During Bethesda's E3 showcase last week Avalanche's Magnus Nedfors and id Software's Tim Willits stepped up to confirm some surprising news: the two developers, united by Bethesda's reach, were working together on a followup to id's 2011 post-apocalyptic shooter Rage.

It was a bit of a surprise given how long the Rage franchise has laid fallow, and how different the games of Avalanche (Just Cause, Mad Max​, theHunter) and id (Doom, Quake Champions) appear to be.

But when Gamasutra sat down with Rage 2 game director Nedfors to talk about how the partnership came to be, he made a point of highlighting how the two studios are collaborating to share expertise and shore up each others' weak points.

In that interview (reprinted below in edited form) Nedfors shed some light on how Avalanche works with id, what the studio has learned about designing interesting open-world games, and why the studio places such a premium on systems-driven, physics-rich game design.

It's surprising to see Avalanche working together with id, and even more surprising that it's a followup to Rage. How did this project come about?

Nedfors: Avalanche and Bethesda in the beginning had been talking for a long while, we being an independent developer and them a publisher. So course we talked.

During those talks they said "hey, I think we have a great game and a great idea with a studio that loves action in the same way that you do," and that was id Software. They had a slot open and we had a slot open in our production lines and they presented the idea to us and we came with a pitch to them of what we wanted to do. Everything just melded together in a great way from day one. That's kind of the simplistic way of how it came about.

What's it been like then collaborating with id? Is it 50/50?

It's hard to say with development, but the game is developed in Stockholm by Avalanche. We have a very close collaboration with the id guys. Me and Tim [Willits, id studio director] for example, we talk to each other almost every day. We have weekly calls with a large group of management people and so on.

Also, especially in the beginning when we started to do the first-person shooting style, we had a lot of support from those guys. Like in how we think about deaths, don't do this mistake, etc. They have been part of the creative development of both the shooting part of it and also the game as a whole, the whole time. But the actual code and the art and so on, all the components, is mostly done by Avalanche and id has more of the supporting role. It's a super important supporting role in the way we developed it.

What are some of the things that you want to carry over from the first game, design-wise, and what are some things that you're like, "we can improve or cut those"?

Well, the weaknesses...as I pointed out already, I know the team says this a lot, but the open-world aspect, we want to expand that a lot. They had intentions, but maybe didn't go all the way in the first game. And they wanted to have a better ending to the story. Everybody felt like it was a little bit of a rough ending.

But if you look at the game as a whole, there were a lot of good things. I personally loved it a lot. Obviously the id style of shooting, but also the world and the setting; the characters were super interesting. They were really exaggerated in a nice way.

Just the whole world and the setting of the world -- the background and what's going on in that world and so on -- we wanted to keep that. Car combat was impressive in the first game, we wanted to keep that. So all of those elements and adding our open-world magic to that, combining and melding that together.

Let's talk about that open world. What are some key design pillars that you try to achieve, whether it's in Just Cause or in Rage?

Well, Avalanche kind of builds open worlds. That's what we love to do, everybody working there wants to do that. Apex, the game engine that we have developed, is built for that. So it's our specialty and that's what we like to do, it's what we like to play.

We have a few key things that we always want to achieve, like "no invisible barriers," like a sea or something like that, that say "no you can't go any further than this." In an open world when you see a hill over there and I see a tower over there, whatever I see I should be able to go there. And when I come there I should be able to interact with it.

The world needs to react to your actions. Reaction off the world is super important as well; we love dynamic content and emergent gameplay. We love to provide tools for the player to play with the world and the player to be creative and try different solutions. Some of the best times I have are when I see other people playing our games and I have a moment of discovery like, "wow, can you do that?" That's super fun because we just provide the toys and people are creative and they create whatever they want to do.

What's your approach to making those toys and tools for players?

Systematically? It's like, how does this affect things in the world, but don't plan it so I have to do it in a certain way. It needs to be a system, so to speak.

It's hard to explain what that means, but it's physically-based gameplay. Things have shapes and forms and weight to them like in the real world so if I interact with something in some way, it has properties that react to everything else.

There's a super nice story in one of our games where one of our team members, he came home and he saw some kids playing our game and the tire stuff, the air in the tires is part of the physics system, so they throw the car out on the water and try to drive the car over the water. And can you do that? Well, apparently you can. That's the physical systems working together like the water and the buoyancy of the car work together. Of course it sunk eventually but they could actually come to the water and compete and see how far they could go.

Yeah, there's some interesting physical stuff to the combat.

Of course you have all the heavy weapons feel from the id-style combat, but we also wanted that and a new flavor of that, so we have what we call nanotrite abilities. That's like different forces that you can use in the world. So for example, we have the Shatter as we call it that pushes things around, and you have a thing that changes how gravity works and so on.

So it's like toys that were made to play with, and they kind of complete the gameplay loop, so the player has guns but they also have these powers they can use to change the world around them. And also interacting with the world with those powers will give different responses and the world will react back to you.

There's got to be a lot of inspiration and lessons learned from the Just Cause series. How much crossover is there between the teams and things like that?

As a studio you get more and more experience with every game you do. It's true for us, it's true for id. We've all made a bunch of games in different areas and we take the knowledge of everything that everybody carries with them.

Of course internally in Avalanche we have people that worked on -- me for example I worked on every game in Avalanche since Just Cause 1 so I have all that experience. I've been partially part of the hunting game too [theHunter] so I draw knowledge from them as well.

I draw knowledge and experience from all the games that we do. It's not like let's take that feature from that game it's more about "yeah we did it like that." You learn and you grow as a company and a person and everybody grows and learns how to push things further ahead. It's not only Just Cause, it's all our games contributing to how we make our next game.

I'd be remiss if I didn't bring up the art direction on Rage 2. How did that evolve? Because Rage is notably brown and grim.

Again, both companies made brown games -- we made Mad Max as well and that's very brown. We love brown, but we felt like it was time to push the colors in the game for several reasons. [One reason was] to create a little more variation in the environments that you are in -- and that required a certain type of art direction, pushing these crazy colors, with pink and yellows.

Actually we looked back to the original -- maybe not the original -- but the comic books of the '80s and '90s. They had post-apocalyptic worlds and they were quite colorful. So we wanted to bring that feeling back, to create something new, to create a new feeling to it.

There are a lot of post-apocalyptic games. What do you think the appeal is with the whole apocalyptic, dystopia thing? People still have an interest in it.

Yeah people do. That's almost a philosophical question. I would think it's a situation that we can imagine ourselves being in but we never want to be in. It's kind of a fantasy -- that I kind of want to know what it's like in some strange way. But I don't want to experience it for real.

Those types of games, no matter what genre it is, I think that's appealing to us as humans. It's tingling, like, "oh this could actually happen for real." Different styles of games have that appeal in different ways.