Mother Base is your base of operations and safe haven away from the dangers of the fields of battle. You will unlock it very early in the game, with a majority of its functions being available then. The biggest draws of the Mother Base are being able to build it up using the very same enemies you fight, which can be done by using the Fulton extraction device given to you.
The only catch is that dead enemies don’t make good workers and if you injure them enough, you won’t be able to Fulton extract them either. That’s where the default tranquilizer pistol comes in, as well as CQC, since both of these preserve the enemy so that can be extracted back to Mother Base and begin working for you.
Each of the personnel you extract will have stats attached to them, which are hidden until you get an upgrade for your binoculars. These stats will determine which unit that person will be placed in, with each unit having a special function within the game. Each unit can be leveled up as more personnel are placed in it, unlocking new functions. For example, Research & Development (R&D) will enable more items and weapons to be developed, while Base Development will secure more resources.
Development and Base Facilities
Each of the units have their own platforms at Mother Base, with there only being one once they’re unlocked. In order to unlock more, you will require resources that can be used to build more platforms for each unit, allowing you to place more personnel in them. It’s important to continually search for resources in the field so you can build up the platforms to allow more people to join Mother Base.
Resources are also used to fund the development of new items and weapons. These weapons and items, though, have requirements in the form of specific unit levels, as well as some certain items, like Blueprints or Key Items. You can move personnel around to achieve a greater level for a new item/weapon, develop it and then switch them back to their original unit, if you like.