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Fallout Wiki
Gameplay articles
Fallout 2Sentry bot
Fallout 3Sentry bot
Enclave sentry bot
U.S. Army sentry bot
Outcast sentry bot
Strike team sentry bot Operation: Anchorage (add-on)
Presidential metro sentinal unitBroken Steel
Fallout: New VegasSentry bot
Hardened sentry bot
Prototype sentry bot
Sentry bot mark series Old World Blues (add-on)
RY-589 Ultimo bot Old World Blues (add-on)
Cut content NCR sentry bot
Fallout 4Sentry bot
Siege breaker sentry bot
Gunner sentry bot
Gunner siege breaker sentry bot
Annihilator sentry bot
Gunner annihilator sentry bot
Annihilator sentry bot Mk II
Gunner annihilator sentry bot Mk II
Combat sentry prototype MkIV
Sentry bot ripper Automatron (add-on)
Sentry bot lament Automatron (add-on)
Sentry bot carnage Automatron (add-on)
Sentry bot butcher Automatron (add-on)
Sentry bot reaper Automatron (add-on)
Space sentry Nuka-World (add-on)
Space sentry breaker Nuka-World (add-on)
Space sentry annihilator Nuka-World (add-on)
Space sentry obliterator Nuka-World (add-on)
Fallout 76Sentry bot
Sentry bot siegebreaker
Annihilator sentry bot
Annihilator sentry bot Mk. II
Whitespring sentry bot
Enclave sentry bot
Hornwright security robot
Sentry bot strikebreaker
Arktos Pharma sentry bot Wild Appalachia
Whitespring elite security force Nuclear Winter
This is an overview article, listing content appearing across multiple games.
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Sentry bot is a robot that appears in Fallout 2, Fallout 3, Fallout: New Vegas, Fallout 4 and Fallout 76.


The heaviest class of combat robot in the United States Armed Forces, the sentry bot's singular purpose is to provide security through overwhelming firepower.[1] The sentry bot had become a standard piece of military equipment by at least 2063, with prototypes existing further back.[2] The sentry bot's purpose is to engage the enemy at range with a variety of weapons, including miniguns, Gatling lasers, rocket launchers, and even back-mounted cluster grenade launchers. At the same time, its thick armor and multiple redundant systems allow it to survive extended engagements. It is commonly considered to be one of the most dangerous robots ever created and RobCo Industries' finest fighting robot. Late models are also provided with the ability to self-destruct to prevent the enemy from recovering the robot.[3] Early sentry bot models were issued serial numbers in the SB-#### format (model, then serial), with later models transitioning to the standardized alphanumeric registration in the ABC-###### format.[4]


Gameplay article: Fallout: New Vegas

An antique prototype of RobCo's sentry bot line that didn't enter mass production. This prototype model features four legs on articulated mounts, with two sets of three jets mounted where the arms would be present in the production model. Hardpoints are present on the arms, which are attached on the back and flank the head assembly. The weapons themselves are a pair of 5mm miniguns in a Gatling laser mount.[5]

Production models

Bipedal model

Gameplay article: Fallout 2

An early sentry bot model also referred to as a security robot. Walking on two legs and clad in heavy armor, it carries a pair of weapons: A minigun on the left and a specially-designed multiple missile launcher on its right arm. Vision is provided by the head unit, with a single, central red eye. This old design has been largely retired by the Great War, as its height - well over two meters - and instability resulting from its center of gravity and two legs limited its performance in the field. It's a rare sight in the wasteland, with the only known facilities to use this elderly model being the Sierra Army Depot and the Enclave Oil Rig.

RobCo Industries early model

Sentry bot.png
Gameplay articles: Fallout 3, Fallout: New Vegas

An early sentry bot model developed by RobCo Industries, designed specifically for heavy combat. The bot is divided into two halves. The upper body contains the central processing unit, power core, and mounts the primary optical receptor. The bot is protected by a cast armored shell, consisting of just three pieces: The torso and upper assembly, a separate rear plate giving access to internal mechanics, and the head assembly protecting the main optical receptor. Its arms act as hardpoints, accepting a variety of weapons including miniguns, Gatling lasers, and rocket launchers. The lower body is connected by four shock absorbers and a centrally-mounted duct. It contains fans venting accumulated hot air outside the chassis, preventing overheating. For movement, the lower body is fitted with three independent legs that provide it with a stable firing platform in any environment, much like a machine gun mount. The legs terminate in semi-spherical wheels (rubberized on the front and solid steel scoops on the back), giving it excellent mobility as well.[6][7] Unlike the Gutsy or Assaultron, all sentry bots come with a simple synthetic personality.[8]

RobCo Industries late model

Gameplay articles: Fallout 4, Fallout 76

The ultimate in high-end robotic engineering,[9] the next-generation sentry bot is the heaviest and most powerful pre-War military robot design that reached operational status. It contains two distinct assemblies. The upper body, protected by a rounded, cast armored shell, contains the primary systems of the sentry bot together with the fusion core sockets. A pair of large fans help cool down the torso assembly, while hinged flaps over the fusion cores allow for emergency venting if heat buildup reaches critical levels (its only major vulnerability).[10] The head is mounted at the front, on an articulated mount that offers a degree of mobility, and typically protected by an additional level of armor. The arms act as hardpoints, accepting a variety of loadouts including a tri-barrel minigun and a triple-shot missile launcher. An additional hardpoint is installed on the back of the sentry bot, allowing for a pair of cluster grenade launchers.[11]

The lower body retains the original's wheeled chassis, with three legs terminating in wheels providing a stable firing platform in almost any terrain. Hydraulic actuators allow the sentry bot precise control over its position and placement, a major improvement from the previous models. The greatest mobility improvement in this model is the introduction of Mecanum wheels. These allow it to move in any direction in combat, without having to break the line of sight to relocate.[12]

Enclave sentry bot

Fo3BS Enclave sentry bot.png
Gameplay article: Fallout 3

Slightly darker in appearance when compared to the normal variant, the Enclave model boasts improved systems. They appear at Raven Rock and alongside Enclave squads in the wasteland. During Broken Steel they are encountered guarding Adams Air Force Base.

U.S. Army sentry bot

Military sentry bot.png
Gameplay article: Fallout 3

Military robots from before the Great War painted in the characteristic olive green of the U.S. Army. They can be encountered at Fort Constantine, the National Guard depot and when wandering around the wasteland.

Strike team sentry bot

Fo3OA Winterized sentry bot.png
Gameplay article: Operation: Anchorage

The most expensive option for recruitment in Operation Anchorage is a winterized sentry bot, with a built-in minigun and missile launcher, costing 4 recruitment markers.

Presidential metro sentinal unit

Sentry bot.png
Gameplay article: Broken Steel

This unique sentry bot is encountered in Broken Steel, at the end of the Presidential metro, near the metro to Adams Air Force Base. It holds the main fuse, which is needed to repair the nearby powerbox for the metro.

Hardened sentry bot

Sentry bot.png
Gameplay article: Fallout: New Vegas

A hardened sentry bot is a hardened version of the military sentry bot. They are Enclave affiliated, encountered along with hardened Mister Gutsies around the crashed vertibird in the Mojave Wasteland.

Mark series

Sentry bot.png
Gameplay article: Old World Blues

The sentry bot mark series appears only in the Fallout: New Vegas add-on Old World Blues.

NCR sentry bot

Icon cut content.pngThe following is based on Fallout: New Vegas cut content.
Military sentry bot.png
Gameplay article: Fallout: New Vegas

It is similar to the military sentry bot in appearance but is differently colored, with orange eyes instead of the standard red. The NCR sentry bot was originally intended to be stationed in Camp McCarran, evident in its G.E.C.K. id McCarranFieldSentryBot, but was cut from the final version of Fallout: New Vegas.

Icon cut content.pngEnd of information based on Fallout: New Vegas cut content

Siege breaker sentry bot

Gameplay article: Fallout 4

A siege breaker sentry bot is a slightly upgraded version of the normal sentry bot, only appearing in Fallout 4. They can be dangerous opponents for lower level players.

Notable sentry bots



  1. Fallout 76 loading screens: "The Sentry Bot was designed for one purpose: security through overwhelming firepower. Its only real weakness is the short "cool down" phase after attacking, when its fusion core is most vulnerable."
  2. The Wastelad video game was first published in 2063 and features Military Sentry Bots as enemies.
  3. Fallout 4 loading screens: "The Sentry Bot is one of the most dangerous combat drones ever created, and utilizes a variety of heavy weapons systems to destroy its enemies. Upon death, it erupts in a devastating explosion."
  4. Serial numbers in Fallout 3 and Fallout: New Vegas.
  5. GECK ID SentryAntique
  6. REPCONN headquarters placard: ""Watch Your Step!""
    "Whoa, watch your step! You don't want to be facing this fearsome fellow if you accidentally stumble into a restricted area. Whether sporting the latest in dual miniguns, rockets, or laser cannons, the Sentrybot not only takes its job seriously, it also takes no prisoners! It's proof of RobCo's commitment to defense that these deadly guards are concealed in chambers throughout this facility, so let this be a warning: Watch where you step, or out'll come RobCo, guns blazing!"

    "Exhibit Brought to You By Your Friends at RobCo."
    (Fallout: New Vegas message box transcriptions)
  7. Tour guide: "Now for the highlight of our tour! Due to a generous donation from RobCo, this next exhibit showcases the wondrous world of - robots! Around you are the incredible Eyebot, the fearsome Sentry Bot, and the always-helpful Mr. Handy. That helpfulness runs through our whole line! This is the final stop on our tour. This model of our solar system is a small example of where the partnership between RobCo and REPCONN hopes to go. See those little rockets zipping about? They are manned by robots, tirelessly looking for resources to mine on planets beyond our own. And that's it for our tour today, Rocketeers - RobCo and its tiny partner REPCONN thank you! Any further questions, please, feel free to ask."
    (Tour guide's dialogue)
  8. Artificial personality in Fallout 3 and Fallout: New Vegas.
  9. Battlezone Announcer: "And now... the fight you've all been waiting for. The ultimate in high-end robotic engineering. The one... The only... RobCo Space Sentry!"
  10. Fallout 4 loading screens: "Because of its size, the Sentry Bot generates a significant amount of heat. During combat, it will occasionally enter a "cooldown" state. When this happens, the Sentry Bot's back panel will open, exposing its Fusion Core... and presenting the best moment to strike."
  11. Sentry bot appearance and loadouts in Fallout 4.
  12. Sentry bot appearance and behavior.