| ||For an overview of Stealth Boy devices in all games, see Stealth Boy.|
The RobCo Stealth Boy 3001 is a personal stealth device worn on one's wrist. It generates a modulating field that transmits the reflected light from one side of an object to the other, making a person much harder to notice (but not completely invisible).
While they seem to not have any adverse effects on humans, Stealth Boys increase the risk of schizophrenia in nightkin, who, as permanent Stealth Boy users, nearly always show one or several symptoms of paranoid schizophrenia, such as paranoia, hallucinations, and/or delusion. Doctor Henry in Jacobstown is researching these side effects, hoping to develop a means to help the nightkin.
- One can be found in the Goodsprings schoolhouse, in a locked safe (Lockpick 25).
- Another is carried by Joe Cobb.
- Several can be found at the REPCONN test site.
- One can be found next to the dead nightkin near the front door.
- Two can be found inside a safe in one of the second floor rooms. (Both take a Lockpick skill of 25 to unlock)
- Two can be found on the third floor inside a safe behind a half circle desk (requires a lockpick skill of 50).
- They can be randomly found on each nightkin the player kills in the basement during the quest Come Fly With Me.
- Another can be found in the basement, on one of the tables in the room with the sign reading "Food".
- Atticus in the Caesar's Legion safehouse can give two to the player for free, each time they encounter him there during their visits.
- The repeatable side-quest Caesar's Favor can provide a random supply of Stealth Boys each time, sometimes in very large quantities.
- One can be found in the middle of Jack Rabbit Springs, beside a skeleton found lying near an upright post visible on the hillside.
- Approaching the cattle pen at Brooks Tumbleweed Ranch reveals a nightkin who offers to sell you a 'wind brahmin' (a tumbleweed) for all your caps. Originally, he will then give you a Stealth Boy as a gift; killing the nightkin afterwards (or pickpocketing him) produces another Stealth Boy, as well as all your caps back. But with the game patch released July 7–8, 2011, he will no longer give you a Stealth Boy and will take all of your caps instead, and you can only get one Stealth Boy from the nightkin by either killing or pickpocketing him.
- Old World Blues (add-on) Passing the "Robot Compliance Test" to upgrade the stealth suit Mk II at the X-13 research facility may yield a Stealth Boy in the reward safe. This test and three others can be repeated and give random rewards each time, including Stealth Boys.
- Old World Blues (add-on) In the nightstalker test area of the facility, shooting the forcefield in the ceiling of the small room with the Strange Still with an upgraded sonic emitter will drop a Stealth Boy into the room.
- Old World Blues (add-on) In the Y-17 medical facility located near the Auto-Doc in the center of the room, it will be on the floor close to the rubble surrounding the Auto-Doc.
- With Fallout: New Vegas patch 18.104.22.1684, Stealth Boys may randomly spawn in ammunition boxes.
- Many may be found in the footlockers at Camp Golf.
- 3 may be found at the Hidden cazador nest near Brewer's beer bootlegging.
- One will be given by Lily in Jacobstown when adding her as a companion in the quest Guess Who I Saw Today.
- On very rare occasions, some merchants may sell a Stealth Boy.
- One can possibly be found in the hollowed-out rock next to the drainage gate to the Brotherhood of Steel bunker.
- Vault 11 lower level, some can be found in ammo boxes.
- Although plentiful in Fallout 3, they are less common in Fallout: New Vegas, with Caesar's Legion and the X-13 research facility being the only long-term supply option for the devices.
- The duration of the effect is 2 minutes, about one game hour.
- Having Lily as a companion doubles the duration of the effect, for a time of up to 4 minutes.
- The Chemist and Day Tripper perks also affect the Stealth Boy duration. Having all 3 affecting perks significantly increases Stealth Boy duration - up to 10 minutes, 38 seconds.
- Stealth Boys temporarily increase your Sneak level to 100, which affects stealth-related Speech checks.
- Although it is considered a technological device, pulse grenades do not have any effect on the Stealth Boys.
- There may be a bubble-like texture above your Pip-Boy when using the Stealth Boy, which disappears when your Pip-Boy light turns on.
- The effect lasts for one in-game hour, or 2 real-time minutes. If you use an additional Stealth Boy when a previous one is still active, the duration of the stealth effect does not replenish - it "stacks", so the effect will last two in-game hours.