Thing about the Restatement (any of 'em) is that they must be read carefully, being especially wary of circularity. Note here that the actor would be privileged only to the extent he would be privileged, get it? under some other body of law not specifically referenced. So it all comes back to reasonable apprehension of bodily harm to yourself or your family (or guests, I suppose), in your home or similar place. MacN On Wed, 6 Sep 1995, Black Unicorn wrote:
The basic rule today in most states resembles the restatement position:
Section 85. Use of Mechanical Device Threatening Death or Serious Bodily Injury.
The actor is so far privileged to use such a device intended or likely to cause serious bodily harm or death for the purpose of protecting his land or chattels from intrusion that he is not liable for the serious bodily harm or death thereby caused to an intruder whose intrusion is, in fact, such that the actor, were he present, would be privileged to prevent or terminate it by the intentional infliction of such harm.
[big snip of excellent research]