In a case of extreme necessity everything is common.
In case of extreme compulsion all things are common i.e. public property. In times of crisis/disaster a private property can become a public property and used without liability for trespass.
It is a Latin term which means ‘in case of extreme necessity everything is common.’
In times of war, a house may be pulled down, if the defence of the States so demands.
If a highway is impassable, a person may lawfully use adjoining land.
A person might be unable to understand the maxim without referring to the very celebrated case of R v. Dudley & Stephens. The defendants and a cabin boy were cast adrift in a boat following a shipwreck. The defendants agreed that as the cabin boy was already weak, and looked likely to die soon, they would kill him and eat him for as long as they could, in the hope that they would be rescued before they themselves died of starvation. A few days after the killing they were rescued and then charged with murder. The judges of the Queen’s Bench Division held that the defendants were guilty of murder in killing the cabin boy and stated that their obvious necessity was no defence. The defendants were sentenced to death, but this was commuted to six months’ imprisonment.
Edited by Vigneshwar Ramasubramania
Approved & Published – Sakshi Raje
 R v. Dudley & Stephens, (1884) 14 QBD 273