The Forza Horizon series has always been about fusing realistic driving mechanics with the freedom and quirks of exploring open environments. One of the biggest changes coming to the franchise with Forza Horizon 4 is that its open world will be populated with actual players, in hopes of making it feel more lived in--hence the ‘shared world’ designation. So long as you're online, real players will be cruising around the world at all times instead of drivatars (AI cars simulating real player behavior) seen in past entries. But the goal isn't just to fill the game with actual people going about their business, the shared world also functions to induce new multiplayer experiences.

Entering races alone or as a group (or Convoy, as the game calls it) is said to work seamlessly as you're temporarily put into a parallel server outside the shared world, and immediately put back in afterward. There's also hourly events called Forzathon Live where anyone can jump in for cooperative challenges to earn rewards. This doesn't mean that you're required to be online to play the game, though. Forza Horizon 4's campaign can be played entirely solo and will include drivatars to fill in the gaps.

Forza Horizon 4 4K Xbox One Gameplay | E3 2018

We spoke with the creative director Ralph Fulton and principal designer Mike Brown from developer Playground Studios to get a more detailed explanation of how Forza Horizon 4's shared world operates and how it mixes up the series formula. Note that the following interview has been editorialized for clarity and readability.

Forza Horizon 4 is the 11th entry in the long-running racing franchise, and the standard and deluxe editions launch on October 2nd while the ultimate edition lands on September 28 for Xbox One and PC. There will be cross-play between the two platforms and it'll also be available through Xbox Game Pass on launch day. Be sure to read our Forza Horizon 3 review and Forza Motorsport 7 review to see the past few games have fared.

GameSpot: To kick it off, could you explain how the shared world is different from past Forza Horizon games?

Ralph Fulton: To frame how we got to where we are now you're going to need to look back at the history of [Forza] Horizon. We have four pillars in the Horizon series that we constantly refer back to when we are making a new game. We talk about fun, freedom, beauty, and community being our fourth pillar. And obviously with every game we're trying to up the limit in each of those areas, but I think community has probably been the area where we've found the most headroom. And we've been really start pushing to give our fans and our players new ways to interact with each other. That just seems to be the thing that they enjoy doing, that they really value in Horizon games because they’re just really social by nature.

Different vehicles are at your disposal in Forza Horizon 4, from exotic supercars and rally cars to motorbikes and all-terrain trucks.

So, in Horizon 2, we brought in seamless multiplayer and player clubs. In Horizon 3, we brought in co-op for the first time. We've made this huge step forward with Forza Horizon 4, now where everyone will play in a shared world. So, it's not really about single-player or multiplayer anymore so much as everybody just doing what they want in a world that's populated with other real players doing whatever they want to do at that given moment.

GS: To be in the shared world, you have to be connected online all the time. But what does it mean for someone who only plays offline in single-player by themselves?

Mike Brown: That was something we discussed a lot right at the start of the project on Forza Horizon 4. We wanted to make it a shared-world game because we know that there are countless benefits to that. It's also has much richer community interactions. It brings with it loads of immersive gameplay.You have all this vibrancy of other people in your world doing stuff that you might never expect to see or you might never otherwise see.

But equally, we're not deaf to the fact that there are a lot of players out there who just don't want to play with other people, or who can't play with other people for reasons out of their control. Servers may go down or any multitude of other reasons. So for that reason, as much as we call it a shared world game for type before is totally playable offline.

You can play through the entire thing, the entire campaign, offline, without internet connection, if that's how you want to play. And you can click a button and you'll drop into an offline world and then your open world is populated with driver files, similarly if you're playing and your internet goes down or something to that effect. The game will simply transition to a solo world where those real life people you were playing with will be replaced with drivatars, and you just carry on as you were. It doesn't drop you out to the main menu or anything, any of the nasty scenarios like that. It just keeps you playing and having fun.

GS: Would you say Forza Horizon 4 shares similarities with how MMORPGs function where you have this big world where players can connect and group up or do their own missions simultaneously?

MB: Sure, yeah you're connected just driving around the world, you'll see people zooming around, going about their own business. Anybody you meet, you can drive up to them, connect and invite them to join you on what we call a Convoy, which is just a persistent group that exists for up to 12 players—then you can play together. And you have a Convoy leader who chooses tasks for that group to do.

As I've mentioned, we introduced co-op in Forza Horizon 3. And now the entire game [Horizon 4], you can just go meet a person in the open world—maybe you're both drifting around the same area of Edinburgh—and say, "hey, wanna come and join my Convoy?" Now they're in a little mini party. You're still in the open world, you'll still see other people buzzing around, but you two are in an assisted group, so you can go and do races or Horizon Stories, which is a new gameplay feature. You'll basically play together for how much you want to play together.

So yeah, it is kind of MMO-ish, although in the sense that there is a shared world in which you team up with people and take part in activities together. It doesn't have any of that sort of rules of MMO systems.

RF: And what we think is the real value in this shared world isn't so much, "hey, everybody, play together", we're not trying to force anyone into doing something that doesn't come naturally to them. We think the value is, like Mike said, this world becomes much richer, so much more interesting and spontaneous through the presence of real people doing real people things. In Horizon 3, our world was populated with drivatars, that does a pretty decent job of approximating how real players drive. But honestly, it can never come close to the variety and the unpredictability that real people have. You can't program that kind of variety. And I think that's going to be the real joy for players. Not necessarily going and playing with other people, just seeing other people going about their games.

GS: In Horizon 3, when you're almost in contact with drivatars, they would ghost so they don't get in your way. How are you handling collisions now that there all these people in a shared world?

RF: It probably falls into the category of questions that we asked ourselves a lot at the start of this project. Almost kind of troubleshooting shared worlds before we set about making our own. One of the first things you run up against when you start talking about shared worlds, that everybody lives together and, "alright, there's gonna be some asshole that crashes into me, spoils my game," and we felt that we had to find a solution for that.

The way we solved it is that, by default, other players in your world won't collide with you, they'll just ghost right through you. They'll still appear solid, so you can still get that cool sensation of admiring their car, as they drive past you, or their parked up. But they can't come and deliberately, or even inadvertently, spoil your game by driving into you.

It changes by teaming up with somebody, going into a Convoy together. By default, when you're in a Convoy, you suddenly have collisions with the other people within your Convoy. You have that sort of physicality, you can drive and into each other and collide. There's a ton of people in there who actually get a kick out of that, crashing cars into each other. It's kind of a fun thing to do. We allow that in the context of a Convoy where, again, everybody has signed up for that.

GS: For example, if I jump into a circuit race in the world, does that take me then to a separate realm? Will I also see drivers within the world who are doing circuit races or just driving about?

MB: It depends on which options you choose. When you go into any race in the game, they can all be played solo, where it's just you against AI drivatars. You can play co-op, where it's you and a team of other human players, against a team of AI drivatars. Or it's PvP, where you can play against a whole field made from groups of human players.

If you do choose solo, then at that point you'll silently kind of pull out of the online server, do your race, and then you're brought back there [to the shared world]. You can play with the entire campaign, with every race being a PvP race, if you wanted to. If you're against, other real people, then again, you'd be in a kind of parallel realm whilst you do your race, and then you'd go back into the shared world. You won't ever have a random person who wasn't involved in race, driving across while you're in there.

GS: Will there be any exclusive events or specific features for those who do interact with actual people within the world? Maybe, special quests or races that revolve around grouping up?

RF: Obviously, it's up to you how you play, but we think the game is more fun, more rewarding when you play with others. We have exactly that kind of system, which is called Forzathon Live, which is designed to do just that. It's a kind of public event that happens every hour, on the hour somewhere within the game world. It's pretty well advertised when it's happening. There's a big blimp that floats above the start point that everyone congregate around to join up.

What happens after that is basically a sequence of challenges and events in which all of the participants in the shared world who opt into Forzathon Live, will go do cooperatively. Basically, that group that signed up at the start of Forzathon Live, their score will be accumulative across the whole group. And if you meet certain thresholds, you'll earn certain awards for the whole group.

So, it's very much a collaborative thing. All the players will work together and share their awards that they collect and win. The last 15 minutes of it changes, so you can spend that time doing Forzathon Live with different players. And there's some cool rewards for that, as well as the fun of jumping in very frictionlessly playing with others in a collaborative non-adversarial way. That whole thing, collectively succeeding and then sharing the rewards with everyone.