In most states it is a criminal offense (statutory rape) to have sexual intercourse with a person under the age of consent—which is usually between 16 and 18 years of age. These laws are premised on the belief that a person under the age of consent is not capable of giving informed consent to sexual intercourse—even if the person was a willing participant.

Statutory rape may be prosecuted as a misdemeanor offense or as a felony offense—depending on the state’s laws and the ages and circumstances of the sexual activity. Statutory rape laws are generally located in a state’s statutes—often in the penal or criminal code.

But many states recognize a defense to such a criminal offense if the persons engaged in the sexual activity were close in age—within three years, for example—provided the persons were at least 14 years of age, for example. These laws are sometimes called Romeo-and-Juliet laws, and are generally located in a state’s statutes—often in the penal or criminal code.

In New Hampshire, the age of consent is 16 years old, as per the state's statutory rape laws. This means that any sexual intercourse with a person under the age of 16 is considered a criminal offense, regardless of whether the minor appeared to be a willing participant, because the law presumes that individuals under this age cannot give informed consent. The severity of the charges can vary from a misdemeanor to a felony, depending on factors such as the ages of the individuals involved and the specific circumstances of the act. New Hampshire does have a 'close-in-age' exemption, commonly referred to as a Romeo-and-Juliet law, which provides a legal defense for individuals who are close in age to the minor involved in the sexual act. This exemption typically applies when the individuals are within a certain age range of each other, which helps to prevent the prosecution of consensual sexual activities among peers. However, the exact provisions and limitations of this exemption can be complex and are detailed within the state's criminal statutes.