Virtually every game can be solved more easily and efficiently by using a diagram. Unless you have a remarkable memory and can process reams of information in your head, you must draw a diagram. Because of the effectiveness of diagrams, games are the best candidates for improvement. A well-constructed diagram can change a convoluted, unwieldy mass of information into an easily read list. In fact, from a well-constructed diagram, you can often read-off the answers without any additional thought. Before we begin studying how to construct diagrams, we need to develop some facility for creating and manipulating symbols.