So ok, assuming I have Xbox One X with my account that it used by third party to play GamePass games and I have my XSS with my own account I use. What should I do on Xbox One X to allow another person to play GamePass games in Co-op with me?
What about guest accounts?
This is going to be long winded but its important to understand how this works.
When you buy a game digitally, or subscribe to game pass, the account that has made the purchase is given two licenses to that content.
One license is tied to the console that is registered to that person. (Your home xbox) and another is tied to the account of whoever purchases it. This is how when you go to a different box and sign in you are able to play all your content as long as you are signed in. This is also why you anyone else can play games on your console without you being signed in, as long as that console is registered as your home console.
If you wanted to share the content with another box you need to take whatever account that has the license to use the content and sign in onto the other box. Naviagte to the settings and find the My home Xbox Setting.
WHen you change your home xbox account to this new xbox, this box will now have the ability to use all of the content associated with that account. Which means if you bought a copy of Gears Tactics, anybody on the new box you registered can play it.
On your original box that first was registered, you can still play Gears Tactics as you,
but you have to stay signed in with your account at all times since the license that would work on a console level has now been moved to the other box. This work on Game Pass as well.
Also note you can only change your home Xbox I believe 4 times a year.