Even those that play a lot of games, or go through university courses, miss the fact that games comprise of a set of standard elements: title screens, training levels, an off button for the music, and so on. We expect them to exist, and barely notice them as we click Next, Next, Next in our effort to get into the game. So while the presence of such items is taken for granted, their omission is enough to cause quizzical and distracting thoughts for the player. In this chapter, we create a checklist of every element that needs to exist and what it should contain. The precise methods by which this can be achieved are covered in the later chapters, categorized by discipline.