Fallout: New Vegas companions

Permanent companions
It is possible to have up to two legitimately acquired companions in the party (one humanoid and one non-humanoid). All permanent companions have a unique quest line that can be followed in order to "upgrade" them, usually giving them new armor or new perks.
 * Arcade Israel Gannon, a member of the Followers of the Apocalypse in 2281 who can be found in Freeside's Old Mormon Fort.
 * Craig Boone, a former NCR First Recon sniper with a grudge against Caesar's Legion. He can be found at night in the dinosaur at Novac. Can be recruited after completing One for My Baby and choosing particular dialogue.
 * Lily Bowen, a friendly nightkin and former assassin in the Master's army. She can be recruited in Jacobstown after gaining the quest Guess Who I Saw Today.
 * Raul Alfonso Tejada, a ghoul mechanic and former gunslinger held hostage by Tabitha, the mad leader of the State of Utobitha. Can be found in Black Mountain.
 * Rose of Sharon Cassidy (also known as Cass), a former caravan merchant and the daughter of John Cassidy. She can be found in Mojave Outpost.
 * Veronica Santangelo, a disillusioned Brotherhood Scribe. She can be found at the 188 Trading Post.

Non-humanoid companions

 * ED-E, a prototype eyebot designed for combat and reconnaissance operations. It can be found in Primm, in a non functional state, lying on the counter inside the Mojave Express, which is labeled in-game as "Nash Residence." ED-E requires 65 Repair (or 35 Repair if possessing a 55 Science skill) to fix it, or 3 pieces of scrap metal, two sensor modules, and some scrap electronics.
 * Rex, a cyberdog in Freeside under the ownership of The King. He is suffering from neural degradation as his old brain decays. He can be recruited after finishing Nothin' But a Hound Dog.

Dead Money companions
These companions are only available while playing the Dead Money add-on, they are only temporary and will not follow the Courier around as standard companions do:
 * Dean Domino, a ghoulified pre-War lounge singer. He is found in the Residential District of the Sierra Madre.
 * Christine Royce, a mute ex-Brotherhood scribe found in a malfunctioning Auto-Doc at the Sierra Madre medical district.
 * Dog/God, a nightkin found in the Villa police station of the Sierra Madre.

Honest Hearts companions
These companions are only available while playing the Honest Hearts add-on, they are only temporary and will not follow the Courier around as standard companions do:
 * Follows-Chalk, a novice scout for the Dead Horses tribe with wanderlust. He first accompanies the Courier for a while, before permanently returning to the Dead Horse's camp after a certain level of progress has been made.
 * Waking Cloud, the midwife of the Sorrows tribe worried about her husband. She accompanies the Courier upon Daniel's recommendation.
 * Joshua Graham, former Legate and reborn New Canaanite acting as war chief for the Dead Horses. He will only accompany the Courier either during the Flight from Zion final quest or the Crush the White Legs final quest.

Old World Blues companions
See temporary followers.

Lonesome Road companions

 * ED-E, a cloned version of ED-E, armed with a modified arc welder. This version of ED-E cannot follow the Courier to the Mojave Wasteland and is always classified as essential, even in hardcore mode.

Temporary followers
Temporary followers are NPCs that can accompany the player character during quests, or they might even offer their support only for a limited time or within a certain area. Unlike permanent companions, temporary companions do not use the companion wheel, do not heal automatically, and with the exception of Deputy Beagle, do not have an option to exchange equipment.
 * Deputy Beagle (during My Kind of Town)
 * Logan (during part of Wheel of Fortune)
 * Bodyguard (hired in Freeside)
 * Kings (hired in Freeside)
 * Orris (hired during G.I. Blues)
 * Big Beard and Little Beard (hired during the quest Bye Bye Love)
 * Ted Gunderson (during Beyond the Beef)
 * Cannibal Johnson (Enclave Remnant)
 * NCR Ranger (activated via NCR emergency radio)
 * NCR trooper (activated via NCR emergency radio)
 * Rhonda (during part of Crazy, Crazy, Crazy)
 * Private Halford (in Camp Guardian caves)
 * Securitron Mk II (or Securitron Mk I) (during No Gods, No Masters or All or Nothing)
 * Lost Mountain bighorner calf
 * Roxie (created in X-8 research center, will stay by your side, until you decide to leave)
 * Ulysses - the original Courier Six and significant character in Lonesome Road. Depending on the dialogue chosen, he will either become a temporary companion, or will become hostile.


 * Ulysses was also planned as a permanent companion, but was cut from base game.
 * Betsy the Brahmin was planned as a companion, but was cut from the game.

Nerve
Each companion also has a special attribute referred to in the game as Nerve. Nerve boosts the damage and Damage Threshold of each companion by 5% for each point of Charisma a character has. So Nerve grants a total bonus of +50% damage and damage threshold to companions with 10 Charisma and only +5% to both at 1 Charisma. A player character with a starting Charisma of 1 can boost their companion's nerve to the maximum by use of an Empathy Synthesizer, Intense Training, Party Time Mentats (+5), high Survival (so that alcohol adds +3 Charisma), or stacking moonshine with another type of alcohol. However, as Nerve is currently implemented, only the damage boost is ever applied to companions. Nerve also has a replacement perk given to companions only known as Companion Suite, however this too is bugged and does not work.

Quest Rewards
The following are quest rewards for completing each companion's quest.
 * Arcade Gannon
 * Gannon family Tesla armor Acquired at the end of For Auld Lang Syne if you tell Arcade to join the Second Battle for Hoover Dam. A Medium Armor set weighing 25lbs, with DT 32, 15 Radiation Resistance, and increasing the Energy Weapons skill by 10. It does however, also give -1 CHR, and if Arcade is given the armor he only wears it at the Battle for Hoover Dam.
 * Craig Boone
 * 1st Recon assault armor Weightless DT 15 armor, reward for I Forgot to Remember to Forget and convincing Boone to remain bitter.
 * 1st Recon survival armor Weightless DT 15 armor, reward for I Forgot to Remember to Forget and convincing Boone to accept the past.
 * Rose of Sharon Cassidy
 * Hand of Vengeance Perk providing +15% damage with Guns, reward for completing Heartache by the Number violently.
 * Calm Heart Perk providing +50 Hit Points, reward for completing Heartache by the Number peacefully.
 * Veronica Santangelo
 * Causeless Rebel Perk increasing Veronica's Unarmed attack rate by 30%, reward for completing I Could Make You Care by leaving the Brotherhood.
 * Bonds of Steel Perk providing +4 DT, reward for completing I Could Make You Care by staying with the Brotherhood.
 * Elijah's Last Words Perk providing +150% melee attack speed, 25% chance to knock down enemies with melee weapons. Can only be acquired by completing Dead Money and giving Elijah's holotape to Veronica.
 * Raul Tejada
 * Old Vaquero Perk providing +33% faster fire rate with revolvers and lever action firearms. Reward for completing Old School Ghoul, but only by convincing him to be a "vaquero".
 * Lily Bowen
 * Off the Meds Permanent stat bonuses, psychotic break at 50% health. Reward for convincing her to stop taking medicine.
 * ED-E
 * Brotherhood Examination Perk providing +8 DT.
 * Followers Examination New blue plasma-like weapon with +5 DAM, +8 DPS, +0.5% Crit Chance and +15 Crit Damage.
 * Camarader-E Both ED-E and the player gain +2DT, +5DMG with beam weapons, and +5% VATS accuracy. Acquired through Lonesome Road's side quest, ED-Ecated
 * Rex, depending on how you complete Nothin' But a Hound Dog can have one of these brains installed with the corresponding reward.
 * Rey's brain (+25 damage)
 * Lupa's brain (+10 DT)
 * Violetta's brain (+50% movement speed)

Player Perks
Two player perks can be selected that affects all companions.
 * Spray and Pray Reduces damage companions take from your weapons by 75%.
 * Ferocious Loyalty When you have 50% or less HP, Companions gain +50DR.

Companion Perks
Just by having a companion following you, you gain the benefits of their perk, which can also affect the entire party.
 * Better Healing:While Arcade is following, the party gains 20% better healing from any consumable.
 * Whiskey Rose:While Cass is following, the party suffers no negative effects from alchohol and gains a DT bonus from consuming it.
 * Enhanced Sensors:While ED-E is following, the party gains an increased detection radius(equal to 10 PER) and can not only target, but also gain a bonus to hitting, cloaked enemies in VATS.
 * Stealth Girl:While Lily is following, the party's Stealth Boys last twice as long, and gain 10% Stealth Critical damage.
 * Regular Maintenance/Full Maintenance: While Raul is following you the party's weapons degrade either 50% or 75% slower. Full Maintenance is only acquired by completing Old School Ghoul and convincing Raul to stick to being a mechanic.

Weapons
All permanent companions' default weapons have unlimited ammunition. If equipping followers with a better weapon, (DPS is checked) add ammunition and check its count from time to time - they seem to hold on to the new weapon when out of ammunition or switch to melee instead. Companions can use unique weapons with already built-in upgrades, such as the Ratslayer. Most companions use a weapon that's named after them. They share the same main characteristics as the standard version of the weapon and only differ in name, such as:

In regards to weapons, each companion has their own Strength limitations, they will suffer accuracy penalties just like the Courier if trying to use a weapon that has a higher strength requirement than they possess. Furthermore, depending on a companion's preferred weapon type, damage can be increased even further by buying improved ammunition, or crafting it with Hand Loader or Vigilant Recycler. Giving an energy weapons-user certain optimized ammunition types added with Gun Runners' Arsenal can influence their overall carry weight in Hardcore mode due to the ammunition's reduced weight. Finally, weapons given to companions do not lose durability unless hit directly by enemies, therefore high-damage and high-degradation ammunition types are usually preferable unless said ammunition grants the enemy x2-3 damage threshold multiplier.

Armor
Permanent humanoid companions can wear and/or carry all types of clothing that is not associated with any faction. They can also wear all types of armor and power armor that is not related to a faction, even without having the Power Armor Training perk. They only change gear if they are given gear that has a better Damage Threshold than their own outfits. This may not always hold true, however; giving multiple copies of the same outfit to a companion may result in them equipping an inferior copy, despite the difference in DT.

Companions will refuse to wear or even carry faction-specific apparel, except apparel corresponding to their own faction. Giving invalid faction apparel to a companion will result in that companion immediately dropping the item (see Bugs for errors that occur with this); it is not returned, but must be picked up from the ground. This also applies to non-human companions who cannot wear armor, i.e. Lily Bowen, Rex, and ED-E. Only Boone and Veronica are able to carry or wear faction apparel. As a former member of NCR First Recon, Craig Boone will carry or wear any NCR faction apparel. Veronica, as a member of the Brotherhood of Steel, will wear Brotherhood power armor. She will also accept apparel specific to the White Glove Society, and giving her the items White Glove Society attire or formal wear, will result in her teaching the unarmed move Scribe Counter. She will not wear these items, however, because their DT is inferior to her default clothing.

Behind the scenes

 * All companions in the base game initially had a basic concept design made by Joshua Sawyer, while individual writers fleshed out the characters and designed their dialogue, quests and other content.


 * Several remaining resources point to the game having at one point allowing the ability to have multiple humanoid companions. Primarily, this is found in disabled dialogue options, such as a conversation with Mortimer, where the Courier would have needed to specify which of their human companions they were offering to Mortimer.