In addition to providing a valid defense in criminal law, many versions of the Castle Doctrine, particularly those with a "Stand-Your-Ground clause", also have a clause which provides immunity from any lawsuit filed on behalf of the assailant for damages/injury resulting from the use of lethal force. Without this clause, it is possible for an assailant to sue for medical bills, property damage, disability, and pain and suffering as a result of the injuries inflicted by the defender, or for their next-of-kin to sue for wrongful death in the case of a fatality. Even if successfully refuted, the defendant (the homeowner/defender) must often pay thousands of dollars in legal costs as a result of such lawsuits, and thus without immunity, such civil action could be used for revenge against a defender acting lawfully.

The only exceptions to this civil immunity are generally situations of excessive force, where the defender used deadly force on a subdued, cooperative, or disabled assailant. A situation meeting this exception generally invalidates the criminal "castle defense" as well. In addition, someone who uses deadly force in self-defense is still liable for any damages or injuries to third parties who were not acting criminally at the time of the defensive action