Companions are a gameplay mechanic that allows the player to recruit and travel with specific characters. Certain companions will have requirements that must be met in order to join the player.
Companions cannot be controlled directly. Instead, one can change some settings for their AI. The protagonist levels up but their companions do not.
Permanent companions usually have prerequisites and may not join your party unless certain conditions are met. Each companion has a fixed number of predefined levels called "stages" in the form of multiple alternative models for them with different statistics. Each time the player character gains a level, every current companion has a chance to go up a stage.
In Fallout Tactics, companions are referred to as recruits. These characters may only join the party if the player can afford the recruitment cost.
Fallout: Brotherhood of Steel
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. The player character can have up to two companions in their party, which consists of Dogmeat plus any other companion.
Fallout: New Vegas
It is possible to have up to two 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, giving them new armor or new perks. Temporary followers are NPCs that can accompany the player character during quests, for a limited time, or within a certain area.
The base game offers 13 unique permanent companions, each with their own personalities and storylines. Automatron adds two new, fully-customizable robot companions. Both Far Harbor and Nuka-World introduce a single companion. The total number of companions is 17.
Players are encouraged to form Public Teams and band together against the threats facing Appalachia and beyond. Several perk cards are designed with multiplayer in mind and provide effects similar to the companion perks in previous games.
Certain characters may serve as temporary quest companions that aid the player during select quests. These temporary companions will not revive players that are down in combat but may be revived themselves should they run out of health. If they are not revived, they will heal themselves and return to action after a brief moment.
Fallout 76 includes characters that may be recruited to live at player C.A.M.P.s. These Allies will not follow the player around, but they can offer a variety of services ranging from temporary bonuses to entire questlines. Allies will only appear once their associated workshop object has been placed. Although only one Ally may be active at a time, there are workshop objects that will spawn a friendly character.
- Collectron stations will generate items over time and spawn a Collectron robot to defend the C.A.M.P. from hostiles. Their harvesting routine may be changed at the attached Collectron station terminal. Only one Collectron may be placed at any given time but new harvest options may become available by unlocking additional Collectrons.
- The Brahmin pen will generate raw fertilizer over time and spawn a Brahmin that will ignore combat.
- Workshop turrets, mannequins, and even the chassis display frames are all technically non-player characters.
- A friendly Vertibot may be called upon to help anywhere in Appalachia by throwing a Vertibot signal grenade. This will not work if the player does not currently control a workshop with a functional Vertibot.
In addition to the above, players with the Animal Friend perk may discover docile, tameable creatures during certain random encounters. By walking up to the creature or aiming, a button prompt will appear that offers the option to tame the creature. Accepting it will cause the creature to walk directly to the currently activated C.A.M.P. where it will serve as a guard dog.