Sentry Bot (Fallout 4)

A sentry bot is a type of robot found in the Commonwealth in Fallout 4.

Characteristics
The Commonwealth variants of the Sentry Bot are similar in overall appearance to the ones encountered in the Capital Wasteland and Mojave but are even larger (on par in height to a human wearing Power Armor), appear to have a bulkier construction and are substantially more resilient. Weapons of the sentry bot remains the same as seen in Fallout: New Vegas, with a missile launcher and minigun being a typical combat load (except these miniguns appear to be unique 3 barreled variants chambered for the 5.56mm round.) However alternate weaponry configurations such as dual miniguns can be observed as well.

On top of which, Sentry Bots now have powerful melee attacks and a self-destruct function with equivalent power to a mini nuke. Some variants appear to have four legs instead of three as seen in the previous versions. This may be due to the Commonwealth's rocky terrain requiring a greater amount of stability or its sheer bulk requiring a greater strength to make it operable. They seem more durable than previous iterations of the sentry bot in other games.

A similar variant to the Commonwealth sentry bots can be found in Fallout: New Vegas at the REPCONN museum. Newer versions in Fallout 4 appear to use mecanum wheels that allow it to move right and left without having to turn.

Gameplay attributes
Sentry bots are some of the rarest and the most difficult robots to defeat - fast, agile, heavily armed and resilient enough to absorb a direct hit from a Mini nuke. After losing both main weapons they initialize their self-destruct sequence and charge at the player character. Even with their ranged weaponry intact, sentry bots often charge into close combat to deliver powerful blows with their arms if one ventures too close, thus deterring attackers from any use of melee weapons. Since they explode on death with the force of a mini nuke, this tactic may prove even more dangerous to their opponent than their devastating long-range firepower.

Should one encounter a legendary sentry bot of any kind, keep in mind that all legendary robotic enemies explode upon death. This explosion does not override the sentry bot's in-built self-destruct, which means a legendary sentry bot will explode twice. Both explosions are equivalent to a mini nuke in power and occur with a short delay of a few seconds.

Sentry bots are a good source of fusion cores, dropping at least two when they are destroyed, along with other valuable electronic components.

Low level players can defeat a sentry bot by hiding and running away until the sentry bot takes a few seconds to cool off, revealing its vulnerable fusion cores in its back. Firing any shot at them will instantly kill the sentry bot, however, the cool-down lasts only 2-3 seconds so one must act quickly. Even after destroying a sentry bot's fusion cores, it will still drop at least two of them.

Prototype MKIV
An inactive combat sentry prototype MKIV can be found at the Robotics Disposal Ground. Inside the shed near the entrance to the facility there is a terminal that has a holotape loaded. Initiating the holotape on the terminal activates the sentry bot outside, after which it immediately starts to patrol the area.

By ejecting the holotape from the terminal and using it in the player character's Pip-Boy the Sole Survivor can command the sentry bot to different locations in the Commonweatlh to clear of enemies, after which it will return to the junkyard. However, these locations are limited to nearby military sites.

Locations

 * A sentry bot will attack the Sole Survivor after exiting the National Guard Armory.
 * A sentry bot will be seen guarding the outside of Cabot House.
 * Northwest of Murkwater construction site and South of Suffolk County charter school is what appears to be a partially submerged power station. If the player opens a door in the center building they will see a cinder block wall with a graffiti message that reads "YOU LOOK NICE TODAY!" and a sentry bot will spawn on the opposite side of the building and start attacking the player.
 * There's a sentry bot in a cage West of Somerville Place (it'll attack if you pick the lock on the door or you attack it first).
 * A hostile sentry bot can be found guarding a shack West of Medford Memorial hospital
 * A sentry bot in the tunnels under The Castle named Sarge will attack on sight.
 * Like every other Legendary version of any robotic enemy, a killed Legendary Sentry Bot will always explode in an explosion comparable to a mini nuke when defeated, regardless of how damaged it was.

Notable sentry bots

 * Captain Ironsides - non-hostile protector of the USS Constitution in Last Voyage of the U.S.S. Constitution.
 * Sarge - encountered inside the armory of The Castle in the quest Old Guns.
 * Gus - in a special encounter, non-hostile sentry bot that roams with Kat, child trader.

Bugs

 * At Robotics Disposal Ground, the prototype sentry bot MKIV does not move once powered on.
 * Fast traveling elsewhere and sleeping can fix the problem. This is confirmed to work.
 * Using the Robotics Expert perk to disable and then re-activate the sentry bot can also fix the problem.
 * Using the console to 'disable' and 'enable' the sentry bot should fix the problem, too. Simply enter the console and click on the sentry bot, then write 'disable' after that use the 'enable' command and exit the console.
 * The bot will occasionally disappear when it is in patrol mode.

Gallery
Робот-охранник (Fallout 4)