High-energy density materials (HEDMs) continue to attract significant interest as their capacity for rapid and immense energy release makes them particularly well-suited for explosives, propellants, and pyrotechnics. While conventional HEDMs such as TNT and RDX provide rich reservoirs of energy at established industrial scales, their performance is approaching its theoretical ceiling, coupled with persistent concerns over safety and undesirable environmental byproducts. Consequently, highly nitrogen rich compounds have emerged as a tantalizing frontier in HEDM development, offering enhanced energetic performance with nitrogen gas as a benign decomposition product. This emergent field is explored through both conventional synthetic procedures as well as high-pressure, high-temperature synthesis in diamond anvil cells. These approaches illustrate the rapidly expanding landscape of nitrogen-rich materials and the opportunities that synthesis under extreme conditions present for future HEDM development.