Design in the 21st century has become increasingly more embedded in a complex system of disciplines (software and digital design, graphic design, architecture, construction, medical practices, business design and management, technology, graphic design, product design, etc.) and as a result, the intricacies of designing a product have increased. How can NASA test products for alien environments on Earth? How can a designer successfully test a digital program for a space that is not tangible? It is these problems that this collection responds to, allowing the reader to understand the significance of the prototype in modern design, and how designers must use this process to predict the potential future of their product. Prototype enables design students and professionals to explore the significance of the prototype and its influence and bearing on the future of design. As the prototype is a model of something not yet built, a kind of future in the present, its importance in the development of the finished product cannot be ignored. It allows designers to understand what needs to be changed and what needs to be manipulated in order to create a product that successfully understands and navigates all the complexities of the modern world. In this way, the book allows us to rethink the nature of the prototype for the 21st century and beyond.