-analysing self-defence acts after the fact.
The test for private defence is objective, with consideration to whether the reasonable man in the position of the accused would have acted in the same way.
The difference between criminal and civil law:
Private defence in criminal and civil matters are different in the following aspects:
In criminal cases the accused’s guilt has to be proven beyond reasonable doubt while at the same time his/her version is weighed up to be reasonably true; In civil matters, where, for example, a claim for damages due to an assault where the defendant is pleading self-defence, the burden of proof is based on the balance of probabilities. This means that the party in the dispute whose evidentiary proof weighs more could tip the scale in his/her favour since that version is more probable.
Even though the same rules might apply in terms of the requirements of self-defence, the burden of proof to convict an accused party who is pleading self-defence could possibly weigh heavier on the party seeking the conviction in a criminal matter.
Though private defence is a necessary defence that we need when living in this beautiful country with its unfortunately high crime rate, it remains a very uncertain defence. Whether the requirements for the successful pleading of the defence are met can only be determined after the fact and on the merits of each case individually, since the need for self-defence mostly occurs in circumstances where the rational consideration of your actions is a luxury that you generally would not have at your disposal.
 Criminal Law Sixth Edition at page 102
 Nene v S (AR65/2017)  ZAKZPHC 46 (4 May 2018)
 S v Ntuli 1975 (1) SA 429 (AD)
This article is a general information sheet and should not be used or relied on as legal or other professional advice. No liability can be accepted for any errors or omissions nor for any loss or damage arising from reliance upon any information herein. Always contact your adviser for specific and detailed advice. Errors and omissions excepted (E&OE)