Update: Thanks to Xbox Cloud Gaming you can Halo Infinite multiplayer on both generations of Xbox, as well as smartphones, via streaming on the Xbox Game Pass app.
Halo Infinite's multiplayer is now live for everyone, not just Xbox Live Gold and Xbox Game Pass subscribers, on Xbox One, Xbox Series X, Xbox Series S and PC. This means that you and your buddies can jump into some sci-fi shooting shenanigans right away.
Below, we've also added steps on how to install Halo Infinite's multiplayer mode.
How to install Halo Infinite multiplayer on Xbox Series X
These instructions apply to the Xbox Series S as well.
First, go to the Store and search for "Halo Infinite"
It should bring up two options. The Halo Infinite singe player and multiplayer campaigns. Click on Multiplayer.
On the Compare Editions screen, click on Multiplayer again.
On the next screen, click Install. Once clicked, you can see the progress in your downloads queue. The initial download should be 280.23 MB as of this writing. Clearly this is incorrect, as there's no way the base game and multiplayer are this small.
Given that today marks the launch of the game, there may be issues for people who are trying to jump in. We got a blank blue screen when we tried to load the game. Who knows how long it will take for Microsoft to sort this all out?
How to install Halo Infinite multiplayer on PC
Load up a Windows 10 or Windows 11 PC.
Click on Start and click on the Store app.
In the search bar type in "Halo Infinite" and click on the Halo Infinite (Campaign) icon.
In the Halo Infinite (Campaign) menu, scroll down to the In this bundle section.
This should take you to a different menu dedicated to the Halo Infinite Multiplayer Season 1 campaign. Here, click on Install from Xbox app.
This will open the Xbox App where you can click Install and download the Halo Infinite Multiplayer.
Tip: Click on the three dots to also install the high resolution texture pack if you're playing on a high-resolution monitor. As of publishing, this download is 26.4GB in size.