The law of self-defence is a legal principle that allows individuals to use reasonable force to protect themselves or others from harm. This principle is rooted in the common law system, which originated in England in the early 1500s and has since been adopted by many countries around the World.

Under common law, self-defence is generally justified when an individual reasonably believes that they or someone else is in imminent danger of bodily harm or death. The force used in self-defence must be proportional to the threat of harm the individual faces. This means that individuals can only use as much force as is necessary to defend themselves and cannot use excessive force or engage in pre-emptive strikes.

In determining whether the use of self-defence was justified, courts will consider several factors, including the nature and severity of the threat faced by the individual, the individual’s ability to safely retreat or de-escalate the situation, and the individual’s level of expertise or training in self-defence techniques. 

A critical aspect of the law of self-defence is the: castle doctrine,” which allows individuals to use deadly force to defend their home or dwelling place. this doctrine is based on the idea that a person’s home is their “castle” and that they have a right to defend it against intruders or attackers. However, this doctrine is limited because it only applies to the individual’s home or dwelling place and does not extend to other locations.

Another critical aspect of the law of self-defence is the “Stand your ground” doctrine, which allows individuals to use deadly force to defend themselves anywhere they have the right to be. This idea is based on the idea that individuals should NOT be required to de-escalate a situation if forced with a threat of harm. However, this doctrine has been controversial in some legal circles and has faced criticism for potentially escalating violent confrontations. Rule of thumb: no matter the place or circumstances  of a self-defence incident, there will be an investigation and eventual legal process. 

 In summary, the law of self-defence is a legal principle that allows individuals to use reasonable force to protect others from harm. It is based on a common law system. It considers several factors, including the nature and severity of the threat faced by the individual, the individual’s ability to safely retreat(as required by law or not) or de-escalate the situation, and the individual’s level of expertise or training in self-defence techniques. While the castle doctrine and stand-your-ground doctrine provide additional protections for individuals in certain circumstances, they are also subject to limitations and controversy in certain legal circles.