This section consists of four chapters that relay cases of LX design-in-use. By design-in-use, we refer to the applied use of LX methods and processes to create digital environments for learning. These chapters serve as exemplars on multiple levels. On one level, they represent worked examples that detail the actions, events, rationales, challenges, etc. of LX design from beginning to end. On another level, the chapters are success cases of LX design, highlighting the synergistic interplay of pedagogy and theory with perceptions of usefulness and other hedonic aspects.