Players will be able to expand their operations to include "Forward Operating Bases" which can be used to generate resources and income for the single-player campaign.[46] These facilities can be attacked by other players, making a player-versus-player mode available whereby the attacking team attempts to steal resources and the defending team tries to protect the Forward Operating Base from the intruder. Defenders will also be able to call on their friends to aid in the defence, especially if their Forward Operating Base is attacked during a story mission.[47] Players will be able to customise the security, staffing and layout of their Forward Operating Bases, allowing for an infinite number of compound configurations. Following the success or failure of the intrusion, the location of the attacking player's Forward Operating Base will be revealed to the defending player to allow for counter-attacks.[48] The Forward Operating Base feature is intended to be an entirely separate multiplayer experience to Metal Gear Online 3.[46]
From wikipedia.
