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 Delaware, unauthorized use of a vehicle, commonly referred to as 'joyriding,' is addressed under Title 11, Section 840 of the Delaware Code. This statute makes it a criminal offense to knowingly take, operate, or exercise control over a motor vehicle, aircraft, or vessel without the consent of the owner. The key distinction between this offense and vehicle theft (grand theft auto) is the element of intent. For a charge of unauthorized use, the state does not need to prove that the individual intended to permanently deprive the owner of the vehicle, which is a necessary element for a theft charge. Unauthorized use is considered a less severe offense compared to theft and is often treated as a misdemeanor, but the exact penalties can vary based on the circumstances of the offense and the individual's criminal history.