Obtaining an FOB
Of course, before you can do anything with an FOB in Metal Gear Solid V: The Phantom Pain, you must first obtain one. To do so, you must complete Mission 22 ‘Retake the Platform.’ This will grant you the ability to build your very own FOB (the first one is free). Players will have the ability to build up to four, but note that the other three will cost you MB coins.
MB coins are a currency that can be bought with real world money or obtained in game through methods such as the daily reward just for logging in, although you don’t get too many for that. You can also pay MB coins to move your free FOB, but it honestly isn’t worth it due to the price, so just stick with what you pick and then build your next one where you want.
One thing to keep in mind is that if you don’t want certain soldiers being shipped out to your FOB after building one, make sure to put those soldiers under Direct Contract in your Mother Base tab on your iDroid. This will lock that individual into whatever platform you have him/her assigned to.