Fallout: New Vegas companions

Base game

 * Companions are special non-player characters who follow the player, aid them in combat, and provide a unique perk as long as they're in the player's party (whether following them or waiting; the perk stops applying when they're dismissed). Companions are controlled via the Companion wheel.
 * The player can have one humanoid and one non-humanoid companion (Rex or ED-E) in their party at a time, with both providing their unique companion perks (unless using exploits). If the player already has a companion of a specific type, they need to be dismissed through dialogue. Then they will either return to their original location (except for Raul) or can be told to go to the Lucky 38. Unlike Fallout 3, companions are moved to their target locations instantly.
 * Companions will take and use consumables if left to their own devices, especially at the Lucky 38. The player can also place stimpaks in their inventory to prolong their longevity.
 * Every companion can be upgraded by completing their corresponding personal quest.
 * Few of the companions are available from the get go and most will require some legwork to recruit. The game ignores karma when recruiting followers, although it can test against the player's faction reputations. Recruiting all eight companions in one game will grant The Whole Gang's Here trophy/achievement.

Temporary followers
These followers accompany the player only in specific areas or for a limited duration of time. They are listed alphabetically:
 * Body guard, hired in Freeside.
 * Cannibal Johnson, one of the Enclave remnants.
 * Deputy Beagle, at Primm during My Kind of Town.
 * Joana, at Gomorrah during Bye Bye Love.
 * Logan, during the final part of Wheel of Fortune.
 * NCR Ranger and NCR Trooper, when called in through the NCR emergency radio.
 * Neil, during a part of Crazy, Crazy, Crazy.
 * Orris, hired in Freeside while investigating his crooked business.
 * Private Halford, while investigating the lost NCR outpost, found in Camp Guardian caves.
 * Rhonda, briefly during the last part of Crazy, Crazy, Crazy.
 * Securitron Mk II or Mk I, at Hoover Dam during No Gods, No Masters or All or Nothing.
 * Sunny Smiles, at Goodsprings during Back in the Saddle, By a Campfire on the Trail, and Ghost Town Gunfight.
 * Ted Gunderson, at Ultra-Luxe during Beyond the Beef.
 * Victor, during We Must Stop Meeting Like This and We Must Stop Beating Like This.

Cut followers
The player was supposed to be able to gain a seventh humanoid follower:
 * Ulysses, the first Courier Six. He was cut from the game and later reused as the antagonist of Lonesome Road.

Dead Money
The Dead Money DLC introduces three companions who play a crucial role in the story unfolding at the poisonous Sierra Madre.
 * Dean Domino, a ghoulified pre-War singer with dark ties to the Sierra Madre. He is located in the Madre's residential district.
 * Knight Christine Royce, a Circle of Steel assassin who was rendered mute by wounds suffered at the Madre. Found trapped in an Auto-Doc in the medical district.
 * Dog/God, a nightkin with a split personality and slave of Elijah. Found in a cage at the Villa police station.

Honest Hearts
The Honest Hearts DLC introduces three companions who will accompany the player during the storyline, one per act.
 * Follows-Chalk, a Dead Horses scout novice possessed by an exceptional wanderlust. He accompanies the player from the start of the story until meeting Daniel, then retires to the Dead Horses' camp.
 * Waking Cloud, a Sorrows midwife who aids Daniel in his work. She will accompany the player as they collect the tools necessary for the Sorrows to prepare to leave Zion.
 * Joshua Graham, a New Canaanite who fell from grace and became Caesar's first Legate, only to return to New Canaan as a prodigal son. He accompanies the player during the final two quest, Flight from Zion or Crush the White Legs.

Old World Blues

 * Roxie, a cyberdog assembled by the player at the X-8 research center.

Lonesome Road

 * ED-E, a version of the original ED-E constructed at the Hopeville missile silo after it was scanned by the Divide's sensor network. Essential part of the storyline.

Nerve

 * Note: In the latest version of Fallout: New Vegas'' Nerve appears to have been completely disabled. The following is a description of Nerve as it's supposed to work.

This special attribute reflects the player's influence on their followers. Tied to Charisma, Nerve boosts a companion's damage output and Damage Threshold by 5% per the player's character Charisma score. I.e. a Courier with 1 Charisma will give their companions a +5% bonus to each, while at 10 Charisma it will be a whooping +50% bonus. Nerve synergizes with Ferocious Loyalty and Spray 'n Pray, greatly increasing companion resilience.

Nerve depends in the current Charisma score and takes into account any active bonuses. As such, even with a starting Charisma of 1, it's possible to obtain the top Nerve bonus by boosting the player character's Charisma to 10 through a combination of bonuses: Empathy Synthesizer at the New Vegas Medical Clinic (permanent +1), Intense Training (permanent +1 per level), Party Time Mentats (temporary +5), alcohols (temporary +3 with a high Survival) and/or stacking them with moonshine.

Not all companions benefit equally from Nerve. Some gain bonuses that combine with Nerve to make them a lot more effective. These include:


 * Cass, with Hand of Vengeance (15% more damage with Guns) or Calm Heart (+50 Hit Points).
 * Veronica Santangelo, with Causeless Rebel (Increases her Unarmed attack rate by 30%; Nerve's increase to base damage results in a major boost to DPS) or Bonds of Steel (+4 DT), and Elijah's Last Words (+150% melee attack speed, 25% chance to knock down enemies)
 * Raul Tejada, with Old Vaquero (+33% faster fire rate with revolvers and lever action firearms)
 * Lily Bowen, when off the meds (Permanent stat bonuses, psychotic break at 50% health)
 * ED-E, after Brotherhood Examination (+8 DT) or Followers Examination (+5 DAM, +8 DPS, +0.5% Crit Chance and +15 Crit Damage)
 * Rex, when healed with Rey's brain (+25 damage) or Lupa's brain (+10 DT).

Weapons

 * With the exception of Rex and ED-E, all companions can be issued with better weapons. However, Lily Bowen and Dog/God are limited by their animation sets and will not be able to use most pistols and SMGs. They will use the best weapon in inventory (determined by their DPS, Damage Per Second rating) and must be provided with the appropriate ammunition.
 * While companions can be given modified weapons for use, the game ignores these modifications and will treat and render the companion as if they were using an unmodified weapon. The weapon will retain the modifications when removed from the character's inventory. Pre-modified unique weapons like the Ratslayer work as intended, this only applies to player-modified weapons.
 * Companions will use special ammunition types if they are placed in their inventory, but they will not switch ammunition types after running dry. This is fixed by simply giving them one type of ammunition per caliber.
 * If a weapon breaks, such as when it's shot out of their hands, companions will drop it to the ground.
 * Most companions have default weapons with infinite ammunition that have identical statistics to the weapons they are based on:

Armor

 * Companions can be issued better armor to wear, with the exception of super mutant followers (Lily and Dog/God), ED-E, and Rex, and they will automatically equip apparel with the highest Damage Threshold in their inventory (the sole exception is when they have multiple copies of the same item, when they may equip a more damaged one).
 * Companions can wear power armor by default.
 * Companions will not wear faction apparel and automatically drop it to the ground (this applies to companions who cannot wear armor too). The sole exceptions are Boone, who will wear any NCR faction armor, and Veronica, who will wear Brotherhood faction gear.

Behind the scenes

 * Several remaining resources point to the game having at one point allowed for the Courier 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.

Bugs

 * It's possible for the companion to become stuck and disappear from the world map and fail to appear when the player uses fast travel. It's possible to get them back by visiting a location where characters are moved by script, such as the Vault 22 elevator. Traveling to Level 5 (Pest Control) will usually spawn the follower there. In other cases of missing companions, consult the Talk page.
 * If placed at Lucky 38, companions' weapons may be switched around in rare instances.
 * If the player dismisses the companion either by returning to base or sending them to Lucky 38, the companion might not appear at the target location correctly in spite of the message displaying on the HUD. The player can fix this by going to the location where the companion was recruited.
 * In certain circumstances, it's possible to recruit multiple followers, such as sending Veronica, Raul, and Rex to the Lucky 38, then re-adding them in that same order.
 * If the companions were still trying to reach the player character's location when fast traveling, they might start running back towards the player character's previous location. Reloading or talking to the companion and telling them to Wait, then Follow again fixes this problem. This is particularly common in hilly areas with plenty of rocks, as companions may become stuck there.  In some circumstances, if the player exists their AI radius while they're stuck, they will switch to Wait mode.
 * This can also happen when the player enters an interior.
 * Due to the way the game's loading system works, Pip-Boy markers for companions will not disappear when starting a new game until the player restarts the game.
 * The Companion Wheel is not perfectly aligned, the active areas are off by 40 pixels relative to the graphics.


 * Be careful when entering an area populated with enemies because if you enter and your companions are too far away when you enter, they might be placed in the middle of a group of enemies and possibly die before you can get to them.
 * The option to dismiss companions to the Lucky 38 will disappear even before Mr. House becomes hostile to the player.
 * Items in companion inventories will sometimes disappear from the inventory, yet the weight of the item(s) will still remain.
 * With patch 1.3.0.444, fast-traveling or moving into rooms that need loading cause your companion(s) to walk away from you. Chasing after them and makes them continue to run away. If you can catch up to your companion(s), you can order them to Wait, then Follow and they will act normally. Another way they will stop walking away from you is when they encounter an obstacle like a wall, they will turn around and walk back to you and resume normal companion following. You can also try to render your companions unconscious. This bug isn't much of a problem within a building but outside where there maybe no obstacles to turn them around or trying to catch up with your companions and ordering them to Wait can be problematic, especially with ED-E and Rex who can run faster than you.
 * If you tell your companion to wait while the plane in Lake Mead is on the surface and then tell Loyal to take the plane, your companion will become stuck on the bottom of the lake, preventing you from telling them to follow you. This can be fixed by using the companion dismissal terminal outside Gunrunners.
 * The Companion Wheel's click areas are misaligned to the mouse (roughly 40 pixels below where they should be).
 * If the companions are regaining consciousness then shot to unconsciousness, they will be flung away or reset falling down.

Fixed bugs (Patch 1.2.0.31x)

 * Companions could start fighting each other seemingly at random at the Lucky 38. This was caused by the sandbox AI causing human companions to attack non-human companions, if the latter happened to carry any consumables.
 * Companion weapons confiscated at casinos were not always returned to them properly. Sometimes, the weapons were returned to the player's inventory, but were impossible to give back and use (as they run on the infinite Magical Companion Ammo).