In Fallout 3, and New Vegas, a weapon can be found called the Fat Man, a Tactical Nuke Launcher.

When you fire it, it throws a mini nuke ahead of you at the enemy. When you reload you hear a "ding" sound to indicate it has finished reloading.

The bell heard is actually the Bethesda lunch room bell.

Inside the basement of the Capitol Post building located in L'Enfant Plaza, there is a corpse named "Gibson". Gibson's inventory has four items, two of which are "Gibson's Key" and "Gibson's Scrap of Paper". The scrap of paper has the following message, "Search the house!"

This references an early scene in Snatcher where the player finds Jean Jack Gibson's corpse and discovers a key and a scrap of paper with the "Search the house!" message among his belongings.

A small, playable text adventure called 'Reign of Grelock' can be accessed from a terminal in Hubris Comics.

"The Plunger Room of Death" is a small area unmarked on the Pip-Boy world map. It is located South of the Chryslus Building, and East of Farragut West Metro Station. The entrance is a door underneath an intact bridge. Inside are dozens of toilet plungers and bloody hand prints on the walls.

In the corner of the map, you can find a building called the Dunwich Building. This building is named after the H. P. Lovecraft story, The Dunwich Horror. The building also takes inspiration from other Lovecraft stories like the Cthulhu mythos.

Near the NN-03d SatCom array, a door can be found built into a rock; Upon opening it there is a wall with "Fuck You" written in green paint.

In Vault 87 is a Super Mutant that calls himself "Fawkes" locked in Isolation Room 05.

This is a reference to the comic-book V for Vendetta, where the main character (V) is originally a prisoner from "Room 5" at Larkhill Internment Camp. After escaping, V dons the infamous mask of Guy Fawkes, the real life British revolutionary known for the failed Gunpowder Plot in 1605.

Both V and Fawkes gain super strength and intellect after their experimentation, which is rare as most Super Mutants only gained super strength but suffered mental drawbacks (or even died), and in the case of V, most subjects did not survive the experiments.

Sneaking up behind and activating a Brahmin will cause your character to push it over.

Liberty Prime is loosely modeled after Gort, from the 1951 movie "The Day the Earth Stood Still."

The "Prime" in Liberty Prime is actually NOT an intentional reference to Optimus Prime from the Transformers, as many people suspected.

The Brahmin in all the Fallout games is in reference to "Brahmin" in Hindu culture, and the name likely plays on Hindu culture's reverence for cows.

However, this (and the fact that you and other NPCs can kill and eat the mutated cows) was viewed as disrespectful, which led to Fallout 3 being banned in India.

The "Experimental MIRV" (a unique Fatman) costs more to fire once than it costs to repair a regular Fat Man twice. At several hundred caps per nuke and firing eight nukes per shot, this is the most expensive weapon in the game, albeit the most powerful. It's also one of most inefficient, unnecessary, and impractical weapons in the game.

Fat Man was the codename for the atomic bomb that was detonated over Nagasaki, Japan by the United States on August 9, 1945. Because of its relation to the real historic event, the weapon was renamed to the Nuka Launcher in the Japanese version of Fallout 3. It is, however, still referred to as the Fat Man in dialogue.

Fallout 3 was originally being developed around the early 2000s by developer Black Isle Studios under the codename Van Buren. The game was an RPG similar to the previous installments played from a top-down view and would've used the engine from the canceled "Baldur's Gate III: The Black Hound". The game would've been set in the southwest of America and the story focused around a prisoner who escapes from prison and trys to discover why he was there in the first place and to stop a scientist named Presper from unleashing a virus to cleanse the world of non-pure blood humans. The project was canceled after Interplay had laid off the development team, however a tech demo was later leaked onto the internet.

In the Slaver Barracks of Paradise Falls, there is a Vault 77 Jumpsuit, with a Holotape right next to it. The Holotape is from a slaver who wants someone else to get rid of the jumpsuit that "a stranger with no name" left behind. The man recording the holotape is obviously scared and says the jumpsuit "freaks the boys out" so they must fear the stranger. The Vault 77 jumpsuit is the only one in the game and gives you a +5 to both unarmed and melee weapons.

All of these are referencing the Penny Arcade web comic "One Man, and a Crate of Puppets," which starred an unnamed Vault Dweller who was the only resident of Vault 77 and ended up hunting and killing Slavers with his bare hands and a Vault Boy puppet.

Through the use of cheats, it is possible to talk to Stockholm (the guard on top of the megaton entrance) who is usually inaccessible. When talked to, he will state:

Originally, President John Eden was meant to be voiced by former president Bill Clinton, but the team was unable to get him for the role.

After Spoiler: blowing up Megaton and encountering Moira after she becomes a ghoul, one of the player's dialogue options is "Honey, you got reeeal ugly!" This is a reference to Evil Dead 3: Army of Darkness, where Ash says this to Sheila.

In the Hubris Comics building is a letter to an editor on the receptionist's computer which includes a number of comic book references.



"Mr. Moorellis" is likely the combined last-names of Alan Moore and Warren Ellis, two well known English comic book writers.
"Mr. Neptura" is a reference to the character "Marto Neptura" in the comic Promethea, which was written by Alan Moore.

Just outside of Big Town, there is a utility pole in the exact center of the game map with a unique plate that reads "TES-04."

This is a reference to The Elder Scrolls IV: Oblivion, also by Bethesda. The placing of this pole in the map center likely suggests a reference to TES IV's most notable landmark, the White Gold Tower, which is considered to be the central point of the continent of Tamriel as well as the Imperial Empire in The Elder Scrolls games.

Sally from the Mothership Zeta DLC makes references to a fictional pre-war show called 'Captain Cosmos', which itself features classic Star Trek references, such as "All systems normal, Captain!" and "Captain on the bridge!"

She also mentions a female 2nd officer, saying "Stella Skyfire reporting for duty! She's Captain Cosmos' second in command, at least for the first few episodes..."
This is in reference to the original, unaired pilot episode of Star Trek: The Original Series, "The Cage", in which Captain Pike has a female lieutenant who is second-in-command, simply referred to as "Number One". NBC rejected this pilot and requested a new pilot episode, ultimately making her role as second officer last for only one episode.

Another notable reference is the time slot 'Captain Cosmos' airs at, which was Thursdays at 8:00PM EST, according to leftover posters in the Hubris Comics building. Star Trek:ToS aired on the same day but at 8:30PM EST.