A speedster is a character, primarily in superhero comics, whose powers primarily relate to superhuman speed (also known as superspeed). Primary abilities shared by all speedsters include running at speeds far in excess of human capability (to varying degrees) and resistance to the side effects of such velocities (air resistance, inability to breathe, dynamic shock resulting from contact with objects at high speed, etc.). In almost all cases, speedsters can physically attack opponents by striking them at high speed, imparting great kinetic energy without themselves being harmed or at times even affected at all. A variety of other powers have been attributed to speedsters, depending on the story, their power's origin, and their universe's established continuity and rules.