Fallout 3 companions

Permanent companions
There are 8 permanent companions available to the player in Fallout 3. All companions except for Dogmeat and Charon have a Karma requirement that must be met if the player wishes to enlist that companion (listed in parentheses).

Pictured, left to right:
 * Star Paladin Cross: Brotherhood Paladin (Good)
 * Butch DeLoria: Tunnel Snake (Neutral)
 * Clover: Paradise Falls slave (Evil)
 * Sergeant RL-3: Mister Gutsy robot (Neutral)
 * Jericho: Retired raider (Evil)
 * Fawkes: Super mutant (Good)
 * Dogmeat: Dog (no Karma requirement)
 * Charon: Ghoul bodyguard (no Karma requirement)

If the player character ever tells a companion to wait but forgets where they did this, they should travel to any add-on location. This will send the companion home. Sometimes this does not work with the add-on Point Lookout.

The player character can have up to two companions in their party, which consists of Dogmeat plus any other companion, barring certain companion exploits.

XP
Unlike in previous Fallout games, companions don't gain experience and notoriety independently but are scaled to the level of the player character.

The player character earns full XP if able to deal at least 30% of the damage necessary to kill an opponent, otherwise, an enemy killed with the help of followers earns zero XP. Delivering the killing blow oneself is neither necessary nor replaces the minimum damage requirement.

Combat
Companions come with their default weapons and armor and will use these, depending on what role you ask them to play (melee or ranged). They will also wear any weapons or armor they are given that is superior to their standard equipment. All human and ghoul non-player characters (so all except Fawkes, RL-3, and Dogmeat) are capable of wearing power armor. Armor and weapons worn by companions never degrade with use.

Companions have unlimited ammunition for their standard weapon (with the exception of Butch), but you'll have to supply them with the appropriate ammunition for any other non-default ranged weapon.

If a companion is given several weapons and the appropriate ammunition, they will generally choose a weapon based on the range of the projectile, then on either damage per round (DPR) or damage per second (DPS) but not by the in-game interface's DMG stat. For example, if you equip Star Paladin Cross with a flamer, she will first attack with her default laser pistol because her target is out of the flamer's range. She will move towards the target to get into the flamer's range and then switch to it. There are exceptions, however. For example, Charon will always use Protectron's Gaze (a unique laser pistol) over the laser rifle, despite its reduced range AND damage per round rating.

Some companions will use any weapon if you give it to them (provided they have appropriate ammunition for it). There are some exceptions, such as companions cannot use the Gauss rifle rewarded upon completion of the Operation: Anchorage add-on, but can utilize the sim-only version obtainable through glitching or console.

Companions have significantly more health than other non-player characters.

Enemies are able to shoot your companion's weapons out of his or her hands (except their default weapons), so take care if you give them any unique weapon.

Companions are restored to full health at the end of combat after all nearby enemies are dead. However, if you zone out during a fight and they follow while injured, or if they are injured outside of combat (e.g. a booby-trap), they do not heal (until after the next combat). They can also use stimpaks in their inventory in the middle of battle if you gave some to them earlier. Dogmeat can't carry stimpaks, but you can speak to him in the middle of combat to heal him manually. You can check companions' health by viewing them in V.A.T.S. mode, or moving far enough from them to see their HP bar. Companions are not considered "essential" non-player characters, so they will die if their health is fully depleted. There is no way of reviving them unless using the 'resurrect' command via console, targeted on their corpse.

Some companions will enter sneak mode when you enter sneak mode, and end it when you do. They may also randomly enter sneak mode during combat, presumably to avoid enemy fire or to gain better aiming.

Statistics

 * Companions can be used to store items, allowing the player to collect more items before becoming overencumbered.
 * For a detailed list of the companions' equipment, see Fallout 3 companion equipment.
 * Carrying capacity will be, e.g., 50 pounds less if given power armor (45 for armor, 5 for helmet). Capacity is determined by: (Base of 150) + (10 * Strength) - (Weight of inherent gear) - (Weight of anything else, including replacement armor or weapons)

Firing permanent companions
In most cases, companions can be dismissed/fired, and can later be found and rehired. In most cases, when fired they always travel to a specific spot, usually not the same spot they were hired. In some cases, they can always be rehired by simply finding them and asking them to rejoin you. Also in some cases, there will be Karma or other requirements. For example:
 * Butch: The Muddy Rudder in Rivet City. Can be rehired any time, but only if Karma is Neutral.
 * Charon: If fired, he will return to The Ninth Circle. He can be rehired anytime regardless of Karma.
 * Clover: If fired, she will return to Eulogy's Pad in Paradise Falls (even if the player has killed Eulogy Jones and abolished slavery by wiping out everyone in Paradise Falls). She can be rehired regardless of Karma.
 * Dogmeat: Isn't really "fired," he waits by Vault 101 as ordered.
 * Fawkes: If fired, Fawkes will travel to the Museum of History where he will wait for you just inside the front door. You can rehire him any time so long as your Karma is good. No charge or other requirements to rehire him.
 * Jericho: If fired, returns to Megaton, he is found inside Moriarty's Saloon, unless you have blown up Megaton, then he just waits at the ruins. You must have evil Karma to re-hire him.
 * Sgt. RL-3: If fired, will travel to the entrance to Canterbury Commons (at the traveling merchants' stop near the trees), where he can be rehired with neutral Karma.
 * Cross: If fired, she will return to the Citadel laboratory, where she can be rehired if your Karma is good.

Temporary companions
Temporary companions are companions that will join you during a quest. Most of them will follow you indefinitely until you complete their related quest, but not all. Unlike permanent companions, they do not heal automatically at the end of a battle but must be given stimpaks through reverse pickpocketing or healed through dialogue (still requiring a stimpak from your inventory). Most of them can use weapons and armors. And because they are non-player characters, they can use weapons forever with only one bullet. There are some hostile non-player characters that could become friendly to the player and permanent companions, but they will still attack temporary companions, like Arkansas or the protectrons in the RobCo facility. The traps or mines of allies, like the frag mines laid by the citizens of Big Town, will still be hostile to temporary companions.


 * Initiate Pek
 * Bumble
 * Cherry
 * Shorty
 * Rory Maclaren
 * Doctor Li (only during The Waters of Life)
 * Red
 * Sarah Lyons (only during Take it Back!)
 * Sticky
 * Sydney
 * Paladin Hoss

Of the listed temporary companions, only Red, Shorty, and Sticky have dialogue options which allow the player to give them weapons or other inventory items.

James is scripted as though he were a permanent companion; for example, he uses up ammunition on playable weapons, something only permanent companions do. However, his package is "escort" instead of "follow", so he can't be taken places like a normal companion can be.

Operation: Anchorage only

 * Sgt. Montgomery
 * Strike Team grenadier
 * Strike Team infantryman
 * Strike Team missile unit
 * Strike Team Mister Gutsy
 * Strike Team sentry bot
 * Strike Team sniper

Broken Steel only

 * Paladin Tristan (only during Death From Above)
 * Brotherhood of Steel Paladins and Knights (when inside the Enclave building trying to find the encrypted codes, and during Death From Above)

Point Lookout only

 * Desmond Lockheart (only during A Meeting of the Minds)

Mothership Zeta only

 * Paulson
 * Elliott Tercorien
 * Somah
 * Toshiro Kago
 * Sally