N.H. Rev. Stat. § 627:1-a
A person who uses force in self-protection or in the protection of other persons pursuant to RSA 627:4, in the protection of premises and property pursuant to RSA 627:7 and 627:8, in law enforcement pursuant to RSA 627:5, or in the care or welfare of a minor pursuant to RSA 627:6, is justified in using such force and shall be immune from civil liability for personal injuries sustained by a perpetrator which were caused by the acts or omissions of the person as a result of the use of force. In a civil action initiated by or on behalf of a perpetrator against the person, the court shall award the person reasonable attorney's fees, and costs, including but not limited to, expert witness fees, court costs, and compensation for loss of income.
RSA 627:1-a
2011, 268:3, eff. Nov. 13, 2011.