It is a criminal offense to use or operate a motor vehicle, boat, airplane, motorcycle, or other motor-propelled vehicle without the consent of the owner or other person authorized to give consent. This crime is generally known as (1) unauthorized use of a motor vehicle, (2) unauthorized use of a vehicle, or (3) joyriding.

The difference between this crime and the crime of theft is that the state does not have to prove a person charged with unauthorized use of a motor vehicle intended to keep the vehicle or permanently deprive the owner of the vehicle.

Laws regarding the unauthorized use of a motor vehicle vary from state to state and are generally found in a state’s statutes—often in the penal or criminal code or the vehicle code.

In Missouri, the unauthorized use of a motor vehicle, often referred to as 'joyriding,' is a criminal offense. This crime is distinct from theft or grand theft auto in that the prosecution does not need to prove an intent to permanently deprive the owner of the vehicle. Instead, it is sufficient to show that the individual used or operated the vehicle without the consent of the owner or a person authorized to give consent. Missouri's statutes classify this offense under tampering with a motor vehicle. According to Missouri Revised Statutes Section 569.080, tampering with a motor vehicle in the first degree, which includes the unauthorized use of any motor-propelled vehicle, is a Class D felony. If the use does not involve the elements that would elevate the crime to first-degree tampering, such as causing damage to the vehicle or endangering others, it may be charged as second-degree tampering, which is a misdemeanor. The specific charges and penalties can vary based on the circumstances of the unauthorized use and any prior criminal history of the accused.