We live in a world defined by materials. Man lived through the Stone Age, the Bronze Age, the Iron Age, then the Silicon Age. The availability of critical materials has always defined our societies. Access to a special material, through pure luck or by good planning, has often made the difference between win or lose, life or death, or simply comfort or hardship. In the following pages are shown examples where the availability of critical materials has determined how things turn out: these have been the nails that saved or lost the kingdom. This short book describes a dozen or so cases where availability, accident or luck has led to a new material. Each example is discussed in a few short pages to make for easy reading, but also to teach a little of the basics of the science of the materials. In the past, materials have often been discovered simply because they were available - the earth had somehow created and offered them - and all that had to be done was to realize how useful they could be. Man now thinks himself so clever that he invents new materials - he is so clever. Often, however, his cleverness depends on simple luck (or serendipity), or simple accident, and it is really a question of being in the right place at the right time. Instead of being the clever person that discovers what he is looking for, he is really the lumbering creature whose only merit is to notice what falls into his lap by accident.