From science to so-called secret sauces, we will share some of the tricks, techniques, and good practices that go into designing and manufacturing reliable lasers and systems. Lasers are often expensive. Eliminating laser failures, even one laser failure, is a big win. This course examines both optical and non-optical issues that affect reliability. We will emphasize solid-state lasers, frequency-converted lasers, aspects of fiber lasers, and systems that use lasers. We will cover semiconductor lasers, mainly from the perspective of using them as components. Our goal is to help you make more reliable lasers and more reliable laser systems. Together, we will discuss many examples illustrating key failure modes and how to avoid failures.