The Commando System was a mostly voluntary, part-time force of the South African Army, but in their role as local militia the units were often deployed in support of and under the authority of the South African Police.

South Africa's Commando System was responsible for the safeguarding and protection of specific communities (usually rural, but sometimes urban). Commando units were usually referred to as area protection, a civil defence system which involved the whole community. The participants in the Commando System did not have military commitments outside of the areas they served and were responsible for the safety and security of their own communities.

The Commando system existed from the 1770s. The early Boer Commando system was a conscriptive service designed to provide a quickly-trained fighting force.^{[citation needed]}

Commandos were a product of the First Boer War during which the fiercely independent Boers had no regular army. When danger threatened, all the men in a district would form a militia organised into military units called commandos and would elect officers. Being civilian militia, each man wore what they wished, usually everyday neutral or earthtone khaki farming clothes such as a jacket, trousers and slouch hat. Each man brought his own weapon, usually a hunting rifle, and his own horses. The average Boer citizens who made up their commandos were farmers who had spent almost all their working life in the saddle, and because they had to depend on both their horse and their rifle for almost all of their meat, they were skilled hunters and expert marksmen. Most of the Boers had single-shot breech-loading rifles such as the Westley Richards, the Martini-Henry, or the Remington Rolling Block. Only a few had repeaters like the Winchester or the Swiss Vetterli. As hunters they had learned to fire from cover, from a prone position and to make the first shot count, knowing that if they missed the game would be long gone. At community gatherings, target shooting was a major sport and competitions used targets such as hens eggs perched on posts 100 yards away. The commandos became expert light cavalry, making use of every scrap of cover, from which they could pour an accurate and destructive fire at the British with their breech-loading rifles which could be rapidly aimed, fired, and reloaded.

At least during the Second Boer War each commando was attached to a town, after which it was named (e.g. Bloemfontein Commando). Each town was responsible for a district, divided into wards. The Commando was commanded by a Kommandant and each ward by a Veldkornet or field-cornet - equivalent of a senior NCO rank.

The Veldkornet was responsible not only for calling up the burghers, but also for policing his ward, collecting taxes, issuing firearms and other material in times of war. Theoretically, a ward was divided into corporalships. A corporalship was usually made up of about 20 burghers. Sometimes entire families filled a corporalship.

The Veldkornet was responsible to the Kommandant, who in turn was responsible to a General. In theory, a General was responsible for four commandos. He in turn was responsible to the Commander-in-Chief (CIC) of the Republic. In the Transvaal, the CIC was called the Commandant-General and in the Free State the Hoofdkommandant or Chief Commandant. The CIC was responsible to the President.

Other auxiliary ranks were created in war time, such as Vleiskorporaal ("meat corporal"), responsible for issuing rations.