Buy Assassin's Creed 4 Black Flag - Season Pass

If you do not have a Steam account, you will need to download the client from the official website, install it and then create your account. Once you are logged into your account, click on "Add game" in the bottom left corner and then on "Activate product on Steam". After a few clicks on "Next", you can finally enter your CD key, the game will automatically be added to your library and the download will begin.

More information on Steam

To install your game via Ubisoft Connect, you must first download and install the client from the official website. Then open the software on your computer and log in to your Ubisoft Connect account. Click on "Activate Product" in the drop-down menu at the top left of the screen and enter the product key exactly as it was provided to you. If your key is valid, the game will be added to your Ubisoft Connect game library. You can then download and install the game.

Learn more about Ubisoft Connect

Use your Microsoft Points game card on Xbox Live Marketplace on your Xbox Series X, Xbox One or Xbox 360 to buy full games, rent the latest movies in high definition and enhance your games with downloadable content. Unlock the full potential of Xbox Live! To access Xbox Live Marketplace, you will need the following components and services: an Xbox Series X, Xbox One or Xbox 360 console, a broadband internet connection, an Xbox Live Silver membership (included in Xbox entertainment content), a Microsoft account and an Xbox console hard drive or storage unit.

Use your code on the Xbox Live network to activate your games or increase your Xbox Live account's credit. To access the Xbox Live network, you need the Xbox One, a broadband connexion, a Xbox Live account, and a storage device according to your console: Hard disk drive, memory card, or USB drive.