Sole Survivor and Family | Companions (Main Story Companions) | Factions (The East Coast Brotherhood of Steel — The Railroad — The Institute) | Commonwealth Citizens (Diamond City — Goodneighbor) | Island Citizens | Nuka-World Citizens
- "Welcome to the great green jewel of the Commonwealth. Safe. Happy. A fine place to come, spend your money, settle down."—Mayor McDonough
The largest settlement in the Commonwealth (following University Point's destruction and not counting the relatively secluded Vault 81), located inside the relatively intact Fenway Park. It owes its security to both "the Wall" and its trigger-happy security force at the service of the Mayor.
- Brand X: Despite the city being built out of Fenway Park, and baseball gear being omnipresent in the city lore (from guard outfits, to the store selling bats for defense, to the bases marking intersections), there's not a mention of the Boston Red Sox by name. This was likely because Bethesda couldn't secure the rights to the team's brand. All uniforms thus conveniently lack the team logo while keeping to the red and white color scheme.
- Crapsaccharine World: What society in Diamond City is like at its most optimistic. If you remove the constant Institute paranoia and institutionalized bigotry against Synths (and to a lesser extent, Ghouls), it's otherwise one of the biggest and most stable bastions of civilization the Commonwealth currently has.
- Crapsack World: Despite their claims of being otherwise, they're ultimately closer to Rivet City and Megaton than New Vegas and Shady Sands in terms of living standards. For one, its citizens still live in makeshift metal shacks built on top of the stands rather than the largely stable buildings found outside due to the surrounding cityscape being a chaotic warzone. There's a school, a bar and a church - but these are the height of the luxuries on offer, with dredging the city water supply for garbage still yielding the occasional human skull. The town also appears at first glance to be safe from destruction despite the near-constant battle fought outside between its guards and the Raiders/Super Mutants, but this is a subversion. Diamond City once had a gaping hole in its defensive wall covered by nothing more than a bookcase until Piper Wright published an article about the danger to spur action to fix it. Generally, the city itself is much more vulnerable than its people or mayor are ready to admit.
- Fantastic Racism: They hate Synths (Except for Nick Valentine, although some civilians do still hate or distrust him) and Ghouls. The mayor was even elected because he led a pogrom against the latter to drive them out of town and kill those who remained behind. This was done under order of the Institute to make sure no one with Pre-War knowledge remained in Diamond City and thus could make the city become a threat to them. It's worth noting, though, that the Mayor was democratically elected, so its citizens aren't exactly blameless in this either.
- Foil: To the New Vegas Strip, as alluded to above. Both cities sell themselves as functional oases of progress and civilization from the surrounding Wasteland, but New Vegas is obviously more advanced and far safer than Diamond City is. However, New Vegas ultimately comes across as a glorified tourist trap due to its overabundance of casinos and lack of societal institutions, while Diamond City is an actually functioning settlement and city-state.
- Future Imperfect: While the citizenry by and large have an appreciation of baseball, not everyone it seems has a good grasp on how it was actually played.
- Jerkass: The unnamed residents of Diamond City aren't the friendliest people in the world, often responding rudely to the player's interactions. Justified in that pretty much everyone is on edge about the possibility of Synth spies infiltrating the city. They become much nicer after you purchase Home Plate.
- Police Are Useless: Diamond City Security will not intervene if a Triggermen hit squad is sent after the player. Piper will also deride the security forces as ignoring kidnappings and missing persons, because they've been ordered by the Mayor to not waste their time on such things.
- After the Institute ending, Synths show up in Diamond City actively spreading pro-Institute propaganda, and, presumably, were the ones hanging up Institute flags around the city. Diamond City Security admits they have no idea what to do about it, since they technically aren't doing anything wrong, despite pretty blatantly setting Diamond City up for The Coup. Possibly Justified in this case, however; Mayor McDonough, who is an Institute synth, likely told them to stand down.
- Police Brutality: Diamond City Security is heavily armed, and are known to not mess around. especially if the subject of Synth infiltrators or the Institute is brought up. On the player's first visit, a man who holds his brother at gunpoint (suspecting him of being a Synth) is executed by security without them doing even a token effort at talking him down. It's implied security cares more about keeping the city safe from outside threats and internally peaceful than actually providing justice or policing or making people feel safe. It's why Nick's business is booming.
- Shown Their Work: Several features from the Real Life Fenway Park are modeled in the game:
- The scoreboard which Diamond City residents revere as "The Wall" is a real feature of Fenway Park's design. Its real nickname is "The Green Monster." Its shade of green has become Diamond City's de facto color.
- In the real life Fenway Park, there is a large Coca-Cola sign approximately in the same location and style as the Nuka Cola sign in game.
- There is a single red seat in the bleachers, representing where Ted Williams hit the furthest ball in Fenway Park history, 502 feet from home plate.
- Suspiciously Similar Substitute: To Megaton, albeit Diamond City's much more stable and organized. Also, they can be seen as one to Rivet City and even New Vegas (to a much lesser extent).
- Token Heroic Orc: Despite being very anti-Synth, Nick Valentine is largely accepted by Diamond City because he's heroic and helpful.
- Town with a Dark Secret: It gives shades of this, as disappearances go uninvestigated by security. The subject of Synth infiltrators and the Institute is borderline taboo and known to rile up security. Seeing as the mayor is a Synth infiltrator himself and he's been using his position to deflect any attention to the Institute's actions. Thankfully Piper is around.
- Urban Segregation: The rich have their houses in the Upper Stands, while the poor live down in the field. The Colonial Taphouse will only serve Upper Stands residents, and in fact runs radio ads telling people who are not Upper Stands residents how they are not welcomed.
The mayor of Diamond City, elected on a strong anti-Ghoul platform. Ironically, his brother, John Hancock, is a Ghoul. He does not like Piper and her investigative journalism.
- 0% Approval Rating: Aside from Diamond City Security, no one really seems to like him. After his "I Am Not A Synth" speech and everyone politely claps, a few Diamond City citizens can be heard muttering "He's so full of shit."
- Asshole Victim: His racism is one of Bobbi's reasons for robbing his warehouse in the mission "The Big Dig", although she admits that money is still her primary motivation. Although it turns out that Bobbi is actually robbing Hancock's warehouse, not Mayor McDonough's. Played straight if the Sole Survivor kills him at the conclusion of "In Sheep's Clothing".
- Blatant Lies: He keeps talking about how there are no Synths in Diamond City, even as it becomes hugely obvious that this simply isn't true.
- Cain and Abel: While he never gets his hands dirty, he's definitely quite a bastard compared to his brother.
- Dead All Along: The real McDonough is long-gone, now replaced by the Synth double you meet. If Hancock is present when he's exposed, he wonders to himself exactly how long ago did they take his real brother.
- Expy: He's pretty much a far less competent Wasteland version of Richard Nixon. In fact, his "I Am Not A Synth" speech has a line by line reference to Nixon's "I Am Not A Crook" speech. Like Nixon, he's also participating in illegalities and cover-ups, due to him being a Synth infiltrator trying to discredit the idea of the same to protect himself.
- Fantastic Racism: Kicked all of the Ghouls out of Diamond City, where they were forced to move to Goodneighbor. John Hancock and Bobbi both despise him for this. Given that he's a Synth doing the Institute's bidding, it's part of a deliberate attempt to deprive Diamond City of anyone with first-hand knowledge of the Pre-War world.
- Fat Bastard: One of the more rotund individuals encountered in the Commonwealth, and is just plain corrupt.
- Foil: To Mayor John Hancock of Goodneighbor. Both men are the respective leaders of their towns, but while Hancock runs a town of societal dregs, they are genuinely happy with each other and have a much better handle on the paranoia of the Institute. By contrast, Diamond City may be the town of the "decent people", but it's a paranoid place that tried to pretend synths don't exist and has a lot of societal backstabbing going on under the surface. It makes more sense when it's revealed that McDonough is Hancock's brother.
- Foreshadowing: A very subtle case. The next time he yells for Piper to leave the mayor's office, his voice gains a noticeably mechanical cadence and louder tune, alluding to him actually being a Synth infiltrator.
- Relatedly, his constant Verbal Tic concerning him mentioning that he's the Mayor every few sentences can be seen as a sign of him having faulty programming as a Synth and trying to sell the illusion of being human.
- He's very unpleasant to Piper, who simply wants to investigate the Institute (well, that and her accusing him of being a Synth in her newspaper). He's also openly racist against Ghouls, having kicked them all out of Diamond City years ago.
- According to his brother, John, he was an abusive bully as a kid too.
- He's also an Asshole Victim, given that his Synth doppelganger isn't much better.
- Mayor Pain: Turns out to be the evil variety due to being a Synth infiltrator for the Institute and throwing out the Ghouls of Diamond City so as to remove Pre-War knowledge from the city. This is in sharp contrast to his brother, who very competently handles Goodneighbor.
- Mole in Charge: He's revealed to not only be this for the Institute, but also a Synth as well.
- Not Worth Killing: An Institute computer log indicates that McDonough has nearly outlived his usefulness to the Institute and is due for decommissioning soon. However, they don't even consider him valuable enough to retrieve or important enough to decommission before his cover is blown. They fully expect him to be eventually outed as a Synth, and to last for two weeks maximum after that before being killed by something on the surface. The Institute (predictably) chose this natural outcome as the most cost-effective way to decommission him.
- Only One Name: His first name is never mentioned.
- Pet the Dog: A entry on his terminal reveals he ordered Diamond City Security to stop trying to take over Sheng Kowalski's water business, admiring the young man's entrepreneurial spirit.
- Of course, considering that, under Kowalski's management, the water supply has everything from grenades to human skulls in it, this may just be part of his synth programming meant to undermine the city...
- Small Name, Big Ego: While he's the mayor of the biggest, safest surface settlement in the Commonwealth, he still oozes an aura of puffed-up self-importance (not helped by the fact that he keeps mentioning "I'm the mayor!"). All of his "updates" to the Institute are extremely self-serving requests for them to do stuff that threatens his position as mayor. Institute data logs indicate that his real masters consider him expendable, and that he's requested to become a Courser when his job as mayor is over. Merely asking that question indicates to the Institute that he has way too much self-determination to be a Courser. Furthermore, he's modeled after an overweight old man that wouldn't even fit into the uniform.
- Verbal Tic: Can't seem to go more than three sentences without mentioning that he's the mayor. He even screams "I'm the mayor, dammit!" during his Villainous Breakdown.
- Villainous Breakdown: Should the Sole Survivor becomes an enemy of the Institute or having destroyed it, the synth McDonough becomes real upset when he's informed by a synth contact that the Institute has decided to abandon him. It gets even worse for him that he has been eavesdropped by one of Diamond City's security guards, causing him to shoot said guard and taking his secretary hostage inside his office.
Merchants and Vendors
Vadim and Yefin Bobrov
Twin brothers and co-Owners of the Dugout Inn.
- Disproportionate Retribution: Vadim tries to hire the player to kill Travis because he makes the radio terrible. He's actually only joking and is, in fact, a good friend of Travis who worries about his lack of assertiveness.
- Heterosexual Life-Partners: The are brothers, after all. Bicker as they might, blood's thicker than water.
- Husky Russkie: Vadim is a large, boisterous man who's also big into bar brawls.
- Ink-Suit Actor: Vadim rather strongly resembles his voice actor. Oddly enough, Yefim does not.
- Polar Opposite Twins: The two men look exactly alike, but their personalities couldn't be any more different. Yefim is a reserved man of few words and prefers to stay out of other people's business; Vadim is a loud, hearty sort who's not afraid to speak and act on whatever that comes into his mind with reckless abandon.
- The Mafiya: They have shades of this, being Russian guys who are involved in some shady stuff. Except for a debt he owes to some unsavory types, it's all mostly just an act.
- The Matchmaker: Vadim knows that Travis and Scarlett, the inn's waitress, have a thing for one another, but he can't tell her to just ask the shy Travis out because he's her boss and it'd come off wrong.
- Nice Guy: Vadim is very amiable, and when his employee Earl Sterling disappears, he hires Valentine to find him. Vadim also concocts a scheme to induce Travis to grow a spine because he's done standing by and watching Travis be so pitiful (part of which is setting him up with his waitress, Scarlett).
- Noodle Incident: "You see this bar? I kill a man for it! Hahaha, I kid, I kid. ...he is dead, though..."
- Red Oni, Blue Oni: Vadim is the boisterous red to Yefim's reserved blue.
- The Storyteller: Vadim can be counted on for drunken tales, such as the one where he fought a Mirelurk off naked. Yefim, as always berates his brother for these.
- Unexplained Accent: They are the only people with Russian accents in the city, let alone the entire game and their origins are never explained.
- Vitriolic Best Buds: They might not get along... ever, but they are brothers and still care for each other.
The owner of the Colonial Taphouse, having an affair with Darcy Pembroke. In order to resolve the problem peacefully, he suggests to raid a chem factory.
- But Now I Must Go: If you help him to raid the chem factory, he'll leave the Commonwealth and is nowhere to be found.
- Leave No Witnesses: If you bring him to ambush the chem trade, he will gun down Trish, the chem dealer, after you interrogate her about the chem factory's location and password.
- The Mole: Terminals in the Institute Synth Retention Bureau list him as one of their informants on the surface. Which might explain why he's so eager to leave the Commonwealth after the chem deal.
- Nothing Personal: He claims that there's nothing personal when he shoots Trish.
- Shotguns Are Just Better: Cooke is usually seen packing a double-barrel.
The owner of Diamond City Surplus.
- Cloud Cuckoolander: She's extremely paranoid and accuses everybody she speaks to of being a synth, much to the annoyance of her customers. Also, unlocking her computer shows a list of people in town she suspects are synths, which accounts for most named NPCs living in Diamond City. She thinks Piper is writing articles to divert the idea that she could be a synth, while Moe Cronin could be a synth because "only synths like baseball". She also believes Arturo Rodriguez to be a synth because he's "too nice"; Abbot to be a synth because he's "too mean". Solomon is a synth according to her, and she feels he pretends to be "high all the time". Piper doesn't call her Crazy Myrna for nothing.
- Fantastic Racism: She absolutely refuses to serve synths (she won't even serve Nick Valentine). Because she also accuses everybody of being a synth, it's a wonder that she gets any business.
- The Cuckoolander Was Right: Mostly averted, but it turns out that at least one other Diamond City resident besides Nick Valentine is a synth. It's the Mayor.
The owner of Commonwealth Weaponry - also a contact for the Railroad.
- Beware the Nice Ones: Arturo's a really nice guy...who just happens to own a lot of guns, including a Fat Man that fires two mini nukes simultaneously.
- Dashing Hispanic: He's quite good-looking and speaks with a latino accent.
- Gun Nut: He seems very knowledgeable when it comes to weapons, and he's often heard talking to his customers about the advantages certain weapons have over others in different situations. Also, it's the name of the perk related to modifying guns.
- The Mole: For the Railroad. He's one of their contacts, and Deacon can be seen striking up a conversation with him in cryptic phrases and code words.
- My God, What Have I Done?: Arturo feels partly to blame for the fallout of Mayor McDonough being revealed as a synth; he sold McDonough the gun that he used to shoot Danny Sullivan and hold Geneva hostage.
- Nice Guy: Easily one of the nicest people in the Commonwealth.
- Parental Neglect: In his house, there's a little play and study area for his daughter, Nina. Toys you kind of expect, but you know what else is in his daughter's play area? A pipe gun. Not to mention that he keeps a mini nuke in his house! Then again, when one considers the fact that he runs Diamond City's gun store and his dialogue indicates a deep understanding of firearms, it's likely if not a given that Nina has been taught how to safely handle it. This is the Commonwealth, after all.
- Unexplained Accent: He has a Hispanic accent with little explanation of his origins.
The owner of Swatters, and a so-called "baseball" enthusiast.
- Batter Up!: His entire store, life and personality is based around this. He even carries a unique bat called the Rockville Slugger and will buy the 2076 World Series Bat from the player for 200-400 caps.
- Bitch in Sheep's Clothing: By day? he's a jovial baseball enthusiast and salesman of baseball gear. Once he's off the clock? He refuses to give anyone the time of day, and is exceedingly rude.
- Cloud Cuckoolander: Not to the extent of Myrna's paranoia or Dr. Duff's forgetfulness, but he genuinely believes that baseball is a bloodsport that involves such things as two teams beating each other to death with bats, catching bullets with baseball mitts, giving baseballs to the children of players that were killed and even playing the game wearing power armor.
- I Reject Your Reality: You can explain to him that baseball isn't what he thinks it was, but he doesn't believe you.Moe: (after being told what baseball really was) "...I like my version better."
- On the flip side, you can tell Moe that baseball was even bloodier than he thought. His response? "...I like my version better."
- Shout-Out: He's named after famous Boston baseball players Moe Berg and Joe Cronin.
When he can stand being around his patients, the city doctor.
- Annoying Patient: Will always treat the Sole Survivor like one.
- Deadpan Snarker: Sun has three expressions: Irritable, exasperated and irritably exasperated.
- Dr. Jerk: He derides absolutely everyone he comes across, but he takes his profession very seriously.
- Failed a Spot Check: During "The Disappearing Act," he doesn't seem to notice the very obvious blood stains leading to the cellar.
- Good Is Not Nice
- Red Herring: During the quest to find Earl Sterling, he's weirdly hesitant to let anyone investigate the clinic basement - giving the impression he's covering up Doc Crocker's accidental killing of Earl; mocking the very notion once he realizes what the player thinks has happened. He was legitimately oblivious to the whole thing.
- Surrounded by Idiots: Constantly acts like he's this.
The city's other doctor who specializes in plastic surgery.
- Appearance Angst: The catalyst of his accidental killing of Earl was the latter going through this.
- Beauty Equals Goodness: Has this mindset. It's implied he looks down on uglier people.
- But Thou Must!: Even if you manage to peacefully talk him down, Crocker still dies at the end of "The Disappearing Act" VIA a Psycho overdose.
- I Didn't Mean to Kill Him: Crocker was too obssessed with fixing Earl's face to worry about HOW he was fixing it.
- Morally Ambiguous Doctorate
- My God, What Have I Done?: If the Sole Survivor talks Crocker down during "The Disappearing Act", he has this reaction and doesn't take it well.
The laid-back proprietor of Chem-I-Care.
- Drugs Are Good: One of his store's selling points is how Chems "even you out." See also his store's motto: "A balanced life through chemistry."
- New-Age Retro Hippie
- Only Sane Man: Implied to see himself as one to everyone else, snarking about how everyone's "jumping at shadows."
- Right for the Wrong Reasons: Hates how everyone in Diamond City is a paranoid mess "jumping at shadows." While Diamond City is certainly a hive of paranoia eating itself away, it has good reason to be.
A Protectron robot that works as the cook at Power Noodles. Only says one thing.
- Bilingual Bonus: "Nan-ni shimasho ka?" roughly translates to "What would you like?"
- Expy: Of another robot restauranteur from Blade Runner.
- Intelligible Unintelligible: Is somehow able to communicate with Codsworth, and apparently laments his malfunctioning voice modulator. Codsworth comforts him with the hope that a replacement part might eventually turn up.
- Tuckerization: It's speculated that he was named after Tetsuya Takahashi, another Japanese game designer whose also responsible for the Japanese localization of Fallout 3.
- Verbal Tic: Only says one thing: "Nan-ni shimasho ka?"
An orphan kid who runs the water purifier and sells purified water. Unlike most kids, he goes to school at night.
- Abhorrent Admirer: Tried to kiss Nat Wright at one point and got a punch in the face for his troubles.
- Bad Boss: Once hired another wastelander to clean up his water but didn't warn him about a live grenade and got killed as a result.
- Bratty Half-Pint: He often looks down on the player for not being a successful businessman and cusses them out if they don't buy any water from him.
- Honest John's Dealership: If you don't care that there might be items such as a skull in the water, he has the only purified water in Diamond City.
- Repeating Ad: If Travis dies for whatever reason, he'll take over the radio station and will constantly advertise his water business.
Natalie "Nat" Wright
Piper's little sister, who follows in her footsteps by helping sell newspapers.
- Big Sister Worship: Piper actually worries that Nat might grow up to be exactly like her — treading the same, devil-may-care lifestyle as she does.
- Cheerful Child: She mainly takes after her sister, showing the same bright, optimistic outlook on life.
- Children Are Innocent: Although it's implied that she's already pretty aware of the darker aspects of society, if her "information talks" are anything to go by.
- Disappeared Dad: Their father was murdered long before the story begins.
- Strong Family Resemblance: She looks a lot like a younger Piper.
The DJ of Diamond City Radio and news broadcaster for the game.
- Bunny-Ears Lawyer: He is about the worst person in the world to be doing the 1950s music and news station for a variety of reasons. Despite this, he remains completely dedicated to doing it.
- Comically Missing the Point: When he talks about the songs he plays, he sometimes seems unaware their lyrics are ironic or metaphorical.
- Confidence Building Scheme: One of the sidequests in the game - appropriately named "Confidence Man" - sees the Sole Survivor team up with Vadim Bobrov to help Travis gain confidence. Methods used include as helping him win a bar fight and convincing a waitress he's interested in to spend time with him; the quest eventually concludes with Travis helping to rescue Vadim from the raiders - and admitting that his experiences have really helped develop his self-confidence. From then on, his radio broadcasts are delivered in a much more relaxed style.
- Corpsing: He is is audibly struggling to hold back his laughter whenever he announces that the next song is "Rocket 69".
- Dead Air: His program is plagued with it, due to him hesitating nervously or while thinking of something to say next. He hasn't yet worked out that he can use songs to cover gaps in the broadcast.
- Dude, Not Funny!: In-universe; His general reaction to the songs he plays on his radio, since a lot of them have radiation, uranium, and nuclear-war related themes (as part of Bethesda's in-joke, obviously). Travis has to play them, though.
- To Three Dog from Fallout 3. Whereas Three Dog is a charismatic Rebellious Rebel and a good example of Large Ham Radio, Travis is a nebbish, nerdy kind of guy without much radio presence. He's prone to halting, stuttering, and indecision. He also struggles not to offend anyone with his broadcasts while Three Dog praised or insulted individuals without any concern for how they'd feel about it. Helping him build up his confidence changes this, however. Afterwards, he starts behaving more like his Capital Wasteland counterpart — even quoting Three Dog if you complete the game with the Minutemen or the Brotherhood, where he says "Always fight the good fight."
- He's also one towards the charismatic and sociable Mr. New Vegas from Fallout: New Vegas. Where Mr. New Vegas is the charismatic man who has many fans and receives lots of fanmail, Travis is socially awkward and states on several occasions that his station is struggling to stay on air due to not earning a lot of caps. His reporting style is actually similar to New Vegas in that he tries to be mostly impartial and report the news as is. Upon gaining confidence, he even starts channeling the man himself somewhat.
- Within Fallout 4, he's this to RedEye from the Nuka-World DLC. Travis is very honest, meek, shy, and self-doubting (pre-"Confidence Man", anyway), whereas RedEye is a Raider, and thus is violent and sociopathic, as well as a notorious bullshitter. In addition, Travis plays classic '50s music, whereas RedEye sings his own songs about the joys of being a Raider.
- Is This Thing Still On?: When he reports on the Brotherhood's arrival in the Commonwealth, he completely fails to conceal how terrified he is by the prospect or the moment he panics, turns away from the mic and says "We're all gonna die!"
- Repeating Ad: He'll often advertise one of the local businesses of Diamond City on the radio.
- Suddenly Shouting: His pre-"Confidence Man" persona does flips occasionally.
- The Last DJ: Averted. It's clear Travis is playing what people want to hear, for whoever's ordering him around, and doesn't even much care for the music.
- Took a Level in Badass: Vadim's plan to improve the radio revolves around this: get Travis to win a bar brawl and feel like a badass. It doesn't entirely work... but when the guys Travis and the Sole Survivor beat up (or their Raider buddies, if they die in the fight) kidnap Vadim, Travis volunteers to go save him, and the experience changes him, making him very assertive and a much better DJ.
- Worst News Judgement Ever:
- Inverted as he dances around and struggles to inform people of really important news (like the Reformation of the Minutemen, the Brotherhood of Steel coming from the Capital Wasteland, and so on) without giving his personal opinion on the subject. He also obviously thinks the Minutemen returning is a huge deal and amazing for everyone, but tries to sound neutral.
- Averted after his personal quest. From then on, he'll give much more detailed and relevant commentary on the news.
Nick Valentine's secretary.
- Deadpan Snarker: Seems to take after her boss in this department.
- Expy: She's one to Effie Perrine, the secretary to private detective Sam Spade.
- Girl Friday: She's this to Nick.
- Hypercompetent Sidekick: She's as good at running the office as Nick is at being a detective.
- Platonic Life-Partners: There's no romantic involvement between the two, but they are very close.
Associate residing in the Science! Center.
- Absent-Minded Professor: Agree to get a Bloatfly gland for her, and she'll actually forget who the Sole Survivor is when they return to her lab until they show her said gland.
- Ambiguously Gay: There's only one bed in the Science Center, her fellow researcher Professor Scara refers to her as "dear", and mentions being Exiled to the Couch after an argument. When Duff tells you she's worried about Scara as she's been away on a field trip for much longer than usual, a little digging gets her to tell you that they're "very close". If Scara leaves to work on Liberty Prime with the Brotherhood, Duff will become depressed.
- Genius Ditz: A brilliant yet utterly oblivious scientist.
- Genki Girl: She might as well be the twin sister of Moira Brown who got into science instead of selling and fixing junk.
- Insult Backfire: If you're sarcastic with her after she prattles on about radiation-resistant animals.Sole Survivor: You are one huge nerd.
Dr. Duff: I, for one, take that as the highest compliment!
The pastor who runs the All Faiths Chapel near the front gates of Diamond City.
- Good Shepherd: He accepts all comers of all faiths equally (as indicated by the name of his church) and provides them with comfort and hope. The Sole Survivor can even rest for a moment at his church to receive a small temporary experience boost.
- Nice Guy: One of the nicest and most nonjudgmental people in town. He'll even perform a wedding between a man and a robot since he believes everyone deserves a shot at true love and happiness.
- Preacher Man: He serves as this for the people of Diamond City. He even wears a Pastor's Vestments outfit, which is one of the rarer clothing items in the game.
A grumpy man with relationship trouble, he suspect his wife was cheating with Henry Cooke.
- Curb-Stomp Battle: He attempts to knock Cooke out do dissuade the latter from having an affair with his wife. He gets knocked on his ass for it, which is where you potentially come in.
- Karmic Death: If you didn't kill Henry and you told Colette that Paul killed her father, he will be gunned by her, and consider that he lied to her, proclaiming that you killed Henry, one may say it's deserving to return his favor by another lie.
- Took a Level in Jerkass: He starts out as a grumpy man with relationship troubles, but eventually, if you made a deal with Henry to raid a chem factory and either not informing Paul or giving him a 70-30 share instead of 50-50, he begins treating the Sole Survivor with great disdain no matter whether Henry ended up alive or dead. He outright lies to Henry's daughter, Colette, that you killed her father.
- Took a Level in Kindness: On the flip side, if you do give him the 50-50 share, he'll be less grumpy and will treat you as a good friend as he takes over the Colonial Taphouse. He also sells various chems in his new shop.
The daughter of Henry Cooke. She comes into town searching for her missing father, a few in-game days after the conclusion of the "Diamond City Blues" mission.
- Prank Date: She asks the Sole Survivor for a date in order to find out who killed her father, or her father's whereabouts if he's alive.
- Roaring Rampage of Revenge: Henry's sudden disappearance leads her to go after you. Should you convince her that Paul was the one who killed him, she guns down Paul off screen.
- You Killed My Father: The driving force behind her vendetta against you, if you finished the mission in a certain way. Otherwise, she doesn't have anything against you or Paul.
A bum who spends his days sitting in the Diamond City market and asking passersby for a Nuka Cola.
- Addiction Displacement: His idle dialogue implies he started drinking Nuka Cola after his booze habit started affecting his health."I gave up alcohol after settling down here. Doctors said I shot my liver."
- The Alcoholic: He used to be one, but has since given it up for Nuka Cola.
- I Can't Believe It's Not Heroin!: Just replace "Nuka Cola" with "crystal meth" and his addict routine makes a lot more sense.Sheffield: "Cooola. Need a Nuka Cola!"Sole Survivor: "Drink. Some. Water."Sheffield: "Nuka Cola!" *whimpers*
- Must Have Caffeine: He claims the caffeine in Nuka Cola helps him think straight.
- Trademark Favorite Food: Guess.
- Videogame Caring Potential: If the player gives him a Nuka Cola, he can be recruited to a settlement and be given a job.