In some countries, you can't use a gun in your own home to defend yourself.

In Poland, apart from it being very difficult to be a gun owner, there is that rule of having to use just enough force to defend yourself. Which is of course very tricky, because if you use "excessive" force you are the aggressor, and your attacker becomes victim: if he had a knife, you'd better use bare hands to defend yourself, etc. In my opinion it's one of the laws that just add insult to injury...