Most states make it 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.

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 usually located in a state’s statutes, in the penal or criminal code.

In Illinois, the age of consent is 17 years old, meaning that engaging in sexual activity with someone under this age may constitute statutory rape. Illinois law recognizes statutory rape as a criminal offense, which can be charged as either a misdemeanor or a felony, depending on the circumstances, such as the age difference between the parties and whether force or coercion was involved. Illinois does have a 'Romeo and Juliet' law, which provides a defense in situations where the individuals involved are close in age. Specifically, if the accused is under 17 years old and the sexual partner is less than five years older than the minor, this may serve as a defense against charges of statutory rape. However, this defense is not applicable if the accused is 17 years of age or older. It's important to note that even with the 'Romeo and Juliet' law, sexual activity with someone under the age of consent can still lead to serious legal consequences, and an attorney should be consulted for specific legal advice in such cases.