What are the general defences or exceptions to liability in a tort?

General defences are the rules of immunity which limit the rules of liability in tort. These are various conditions which, when present, will prevent an act from being wrongful which in their absence would be a wrong. Some of the general defences are mentioned below.

Volenti non fit  injuria – Leave and License : A man cannot complain of harm to the chances of which he has exposed himself with knowledge and of his free will.

Act of God: Those act which are occasioned by the elementary forces of nature unconnected with the agency of man or other cause.

Inevitable Accident: An accident which could not possibly be prevented by the exercise of ordinary care, caution and skill.

Act of State: It is an exercise of sovereign power as matter of policy or political expediency. An act of state is not available against a citizen. In Civil commotion, or even in war or peace, the State cannot act catastrophically outside the ordinary law ad there is legal remedy for its wrongful acts against its own subject or even a friendly alien within the State.

Private Defence: Every person has a right to defend his own person, property, possession, against an unlawful harm.

Other general defences are mistake, statutory authority, damage incident to authorized acts,  necessity,  plaintiff a wrongdoer, exercise of common rights, Duress judicial and quasi-judicial acts, parental and quasi-judicial act, executive acts, and  contributory negligence.