New York State allows individuals to defend themselves against an attack. This is commonly called the right of self defense, but in New York, it is legally know as justification. While there is always a right to defend yourself against an attacker, the law does not allow the use of deadly physical force for self defense in all situations. Deadly physical force is permitted to defend against a person he or she reasonably believes is about to use deadly physical force against him/her or is committing or attempting to commit a kidnapping, forcible rape, forcible sodomy, or robbery. Importantly, there is both a subjective and an objective element. For a person to be allowed to use deadly physical force against another person, that person must believe that the attacker is using or is about to use deadly physical force against him/her or is committing or is about to commit one of the specified criminal acts against him/her, and his/her belief must be reasonable.
It is not enough for a person simply to believe he or she is being subjected to the sort of attack which justifies deadly physical force. His or her belief must be that of a reasonable man or woman in his or her position. This was the holding in the notorious case of People v. Goetz. In Goetz, Bernhard Goetz, a white man, was approached by four young black men, two of whom asked for five dollars, and then shot each of the four young men, severely injuring one of them. Two lower courts dismissed the indictments against Mr. Goetz, but New York's Court of Appeals reinstated them, rejecting the view that the use of deadly physical force was justified if the person using that force believed himself to be in imminent danger. The Court of Appeals ruled that in addition to the subjective belief, the belief had to be reasonable.
One way in which the law of self defense is different in New York than in some other states is that New York is not a "stand your ground" state. If you are attacked outside of your home, the common law requires you to retreat, if this can be done safely. This is the law in New York. Some states, Florida being one of them, do not impose a duty to retreat. The policy behind the duty to retreat is avoiding unnecessary loss of life. Importantly, there has never been a duty to retreat in one's own home. This is because of the "castle doctrine," the idea that one's home is one's refuge of last resort and nobody should be expected to have to retreat from his/her own home. In my view, "stand your ground" is misguided since it does not attempt to prevent deadly conflicts. The traditional and New York view is, in my view, better public policy.