As a growing game as a service model, Marvel's Avengers is a game that requires constant online connection to get the most out of the title. While playable solo, the game's missions are best experienced with other people, which can only be done after linking a Square Enix account. Here's how you can tie it up and enjoy all that Marvel's Avengers has to offer.
To start linking your Square Enix account to Marvel's Avengers, first go to sqex.me/link in a browser on your phone or computer. Once there, log in or create a new Square Enix account. If you want, you can use your Facebook, Steam, or Final Fantasy XI or XIV online account to quickly login. Once logged in, you will need to enter a nine-digit code which you can find in the game itself.
To find the code, start the game and choose Campaign or Avengers Initiative to load in a session. If you've never received a prompt that says you've linked your Square Enix account to your profile, a message should appear to guide you through the steps. Otherwise, you can go to settings and switch to Legal. The bottom option will allow you to view your Square Enix subscription. If you have already logged in your account, a message will appear stating that you are good to go. Otherwise, you will receive the code to enter on the site. After entering it, the game should recognize the connection.
Once your Square Enix account is connected to your Marvel's Avengers game, you will be able to play the game cooperatively with other players online. It also entitles you to future game updates, including new missions, heroes, and story expansions that will be free once released.
If you're having trouble with your subscription connection, you can go to your account page on the Square Enix website. Scroll down and you can manage your associated accounts. Here you can see which accounts your Square Enix subscription is connected to.
If you do not see the platform on which you are playing the game connected, click on the paperclip icon on the right and follow the connection process presented to you.