Fallout Wiki
Fallout Wiki
Gameplay articles
Fallout 4X-01 power armor
Quantum X-01 power armor Nuka-World (add-on)
Fallout 76X-01 power armor
Fallout ShelterX-01 power armor

X-01 power armor is a prototype model of power armor developed by the United States shortly before the Great War. It was the last and most advanced model of power armor developed before Great War, and serves as the predecessor to all post-War models of advanced power armor used by the Enclave.


Fo4 Power Armor X01

X-01 power armor

Commissioned by the Joint Chiefs of Staff, the development of the X-01 began shortly before the Great War.[1] It represented a radically new approach to designing powered armor, eschewing traditional design philosophies that defined the T series,[Non-game 1] and was a high-profile research project meant to supersede previous power armor models. However, although the suit was technically functional by late 2077, it was burdened with numerous issues that precluded widespread use in the field. A single suit of X-01 was provided to the Nuka-Cola Corporation, as part of Project Cobalt. While the suit served as a successful proof of concept of using a strontium-90 based plating over the armor,[2] this improvement was not adopted into the armor's schematics, before the onset of the Great War. Further development was made impossible due to the outbreak of the Great War.[1]

After the Great War, a select few suits were engineered further and employed by remnants of the U.S. military, like the Enclave and Brotherhood of Steel, as well as the Institute.[3] The schematics for the armor were saved by the Enclave just before the bombs fell, with the organization keeping copies in the archives of their Poseidon and Whitespring facilities, including Control Station ENCLAVE. This allowed the Enclave to create a limited production run of the suits, and for work to eventually continue on the model's development.[1]

Full development was restarted by the Enclave in 2198, although it wasn't until 2215 that the research efforts began in earnest under Presidential mandate, resulting in the creation of the first model of Advanced power armor in 2220.[Non-game 1] Another group to develop upon the X-01 design, after the war, is the Institute. Despite lacking access to the prototype's schematics, by 2287, the Institute had developed a modified polymerized casting mix to coat the armor, as well as other modifications that enhance the user's intelligence.[4]


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-laminate composite shell for protection, the advanced model uses lightweight metal alloys as a basis, reinforced with ceramic castings at key points. The resulting space savings allowed for reducing the armor's profile without compromising protection. 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. The helmet's eyepieces also served as the suit's lamps, replacing the traditional single-lens attachment used in older models. The helmet's angled surfaces also help maximize the chance of outright deflecting projectiles and incoming fire.[5]

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. Despite these advancements, the X-01 suffers from severe design flaws that prevent it from seeing large scale deployment.[1]


Prototype X-01 power armor[]

F76 X01

Prototype X-01 paint scheme

Gameplay articles: Fallout 4, Fallout 76

While all units of X-01 were experimental prototypes, this model represents the earliest functional version of the power armor suit, unfinished before the Great War. The schematics for the armor were saved by the Enclave just before the bombs fell, with the organization keeping copies in the archives of their Poseidon and Whitesprings facilities. This allowed the Enclave a limited production of the suits.

Quantum X-01 power armor[]

FO4 NW Quantum X-01

Quantum X-01

Gameplay article: Fallout 4

Thanks to strong ties with the U.S. military, the Nuka-Cola Corporation managed to secure a suit of the experimental X-01 Mk V armor just prior to the Great War. The company intended to use the armor as part of Project Cobalt, and to help promote their new Nuka-Cola Quantum soft drink. The corporation plated the armor in a compound made with the strontium-90 isotope used in the Quantum soda, allowing the wearer to more rapidly recover after physical exertion. Only one example of this variant was produced before the bombs fell and prevented any further production.

X-01-I power armor[]

Fo4 Institute Paint

X-01-I "Institute Paint" paint scheme

Gameplay article: Fallout 4

Centuries after the Great War, suits of X-01 were found by The Institute around the Commonwealth. The Institute developed a modified polymerized casting mix to coat them with, among other upgrades that improved the intelligence of the wearer.[6]

X-01 MK I/IV/VI power armor[]

FoS X-01 Mk IV power armor

X-01 from Fallout Shelter

Gameplay article: Fallout Shelter

A Variant of X-01 seen in Fallout Shelter, it comes in 3 different tiers: MK I, MK IV, and MK VI.

Behind the scenes[]

  • Nuka-World and Fallout 76 established the armor as an experimental pre-War design used by the Enclave as the basis for the armor developed from 2220 onwards.
  • The designation "X" is used by military R&D as shorthand for "experimental." X-01 translates to "experimental model number 1".
  • The Fight for Freedom Scoreboard shows astronauts using X-01 style space suits, albeit with different helmets.


  1. 1.0 1.1 1.2 1.3 The Whitespring bunker terminal entries; archival terminal, Prototype Power Armor Schematics
  2. Bradberton's officer terminal entries; Bradberton's project terminal, 10-20-2076 JCB
  3. Fallout 4 loading screens: "The X-01 series of Power Armor was specially engineered and employed by remnants of the U.S. military after the Great War, and offers increased protection over the older, pre-war models."
  4. Institute paint
  5. Fallout 2 item description: "{34800}{}{Advanced Power Armor}
    {34801}{}{This powered armor is composed of lightweight metal alloys, reinforced with ceramic castings at key points. The motion-assist servo-motors appear to be high quality models as well.}"
    (PRO ITEM.MSG (Fallout 2))
  6. The Institute skin bears the label "X-01-I P10 POLYMERIZED CASTING MIX C78A18N3G1"


  1. 1.0 1.1 Fallout Bible 0:
    2198 Enclave works on various new technologies, including Power Armor variations. None of these are much of an improvement over the conventional old school Power Armor, and some are actually worse.
    2215 Under Presidential Order, Enclave scientists begin to work on an upgraded version of Power Armor. Many prototypes are developed and tested.
    2220 October Enclave scientists develop a reliable version of the Mark II Power Armor. The prototype results (and accidents... and explosions... and deaths) are classified by order of the President Richardson for the sake of morale."