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This is a lore summary, presenting intradiegetic or in-universe information about the subject. For game characteristics and similar data, consult the table on the right.
Game-specific articles
Fallout 3Mini nuke
FO: New VegasMini nuke
Gun Runners' ArsenalMini nuke, big kid
Mini nuke, low yield
Mini nuke, timed
Mini nuke, tiny tots
Fallout 4Mini nuke
Fallout 4: NWNuka-Nuke
Fallout 76Mini nuke
Fallout: BoSMini nuke grenade
Gametitle-FO3.pngGametitle-FNV.pngGametitle-FNV GRA.pngGametitle-FO4.pngGametitle-fo4nw.pngGametitle-F76.png
Gametitle-FO3.pngGametitle-FNV.pngGametitle-FNV GRA.pngGametitle-FO4.pngGametitle-fo4nw.pngGametitle-F76.pngGametitle-FOBOS.png

The mini nuke is an ammunition type found in Fallout 3, Fallout: New Vegas, Fallout 4, and Fallout 76.


A standard micro-nuclear bomb used by the M42 Fat Man. From the top, it consists of a beryllium cap, hemisphere core (here shown without the detonator), detonator shell, and stabilizer fins.

Developed at Fort Strong as part of the M42 Fat Man project, the mini nuke is one of the most powerful conventional weapons ever devised. Though the project was plagued by design issues from the beginning, caused by the weight of the micro-nuclear warhead and the resulting low range, the designers eventually happened upon a break through: Instead of trying to reduce the weight of the warhead or the power of the launching system, one researcher proposed falling back on the spigot mortar system, used over 130 years before in PIAT launchers. The ingenious solution was just what was needed to complete the project and by September 2077 the first M42 Fat Man weapon systems were sent to ordnance depots across the United States.[1][2][3]

The mininuke consists of four principal components. The detonator shell on the bottom contains a conventional sub-charge that detonates when struck by the M42's striking pin, catapulting it out of the launcher. Four stabilizer fins attached to it ensure a stable trajectory and prevent tumbling in flight, increasing accuracy (a necessary feature, as the projectile is not spin-stabilized). The hemisphere core is screwed onto the top, containing the nuclear core. Finally, the weapon is fitted with a beryllium contact fuse that starts the nuclear reaction on impact.[4][5][6]


Mini nuke

Mini nuke.png

The baseline variant, providing a balance between firepower and range.


Gameplay article:

Stronger than mini nukes, but are exceedingly rare.

Mini nuke, Big Kid

Mini nuke.png
Gameplay article:

Similar to a regular mini nuke in affect but produces a larger explosion with an increased ballistic range and fallout radiation area.

Mini nuke, low yield

Mini nuke.png
Gameplay article:

Similar to a regular mini nuke in affect but produces a much smaller explosion with a shorter ballistic range.

Mini nuke, timed

Mini nuke.png
Gameplay article:

Once fired, this type of mini nuke will detonate after 5 seconds rather than upon contact.

Mini nuke, tiny tots

Tiny Tots.png
Gameplay article:

Loaded and fired like a standard mini nuke, but breaks upon launch into 9 smaller "tots" with each producing their own equally tinier explosion. Good for carpeting a wide area without the waste of several mini nukes.


Fat mine

Fat mine.png
Gameplay article:

An improvised explosive device, created by bypassing the beryllium cap with a three-second delayed proximity fuze. Though crude, it is an incredibly effective explosive device.

Mini-nuke grenade

FOBoSLogo.pngThe following is based on Fallout: Brotherhood of Steel and has not been confirmed by canon sources.

As its name would imply, the mini-nuke grenade is all the power of a mini nuke, packed into a hand-held explosive device.



  1. Fort Strong terminals; Bravo Team Testing Terminal, Bravo Team M42 Report 001: "Things are getting tough around here. Brock has decided to split our men into two teams. I drew one of the short straws, so I ended up on the M42 "Fat Man" Launcher team while most of my buddies are sitting pretty upstairs with the T-51B suits. I can't even begin to describe what a ridiculous idea the M42 is - a man-portable mini-nuke thrower that a trooper in the field is supposed to deploy at close range. I've been pouring over the schematics and I have no idea how were going to get this thing to throw a warhead far enough not to kill the soldier unlucky enough to be stuck with these deathtraps."
  2. Fort Strong terminals; Bravo Team Testing Terminal, Bravo Team M42 Report 002: "We've stripped the warhead weight down as much as possible, but I think we're looking at this the wrong way. Instead of trying to reduce the warhead weight, we should try and amp the power on the thrower itself. I know that means adding weight to an already heavy piece of ordinance, but I don't think we have any choice. One of the guys suggested we try magnetics to push the warhead through like a rail gun, but the power pack would need to be the size of a suitcase. I'll keep picking away at this problem and see what I can turn up."
  3. Fort Strong terminals; Bravo Team Testing Terminal, Bravo Team M42 Report 003: "We lost two good soldiers this morning. They were on the surface testing a MIRV variant of the launcher, when one of the warheads misfired and hit the ground right where they were standing. Poor bastards didn't even have a chance. We couldn't even find any remains to send home to their folks, so Brock told us to just fill some cans with sand. I'll tell you, that guy doesn't give a crap about us, he's just worried about the brass back in Washington giving him a hard time."
  4. Fort Strong terminals; Bravo Team Testing Terminal, Bravo Team M42 Report 004: "I was in bed last night when I had one of those "Eureka" moments. I ran over to the night shift guys in the lab, swept all of their drawings on the floor and starting sketching my idea. They must have thought I'd lost my mind. Six hours and about fourteen cups of coffee later, and I had it all mapped out. We'd use a small sub-charge as a launching catalyst to catapult the warhead from the launcher. We'd have plenty of range, and the sub-charge could be built into the warhead itself. Brock seemed to like the plan and gave us the go ahead to prototype the device. I can't wait to try it out."
  5. Fort Strong terminals; Bravo Team Testing Terminal, Bravo Team M42 Report 005: "It took the better part of a year, and over a hundred test firings, but the M42 is ready to shipped out into the field. I can't believe I spent over a year on this single project. I feel pretty good knowing we're delivering a well-tested weapon to our own guys fighting overseas. Now that it's over, I suppose Brock will move us on to something else, but for now I'm going to spend the rest of the month packing up these warheads to ship off base."
  6. Fort Strong terminals; General Brock's Terminal, General Brock's Report - December 2076: "Bravo Team is having a heck of a time getting the M42's not to shoot far enough away from its firing position. The problem is that the warhead is still too heavy to fire the distance required - our simulated soldiers are still soaking far too many rads and suffering blast burns. One of the technicians has suggested a radical idea of using a conventional depleting sub-charge to catapult the round rapidly out of the launcher. His calculations look sound, so I am going to let him give it a try."