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Fires multiple Fat-Man shells. At once. That's a lot of fat.— In-game description

The MIRV is a weapon that appears in Fallout Shelter.


This section is transcluded from Fat Man. To change it, please edit the transcluded page.

The M42 Fat Man was developed at Fort Strong near Boston, Massachusetts. Development began in February 2076, with the goal being the development of a man-portable tactical nuclear launcher easy enough for use by troops on the ground, to destroy reinforced and entrenched positions.[1][2] Problems manifested instantly, as warheads were simply too heavy to clear the blast radius fast enough to provide safety for the operator. Even stripping them to the minimal possible size failed to produce an acceptable effect. Instead, the development team decided to increase the power of the launcher unit, even considering using railgun technology to accelerate the warhead. The notion was largely academic, as it would require for the overburdened soldier to carry an additional power pack the size of a suitcase and turn the Fat Man into a crew-served weapon.[3] Concurrent development ran on the MIRV version of the launcher. Live-fire testing claimed lives, in fact, with two soldiers killed during a test. No remains were recovered and the commanding officer in charge of the project, General Brock, covered up the incident, ordering his subordinates to send sand packed in an urn to their relatives.[4]

The project hit a breakthrough in December 2076,[5] when the project lead discovered a solution for the launcher problems. Six hours, fourteen cups, and one concerned night shift lab crew later, the future M42 launcher was conceptualized: Based on the spigot mortar mechanism, the launcher would only have to accommodate a firing through and system, relying on mechanical launching, rather than chemical or electrical means. The Fat Man warhead would be propelled by a sub-charge embedded inside the warhead, "catapulting" the warhead through the air to the target - giving plenty of range with the added bonus of not producing a smoke trail that could reveal the firing team to the enemy.[6]

By September 2077,[7] after one hundred test firings the weapon was complete and ready to be shipped to units overseas. A large number of units was manufactured and shipped together with the appropriate warheads to select locations throughout the United States.[8]


The MIRV is a unique nuclear launcher featured in Fallout Shelter. Dealing 22 - 27 damage per attack (avg 24.5), it has the highest damage output for a heavy weapon in the game.



Weapon name Weapon damage Weapon value Rarity
Rusty Fat Man 22 500 legendary
Fat Man 22-23 500 legendary
Enhanced Fat Man 22-24 500 legendary
Hardened Fat Man 22-25 500 legendary
Guided Fat Man 22-26 500 legendary
MIRV 22-27 500 legendary



A high Strength statistic is needed to effectively create the MIRV.

Shovel (3)
Caps x22,050
MIRV (1)


Contrary to what one might expect from a nuclear catapult, all variants of the Fat Man in Fallout Shelter are poor choices for combat against multiple opponents. Every target in the room is hit at once, but the weapon's listed damage output is split evenly between each target instead of being applied to each one in full. Refer to the weapons page for details.