Permanent companions require a few requisites to be met in order for them to join the player's party. For a few non-player characters, there is more than one possible way to have them join your party. There is a maximum number of companions one may have. Take the player character's Charisma stat and divide it by two. This calculates the Chosen One's number. Example: 4 Charisma is 2 companions. With the perkMagnetic Personality the Chosen One gains one more allowable companion.
Once a non-player character becomes the player's companion, their dialogue menu changes to a list of tactical and combat-oriented options. New from Fallout is a "Combat Control" button in dialogue, which lets you manually change an non-player character's armor, weapon, distance, and tactics.
The picture to the right is the in-game dialogue box for controlling companions. For permanent companions, the options are shown as follows:
Use Best Weapon
At first, this doesn't do anything, because the companions originally only carry their default weapon. However, the player may so gift them with a better weapon (and ammunition, for guns), then the non-player character will make use of that weapon instead. Alternatively, the companion can pick up weapons found on the ground.
Use Best Armor
This control acts the same as the one above; give the companion a better suit of armor, and they will equip it in place of their default armor, granting them the corresponding bonus to Armor Class.
Berserk - The companion will always attack, never fleeing from battle, no matter the level their health drops to.
Aggressive - The companion will attack while their health is in an acceptably decent range. If it falls too low, they will ultimately flee from combat.
Defensive - The companion will be more mindful of their health, running when they are injured, even if just slightly.
Coward - The companion will always run from a battle they think they cannot handle, regardless of the opponents.
Custom - There are six options with 5 sub-options that can be chosen by the player concerning the non-player character's disposition. The possible options for each is listed below.