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 Illinois, the age of consent is 17 years old. This means that it is a criminal offense to have sexual intercourse with someone under the age of 17, even if the individual is a willing participant. This is considered statutory rape. The severity of the offense 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 sexual activity. Illinois does have a 'Romeo and Juliet' law, which provides a defense in situations where the parties are close in age. Specifically, if the accused is under 17 years old and the sexual conduct was consensual, and the two individuals are within 5 years of each other's age, the offense may be reduced from a felony to a misdemeanor. This is codified in the Illinois Criminal Code under Article 11 - Sex Offenses.