Laws against child sexual abuse vary by country based on the local definition of who is a child and what constitutes child sexual abuse. Most countries in the world employ some form of age of consent, with sexual contact with an underage person being criminally penalized. As the age of consent to sexual behaviour varies from country to country, so too do definitions of child sexual abuse. An adult's sexual intercourse with a minor below the legal age of consent may sometimes be referred to as statutory rape, based on the principle that any apparent consent by a minor could not be considered legal consent.