According to the William and Mary Law Review Vol 42:2 in an article titled “Stand Your Ground” and Self Defense (2015 Cynthia Ward) to advance a claim of self defense you must “(1) be faced with a threat of death or serious bodily injury from the attack; (2) the threatened attack must be “imminent,” in the plain-language sense that it is about to happen right then; and the defendant at that moment must (3) honestly and (4) reasonably believe that the use of deadly force is necessary to prevent
such injury or death” thus preserving your claim that you in fact defended yourself from an imminent threat. You can read all 51 pages in detail here .
Does this apply to your own house? There is case law cited in the same article “In the 1914 New York case People v. Tomlins,12 Justice Benjamin Cardozo explained the basis of this Castle Doctrine”: “It is not now and never has been the law that a man assailed in his own dwelling is bound to retreat … If assailed there, he may stand his ground and resist the attack.” Meaning that if you have a claim of self defense the idea of stand your ground in most states would be determined if you are outside your home, but not all states are like this. I am not a lawyer and I am not giving legal advice so please check the laws in your state to see how that applies, this is a general article about the legal and financial implications of defending yourself. There are other provisions in law about if you defend another person, are the assailants committing a felony that puts life in jeopardy and in some states as we all saw in the Kyle Rittenhouse trial in Wisconsin you cannot protect property with deadly force (which is crazy to think about but still on the books in that state). Further there are also areas where a person could be the aggressor, then retreat and disengage and then the person that they initially went after retaliates and the person starting the issue becomes the victim because they retreated and can then use deadly force to protect themselves. The world is a crazy place and you never know when a simple trip to the store for some groceries or a pack of gum or a can of Copenhagen can result in the death of a human being.