There are many reasons to play with others in Babylon's Fall including sharing the experience and eliminating the need for constant grinding in a solo playthrough. Unfortunately, Babylon's Fall doesn't have a traditional invite system, and the process for joining a friend or having them join the player's game is a bit unclear at first. However, to reach the point where others can join, players will need to get their Gideon Coffin in Babylon's Fall and complete the opening sequence of the game.
Before playing with others, players will need to get through the beginning of the story in Babylon's Fall and make it to the Sentinel Force HQ, which acts as a central HUB. The Sentinel Force HQ is the base of the tower where players can change their gear, purchase new items at the shop, interact with NPCs, and connect with other players. Friends need to join while players are in the Sentinel Force HQ, because they won't be able to join once a quest is started.
Related: Rainbow Six Extraction: How To Play With Friends Using The Buddy Pass
After choosing a faction and creating their Sentinel, players will watch the opening cutscenes and complete the tutorial, then have the ability to start playing with friends. Once players get started in Babylon's Fall and reach the Sentinel Force HQ, they'll be able to join other HQs or have friends come to theirs from the in-game menu. However, Babylon's Fall doesn't have a traditional invite system, so players will need to be at the same HQ as the people they want to play with.
From the Sentinel Force HQ, players can pause the game and tab over to the Community menu. In this section, there's an option to access the player's Friend List. A friend can be added by searching for a username and
Read more on screenrant.com