The first Mister Handy was introduced to the robotics market in 2037 by General Atomics International, as a general-purpose construction and maintenance unit. Used widely on both the American and Mexican markets (especially after the Mexico City earthquake of 2042), it was a rugged, reliable design. So reliable that it only received one major hardware update in 2039, to eliminate a bug causing interference in the operation of the multiple arms. The Calpower 238B nuclear power unit and self-maintenance modes were key to its success, ensuring each robot's longevity. To minimize maintenance overhead, each Mr. Handy was designed to perform its nuclear fuel replacement and radiation cleansing. Each unit could carry out maintenance and repairs on other units (it could not carry it out on itself).
However, as rugged and reliable as the original Mr. Handy was, it was still a design rooted in the technology of the 2030s, with a compact computer brain that was incapable of learning or executing complex tasks without extensive programming. By the 2070s, it was an automaton surrounded by more advanced designs utilizing cutting edge neural networks. In order to maintain their market share, General Atomics entered into a joint venture with RobCo Industries, combining its talent with General Atomics' experience in robotics. The resulting model was a sleek, elegant design capable of self-programming and initiative, more than making up for halving the number of arms to just three. Despite its sophistication, it was also cost-effective, making it the perfect domestic servant robot. The success of this model resulted in the development of several additional models, including dedicated medical and military versions. Sometime before the Great War, General Atomics International and RobCo wanted to upgrade their Mister Handy line by adding an additional hand alongside additional features.
Mister Handy robots are service and maintenance robots with spherical chassis, with three optical sensors fitted on top. They can move around using a jet-powered propulsion system, which enables them to hover a few feet above the ground. They have three primary appendages for manual labor, two of which are fitted with a buzz saw and a rudimentary flame thrower. Each unit is equipped with an artificial intelligence system, acting as an interface and operating system. A series of limiters placed on its pathways prevents the units from developing their independent consciousness, and from performing actions that are not part of its programming.
Despite not originally being designed for combat, the Mister Handy robots are robust, due to their intended purpose of executing maintenance tasks in potentially hazardous environments. They can pose a threat to lower level player characters, as their buzz saw and flamethrower can prove deadly in close quarters.
Relatively uncommon, with a few notable named versions such as Andy, Godfrey and Wadsworth. Before the Great War, they served mainly as a household helper and 200 years later they still serve that role.
The McClellan Mister Handy can be found in the townhome of the McClellan family in Georgetown. Before the Great War, this particular Mister Handy unit served as the personal assistant for the McClellan family, and will still perform various day-to-day chores for them, such as walking the dog and going grocery shopping if the player character chooses to activate him via a nearby terminal.
Mabel Henderson's Mister Handy is part of the Tranquility Lane virtual reality simulation in 2277. It's a household maintenance robot who cooks, cleans and irons so that Mabel doesn't have to. In Tranquility Lane its safety mode can be disabled, leading it to kill Mabel. It will also attack the Lone Wanderer unless it is destroyed or the safety mode is reactivated using the nearby terminal. It is the only Mister Handy in Tranquility Lane.
The following is based on Fallout 3 cut content and has not been confirmed by canon sources.
Mister Mulberry is a cut Mister Handy which was set to appear in Megaton. He is a non-hostile character, but he only has two generic dialog lines. Mister Mulberry can be found in Fallout 3's game files, with his reference id being 1d770.
The McClellan Mister Handy is important and unique in that it can be controlled by a terminal in the house. Upon using the terminal, there will be five options, each allowing some form of activity with the McClellan Mister Handy:
"Deactivate Unit" - recalls the Mister Handy to its base.
"Walk Muffy"- instructs the Mister Handy to walk the McClellan's dog, Muffy. Mister Handy will travel outside, find the dog's body, and then attack you. It will refer to you as the dog when it does this, apparently as a means of reconciling its shattered reality.
"Pick up Grocery Order" - directs the Mister Handy to the nearby grocery shop. However, it will just stop at the door and come back home (if it isn't destroyed en route by super mutants or other enemies).
"Read Children Bedtime Poem" - instructs the Mister Handy to go to the children's room and begin reciting a poem. Curiously, despite its rather violent reaction to the dog being dead, it does not seem to care that the children are deceased; after telling the bedtime poem, he continuously repeats "Of course, of course. Don't let me keep you," until you decide to recall him.
"Home Security Mode" - sets the unit to patrol mode, searching out any enemies.
↑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!" (Tour guide's dialogue)
↑Fallout 4 loading screens: "Created by General Atomics International as a domestic servant robot, Mister Handy is equipped with tools that can be used as weapons, if the need arises."
↑Fallout 76 loading screens: "The pride of General Atomics International, the Mister Handy was designed as the ultimate domestic servant. If needed, however, his various attachments can be used for defense."
↑Variants in Fallout 3, Fallout: New Vegas, and Fallout 4.