S.C. Code Ann. § 50-26-20: All-terrain vehicle (ATV) defined.

For the purposes of this chapter, "all-terrain vehicle" or "ATV" means a motorized vehicle designed primarily for off-road travel on low-pressure tires which has three or more wheels and handle bars for steering, but does not include lawn tractors, battery-powered children's toys, or a vehicle that is required to be licensed or titled for highway use. The term "ATV" includes Type I-single passenger all-terrain vehicles and Type II-tandem passenger all-terrain vehicles.