Section 287: Self‐defence against provoked assault

When a person has unlawfully assaulted another or has provoked an assault from
another, and that other assaults him with such violence as to cause reasonable
apprehension of death or grievous harm, and to induce him to believe, on reasonable
grounds, that it is necessary for his preservation from death or grievous harm to use
force in self‐defence, he is not criminally responsible for using any such force as is
reasonably necessary for such preservation, although such force may cause death or
grievous harm.
This protection does not extend to a case in which the person using force, which
causes death or grievous harm, first began the assault with intent to kill or to do
grievous harm to some person; nor to a case in which the person using force which
causes death or grievous harm endeavoured to kill or to do grievous harm to some
person before the necessity of so preserving himself arose; nor, in either case, unless,
before such necessity arose, the person using such force declined further conflict, and
quitted it or retreated from it as far as was practicable.