N.H. Rev. Stat. Ann. § 208:5-a

A person who has complied with the licensing requirements relative to hunting deer pursuant to RSA 214, shall be issued a license, upon payment of a fee set by the executive director pursuant to RSA 206:10, I, for the following categories: residents 16 years of age or older and nonresidents 16 years of age or older. A muzzleloading license shall not be required for residents less than 16 years of age, but such person while hunting with a muzzleloading firearm shall be accompanied by a properly licensed person who is 18 years of age or over and shall also comply with all provisions of this chapter. The license shall entitle the holder to hunt deer with a single shot muzzleloading firearm or with a crossbow.