A character arc is the transformation or inner journey of a character over the course of a story. If a story has a character arc, the character begins as one sort of person and gradually transforms into a different sort of person in response to changing developments in the story. Since the change is often substantive and in the opposite direction, the geometric term arc is often used to describe the sweeping change. In most stories, lead characters and protagonists are the characters most likely to experience character arcs, although it is possible for lesser characters to change as well. A driving element of the plots of many stories is that the main character seems initially unable to overcome opposing forces, possibly because he or she lacks skills or knowledge or resources or friends.