N.H. R. Cir. Ct. Prob. Div. 27
Whenever a third Party is, or may be, liable to a Respondent in any pending action for all or part of the Petitioner's claim against said Respondent or if said Respondent may have a claim against a third Party, depending upon the determination of an issue or issues in the pending action, the Respondent may bring an action against the third Party and, unless otherwise ordered on Motion of any Party, such action shall be consolidated for hearing with the pending action or, if justice requires, on such Motion said third Party may be made a Party to the pending action, for the purpose of being bound by the determination of any common issues; provided, however, that, except for good cause shown to prevent injustice and upon such terms as the Court may order, no such action shall be consolidated with or said third Party joined in said pending action, unless suit is brought against said third Party within sixty (60) days following the Return Day of said pending action.
A third Party against whom an action is brought in accordance with this Rule and a Petitioner against whom a counterclaim has been filed may, under the same circumstances prescribed by this Rule, use the same procedure with respect to another Person and the same time limitation shall apply, except that as to a Petitioner the sixty (60) days shall begin to run on the date the counterclaim is filed.
All existing rules and practices shall apply to actions commenced under this Rule.
This Rule shall not be construed to limit or abridge in any way the existing common law practice of joining Parties in pending actions whenever justice and convenience require, or the giving of notice to third Parties to come in and defend any pending action or be bound by the outcome thereof.
N.H. R. Cir. Ct. Prob. Div. 27