he development of the first suit of advanced power armor, designated X-01, began shortly before the Great War. The first test batch of the armor, designated X-01 Mk I, was developed for presidential bodyguards, and served as the baseline for the remnants of the United States military, who developed it into a power armor tailored for the post-War wasteland. It represented a radical, new approach to designing powered armor, eschewing traditional armor design philosophies, but was never deployed in larger quantities until the 23rd century. Work on the model was restarted by the Enclave in 2198, although it wasn't until 2215 that the research efforts began in earnest under a presidential mandate, with the first production model created in 2220.

The X-01 advanced powered infantry combat armor is designed for a single human operator, provided with the comfort and protection of a next-generation suit of armor. While the T-51 power armor relied on a lightweight poly-laminateceramic castings at key points. The resulting space savings allowed for reducing the armor's profile without compromising protection. Classic power armor pauldrons were retired in favor of a hump that encloses the operator's head, significantly reducing the chance of enemy fire damaging the vital areas surrounding the head. Perhaps the most noticeable change was a completely new helmet assembly. The unusual, insect-like design features a pair of polarized eyepieces in place of the usual vision slit, providing superior battlefield awareness. Its angled surfaces also help maximize the chance of outright deflecting projectiles and incoming fire. composite shell for protection, the advanced model uses lightweight metal alloys as a basis, reinforced with




The Nuka-Cola Corporation had strong ties with the U.S. military which allowed them access to their technology, including suits of power armor. The suits were given Nuka-Cola themed paint jobs and used to promote the soft drink. Vim! Pop Incorporated had a similar idea by using a suit of their own and giving it a Vim! inspired paint scheme to promote their drink.