Back 4 Blood is a game that you will want to have your most trusted friends by your side on. People that you can trust to save your back when you get into trouble and carry enough of the shooting power, so you are not being overrun by Ridden. Here is how to add your cross-platform friends in Back 4 Blood.
How to add cross platform friends
When you start up Back 4 Blood for the first time, you will have a box asking you to claim the username you will use for the game. If you bring up the menu, you can see what it is anytime while in the Fort Hope hub.
To add a friend, bring up Social and press Add Friends. Now you need to get your friend to tell you their account name. Put it in just like how they have it and press Search. You will see a list of accounts with that name and what platform they are on. Unfortunately, as of this writing, there is no confirmation of cross progression support, so you may see some very similar names if your friend plays with a similar name on multiple platforms. Select the one you want and send the request.
How to accept cross platform friends request
To accept a request, go to Social, and you can pull up the Friend Request tab. Add them, and you can party up and begin playing.