As Fallout 4’s wastelanders explore more of the Commonwealth and get introduced to its factions, they’re bound to come into contact with post-war community members who, despite the hostility of the apocalyptic world, happen to be friendly. Totaling 15 individuals of different races, backgrounds, and dispositions, the companions can join the player in their adventures, provided the player helps them out first.
East of Diamond City, the player can find Cait prizefighting in the Combat Zone, a stadium for combat sports operated by some of Boston’s local raider factions. The player’s presence in the Combat Zone is enough to interrupt her fighting and attract the hostile attention of all raiders in the establishment.
After the player clears the Combat Zone of the raiders, Cait’s proprietor, Tommy Lonegan, will lament the loss of his audience, and offer the player a free buyout of her contract. Should they accept, Cait will join the player as a companion.
Cait, a long-term psycho addict, will eventually seek the player’s aid in kicking her substance abuse issues, starting the quest Benign Intervention. In this quest, the two visit Vault 95, located just northeast of the Glowing Sea, and fight their way through Gunners to reach a detox chamber that can near instantly clean her up. Completing this quest will grant the player the Trigger Rush perk while Cait is the active companion, which increases their AP recovery rate when below 25% of their maximum health.
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Codsworth is the player’s pre-war Mister Handy butler. He managed to wait out the initial 200 years of nuclear fallout at the player’s home in Sanctuary Hills, just down the hill from Vault 111, dutifully waiting for their return.
Built to serve, Codsworth will rejoin the player at the player’s request, without question. He will help in clearing out the rest of Sanctuary Hills during the quest Out of Time, after which he can permanently follow along as a companion. While traveling with Codsworth, the player will take less damage from the energy-based attacks of hostile robots.
Curie, a medically-equipped and scientifically gifted Miss Nanny, can be found in the secret disease-testing mole rat lab located in Vault 81 during the quest Hole in the Wall. She is in possession of the only dose of cure that is capable of healing Austin, a fatally ill vault dweller child. As long as the player can kill the mole rats that have trapped her inside the lab, she will grant them the cure.
Following this quest, Curie, fascinated by the outside world, offers to join the player in order to explore and learn more. This learning plateaus, however, when she feels that her lack of understanding for human emotions as a robot holds her back as a scientist. She suggests that the player help her find a way for her to inhabit a human body, starting the quest titled Emergent Behavior.
The two travel to the Memory Den in Goodneighbor, where Doctor Amari can transfer Curie’s consciousness into a synth body. Doing so will grant the player — and by extension, Curie — the Combat Medic perk, which will heal the player for 100 hit points if their health drops below 10% of its maximum.
Deacon is a spy affiliated with the Railroad, working to escort escaped synths out of Institute control and keep in-depth tabs on the Commonwealth’s happenings. When the player tracks the group down to their base of operations at the Old North Church, Deacon suggests that a person of their resourcefulness could be relied upon to carry out Railroad operations.
This starts the Tradecraft quest, which doubles as the introductory Railroad quest and Deacon’s companion quest. In it, Deacon takes the player to infiltrate the Slocum’s Joe located in Lexington, in search of a prototype device. The coffee shop, which had been the Railroad’s former base of operations, has since been overrun by synths, which must be dealt with in order to progress.
Following this quest, Deacon will offer to travel with the player full-time. When with the player, Deacon will give them the Cloak & Dagger perk, which increases the damage done by sneak attacks and causes stealth boy effects to last for longer.
As the lovable and iconic German Shepherd companion of Fallout 4, Dogmeat waits idly by the Red Rocket truck stop located just down the road from Sanctuary Hills. The player is instructed to greet them, and after an ambush by a few mole rats and some petting, Dogmeat faithfully joins their adventures as a companion. While they lack any companion-specific quests of their own, Dogmeat does contribute to the main quest-line, aiding Nick Valentine in tracking down Kellogg.
Hancock, the violent ghoul masquerading as a Revolutionary War soldier, is the mayor of the town of Goodneighbor. While Hancock’s influence overlooks nearly every quest happening within Goodneighbor’s walls, he doesn’t have any companion-specific quests to call his own.
Following the conclusion of The Big Dig, in which Hancock thwarts a plot for Goodneighbor citizens to steal from his personal weapons cache, he announces his hiatus from mayoral duties. After conducting a scripted speech from his balcony overlooking the town, the mayor offers his services to the player. Taking Hancock along provides players with the Isodoped perk, which grants increased critical hit charge rate in V.A.T.S. when the player is more than 25% irradiated.
Robert Joseph MacCready
The former mayor of Little Lamplight from the events of Fallout 3, MacCready is a former Gunner turned hired gun that the player can hire from within the Third Rail in Goodneighbor. For the price of 250 caps, or 200 following a speech check, he will join the player as a companion.
MacCready’s tumultuous past as a Gunner comes to a head with the Long Road Ahead companion quest. At his request, the player kills Barnes and Winlock, two Gunner commanders pushing him to return, at their hideout on the Mass Pike Interchange.
After his ties to the military company have been severed, MacCready then takes the player to Med-Tek Research. There, the two fight through ghouls to find a sample of the cure to his son’s disease. With his son’s life saved, he will grant the player the Killshot perk, applying a 20% boost when targeting an opponent’s head in V.A.T.S.
Nick Valentine is a second-generation synth turned detective operating out of Diamond City. The player is directed toward his office in order to request his services tracking down Kellogg. However, by the time they reach Diamond City, Valentine is being held captive by Triggermen in Vault 114.
Traveling to Park Street Station to the northeast of the city, the player fights their way through Triggermen to get to Valentine, defusing a confrontation with Skinny Malone, the leader of the group, to earn Nick his freedom. After doing so, they can meet back up with the detective back at his office to begin the Getting a Clue quest.
With Valentine’s help, the player gains access to Kellogg’s home, finding used cigar butts that can trace back to the man himself. After solving the case, however, Nick offers his services as a companion to the player instead.
The lone companion associated with Far Harbor, Longfellow is a seasoned hunter and mariner residing on the island. During the Walk in the Park quest, after the player steps off the boat and becomes acquainted with the people of the harbor, Longfellow offers to introduce them to the synth society of Acadia.
After these connections are established, Longfellow offers to stick with the player as a companion, acting as a guide to what the island has in store. His perk, Hunter’s Wisdom, reduces incoming damage from animals of any type.
An officer of the Brotherhood of Steel, the armor-clad Paladin Danse and his squad are found pinned down at Cambridge Police Station. Players can respond to their rescue signal by coming to their aid and fending off the incoming waves of feral ghouls. Doing so will start and complete the Fire Support quest.
After the player proves their worth in a fight, Danse will feel inspired to recruit them into the Brotherhood. The player’s introduction starts with a cooperative foray into ArcJet Systems in search of a replacement transmitter device, on a quest called Call to Arms. If this mission is successful, the player will be welcomed into the Brotherhood’s ranks, and by the time the Prydwen arrives in the Commonwealth, Danse will offer to serve alongside them as a companion.
Later on in the Brotherhood of Steel quest-line, it is revealed that Danse is actually a synth, putting his existence and Brotherhood affiliation is in direct opposition of the group’s values. Maxson, the Elder of the Commonwealth chapter, puts Danse’s fate in their hands. If the player can convince Maxson to spare Danse, the former Paladin will grant the player the Know Your Enemy perk, dealing increased damage to ghouls, synths, and super mutants.
Piper, a reporter writing for Publick Occurrences, Diamond City’s newspaper, can first be found having a heated argument with Mayor McDonough at the city’s gate. After interjecting on the quarrel between them, the player will draw her attention, primarily for looking and acting like a vault dweller. She invites them to an interview, starting the Story of the Century quest.
Later in Piper’s office, she’ll ask the player about their experiences living in the vault. Regardless of their answers, she’ll find the player and their journey fascinating, offering to tag along and cover whatever happens next. Having Piper as the active companion grants the Gift of Gab perk, which increases the experience gained when passing speech checks or exploring new areas.
When exploring the raider society developing at Nuka World, the player will come into contact with a raider named Porter Gage, who serves a diplomatic role between the three primary raider gangs — the Disciples, the Operators, and the Pack. The two hatch An Ambitious Plan to reclaim and occupy the entirety of the park, dividing ownership of its five zones between the three factions.
While the player muscles through the zones and clears out their hostile inhabitants, Gage makes sure all three gangs are on the same page and satisfied with their new territories. Gage also offers to help the player in the groundwork as a temporary companion, with his applied Lessons in Blood perk increasing the player’s damage resistance and experience gain while exploring the park.
Preston Garvey, the acting representative of the Commonwealth Minutemen, can be found holed up in Concord’s Museum of Freedom, staving off a group of violent raiders from attacking the last of his men. Should the player fend of the raiders and a sudden deathclaw sighting in the When Freedom Calls quest, Preston will get them further involved in defending other Minutemen-affiliated settlements from wasteland threats.
After helping their first settlement during The First Step, the player will be offered the rank of General within the Minutemen, and Preston will offer to take their side in combat as a companion. He applies the United We Stand perk, which substantially raises the player’s damage resistance and damage output when they are outnumbered three to one in a fight.
Strong is a super mutant that stands out from the rest of his peers for his appreciation of classical theater. Not quite as violent or aggressive as his militant race would suggest, the other super mutants stationed with him at Trinity Tower detained him, planning to execute him by throwing him off the building.
During the Curtain Call quest, the player can scale the tower, clear out its hostile super mutants, and rescue Strong from his cell. Once free of his captors, he indebts himself to the player, hoping that traveling with them can help him to find the fabled “milk of human kindness” that his stage plays speak of. No stranger to armed combat, Strong offers the player the Berserk perk, increasing their melee damage output when below a quarter of their maximum health.
A synth courser, X6-88 operates for the Institute, tasked with tracking down escaped synth experiments. If the player gets involved with Father’s Institute operations, they will cross paths with X6-88 when tracking down and returning runaway synths during Synth Retention.
After the player participates in The Battle of Bunker Hill in favor of the Institute, Father will express his plans to transfer the player into their position, making them the de facto leader of the Institute. Upon learning of the player’s involvement in Father’s chain of succession, X6-88 will serve them as a companion. His companion perk, Shield Harmonics, increases the player’s base energy damage resistance from all sources.