N.H. Rev. Stat. § 498:1
The superior court shall have the powers of a court of equity in the following cases: charitable uses; trusts other than those trusts described in RSA 564-B, over which the probate court has exclusive jurisdiction as provided in RSA 547:3, I(c) and (d); fraud, accident and mistake; the affairs of partners, joint tenants or owners and tenants in common; the redemption and foreclosure of mortgages; contribution; waste and nuisance; the specific performance of contracts; discovery; cases in which there is not a plain, adequate and complete remedy at law; and in all other cases cognizable in a court of equity, except that the court of probate shall have exclusive jurisdiction over equitable matters arising under its subject matter jurisdiction authority in RSA 547, RSA 547-C and RSA 552:7.
RSA 498:1
RS 171:6. CS 181:9. 1855, 1659:12. GS 190:1. GL 209:1. 1885, 87:1. 1887, 77:2. PS 205:1. PL 317 :1. RL 371:1. RSA 498:1. 1971, 179:9. 1992, 284:24. 2006, 91 : 1 , eff. May 5, 2006.