Story Shapes is a term used to describe the structure of a story. It is based on the idea that stories have a beginning, middle, and end, and that each part of the story has its own shape. The term ARCS is used to refer to the three parts of a story: Action, Reaction, and Change. Action is the beginning of the story, where the characters and plot are introduced. Reaction is the middle of the story, where the characters and plot develop and move forward. Change is the end of the story, where the characters and plot reach a resolution. Together, these three parts form the Story Shapes.