Gameplay articles
FalloutStealth Boy
Fallout 3Stealth Boy
Fallout: New VegasStealth Boy
Stealth Boy mark II prototype
Fallout 4Stealth Boy
Railroad Stealth Boy
Fallout 76Stealth Boy
Stealth Boy Mark III
Phantom Device
Fallout TacticsStealth Boy
Fallout: New CaliforniaStealth Boy
Fallout: BoS 2Stealth Girl
This is an overview article, focusing on background information and cross-game comparisons.

The RobCo Industries Stealth Boy 3001 is a personal stealth device.


One of the most interesting technologies developed before the war, the Stealth Boy 3001 is a wrist-mounted device that generates a modulating field that transmits the reflected light from one side of an object to another (called stealth radiation[1]). The end result is practical invisibility, which can range from translucency to near-perfect active camouflage.[2][3]

The underlying technology was never fully understood by American scientists, with American produced stealth technologies reliant on reverse engineering Chinese Hei Gui stealth armor[4], but these proved reliable enough for military purposes. In fact, it was enough to convince the military to have had these devices mass produced by RobCo.[5][6] Even more, work started on a more advanced Stealth Boy mark II prototype.[7] After the Great War, developed by Enclave scientists in Appalachia, the Stealth Boy Mark III was an overall improvement of the Stealth Boy, coming at the cost of reverting back to a specialized canvas holder design rather than a wrist-mounted design.

There are drawbacks to the Stealth Boy, however. Apart from limited battery life, particularly when used at full power to achieve total invisibility, the modulating field can cause permanent neurochemical changes,[8] resulting in the development of mental conditions, such as paranoia, delusions, hallucinations, and even schizophrenia.[9] This is by far most noticeable among the nightkin, former elite members of the Unity and their prolonged Stealth Boy use and apparent increased susceptibility of super mutant physiology to stealth radiation. Nightkin tend to suffer from delusions, anxiety attacks (particularly when deprived of their Stealth Boys), and heightened aggression (particularly when trying to acquire Stealth Boys to cope with their withdrawal symptoms). Treatment is difficult and usually focuses on symptoms, due to the inability to address the underlying cause (yet).[10][11][Non-game 1]


Stealth Boy Mark I

Fallout4 Stealth Boy.png
Stealth Boy.png

The Stealth Boy 3001 is the most common variant of active camouflage devices in the wastelands, manufactured in a variety of portable forms, including a wrist-mounted disc and an emitter in a canvas carrying pouch worn on the belt. Stealth Boys offer a number of power settings allowing anything from total invisibility to partial translucency. Tanya MacMillen speculated that the device was powered by small energy cells.[12]

Stealth Boy Mark II prototype

Gameplay article: Fallout: New Vegas

The Stealth Boy Mark II prototype is an enhanced Stealth Boy, put through testing by the U.S. military shortly before the Great War. According to Doctor Henry, its purpose was to use less power and therefore last longer.[13]

Stealth Boy Mark III

Stealth Boy Mark III.png
Gameplay article: Fallout 76

Developed by Enclave scientists in Appalachia with the help of Chinese schematics and MODUS,[14] the Stealth Boy Mark III was the total improvement of the Stealth Boy. While no longer wrist mounted (instead reverted back to a canvas box), the power consumption rate was drastically lowered from the Mark II Stealth Boys allowing for longer invisibility time until power was drained.

Phantom Device

Phantom device.png
Gameplay article: Fallout 76

A satchel model Stealth Boy modified by the Order of Mysteries with a cloud of HalluciGen gas that cloaks the user, frenzying nearby enemies.

Railroad Stealth Boy

Gameplay article: Fallout 4

The secretive organization The Railroad gained access to a more powerful variant of the normal Stealth Boy. Their resident engineer Tinker Tom sells the devices to trusted agents.

Behind the scenes

  • Although it is mentioned in Fallout 2 and its description is present in Fallout Tactics files, the item was absent from the games themselves. The device's backstory wasn't developed until Van Buren, the canceled Fallout 3 by Black Isle Studios, where it played a role in the backstory for the Maxson Bunker and its denizens: The Brotherhood of Steel experimented with those devices to gain an edge in the war against the New California Republic. However, when the deleterious side effects on the user's psyche were discovered, the devices were banned and the team disbanded. However, it was not known that the team had already begun to suffer the effects of the device, in the form of paranoid delusions. Thinking the disbanding of their team to be a conspiracy against them, the operators stole their Stealth Boys and formed their own order, the Circle of Steel.
  • Additionally, Van Buren spelled the device as StealthBoy to prevent it from being confused with the "Stealth Boy" playing style. Subsequent games incorporated much of the backstory into the mainstream canon.[citation needed]



  1. The Courier: "I found a chewed up Stealth Boy in the Nightstalker lair."
    Henry: "Hmmm... there's still power, but the casing is cracked. I'm astonished that exposure to the stealth radiation could induce mutations so rapidly. More importantly, this explains why my research into this group of Nightstalkers hasn't come up with a cure for the Nightkin. There's only one avenue left for me - I need to run the Mark II test on Lily. It's the only way."
    (Henry's dialogue)
  2. Fallout item description: "{5400}{}{Stealth Boy}"
    "{5401}{}{A RobCo Stealth Boy 3001 personal stealth device. Generates a modulating field that transmits the reflected light from one side of an object to the other.}"
  3. Museum of Technology placard: "This is the RobCo "Stealth Boy" Model 3001 Personal Stealth Device. Developed by Robert Mayflower, the Stealth Boy generates a modulating field that transmits the reflected light from one side of an object to the other making the bearer almost invisible to the untrained eye."
  4. The Switchboard terminal entries; research terminal, > 2075 Dec 17
  5. Availability of Stealth Boys in Fallout 3 and New Vegas
  6. REPCONN test site terminal entries; Re: Shipment Mistake?
  7. The Courier: "What are you working on?"
    Henry: "The Nightkin have varying degrees of mental instability due their addiction to Stealth Boy use. I've been trying to come up with a cure. I'm currently investigating the local Nightstalker population since they seem to have developed a natural stealth field. I've also gotten my hands on a working Stealth Boy Mark II prototype, but that experiment is riskier. I'd rather not pursue that research just yet."
    (Henry's dialogue
  8. The Courier: "What makes you think that the Nightstalker mutation isn't natural?"
    Henry: "I've compared the brain chemistry of a Nightkin to one of the local Nightstalkers we killed. They both exhibit similar neurochemical changes. Now, I'm not claiming that Nightstalkers are running around wearing Stealth Boys, mind you. I just don't think it's all a coincidence."
    (Henry's dialogue)
  9. The Courier: "What's wrong with the Nightkin?"
    Marcus: "Nightkin suffer schizophrenia from the Stealth Boys they're always using. One of the reasons I settled Jacobstown was so they could be cured. While they're in town, the Nightkin aren't allowed to have Stealth Boys so their craziness doesn't get worse. Trouble is the Nightkin don't like being visible, either. They don't take being exposed too well."
    (Marcus' dialogue)
  10. Jacobstown
  11. The Courier: "Why does Keene want to leave?"
    Marcus: "Because of a promise. One I haven't been able to keep. The Nightkin all suffer from schizophrenia. It's the Stealth Boys they use, used to use. Nightkin have a hard time being seen like normal folks. Can't stand it. A few already left to try and find more Stealth Boys. Miserable situation. They either stay here and suffer, or dig up Stealth Boys and lose their minds. Not much of a choice."
    (Marcus' dialogue)
  12. One Woman's Path Through the Desert#Day 187
  13. The Courier: "Why is the Stealth Boy Mark II riskier?"
    Henry: "The stealth field has been modulated to use less power and thus last longer, but for some reason it has pronounced negative effects on the user. However, these pronounced effects will allow me to pinpoint exactly what parts of the brain they're affecting. Unfortunately, I'll need to run the test on a live subject, and Marcus has encouraged me to investigate the Nightstalker mutation first."
  14. The Whitespring bunker terminals#RE: Chinese Stealth Tech
  1. Fallout 2d20 Rulebook p.171: "One of the most interesting technologies developed before the War, the Stealth Boy 3001 is a compact device which generates a modulating refraction field which transmits light from one side of the field to the other. The result is near-perfect active camouflage, ranging from a sort of distorted transparency when moving to almost total invisibility when stationary.

    The Stealth Boy was reverse engineered from captured Chinese Stealth Armor during the War, and while the technology was never perfected—even the most advanced Stealth Boy consumes its battery in around 30 seconds—it was still seen to be reliable enough for service. Long-term use of Stealth Boy technology has been observed to cause permanent neurological changes, resulting in paranoid delusions, hallucinations, and other mental changes."
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