By Luke Reilly

For the first time in the series Forza Horizon 4 is a shared world game. It’s a big change, and one which Playground Games creative director Ralph Fulton describes as a “huge paradigm shift.” It’s also a potentially a concerning one for some but, as it’s still optional, it probably shouldn’t be.

First and foremost, the nature of Forza Horizon 4’s shared world changes the other racers you’ll see while cruising around the open world. In Forza Horizon 2 and 3, the cars you saw hooning around the environment were what the Forza series dubs Drivatars; AI powered driver profiles drawn from your friends list and beyond. In Forza Horizon 4 we’ll still race against Drivatars when we start an event, but the cars you’ll encounter in free roam will now be real people within a 72-player server. The reason Playground Games is doing this is because the team believes that real players will exhibit more interesting, more unpredictable, and more fun behaviour than they could ever program into Drivatars.

To pump up the amount of players online in the world at any one time (which in Forza Horizon 3 topped out at 12), Playground Games has stacked a bunch of 12-player universes on top of each other, all controlled by a 72-player server. Forza Horizon 4 will group players together in universes of 12 roughly based on the area they can see in the world. Essentially, when two people come near each other, they’ll go into a universe together. There’s no loading, of course; it’s all happening below the surface. So now, as you’re traveling around the 72-player world, you’ll move seamlessly from universe to universe seeing the nearest people come and go as you drive.

Again, playing in the shared world isn’t compulsory. Forza Horizon 4 isn’t an always online game, and you don’t have to play in the shared world if you don’t want to. You can opt out with the push of a button and seamlessly transition into an offline experience that will replace the real people with Drivatars again. According to Playground, this will ultimately be similar to the solo, open world free roaming experience of Forza Horizon 3.

But if you are up for it, check out the video at the top of the page as we use two tins of beer and 72 Matchbox cars to explain how Playground Games has brought Forza Horizon 4’s shared world to life.

You can reach all of this month’s IGN First content on Forza Horizon 4 from this hub, including our behind-the-scenes report from our visit to Playground Games in the lead up to E3 2018, our video deep dive on why seasons change everything in Forza Horizon 4, and our in-depth look at the insane new McLaren Senna.

Luke is Games Editor at IGN’s Sydney office. You can find him on Twitter every few days @MrLukeReilly.