On Saturday, ArenaNet announced Guild Wars 2's first expansion, Heart of Thorns. The day after, I spoke with Mike O'Brien, president and co-founder of ArenaNet, and Colin Johanson, Guild Wars 2 game director. Here's that interview, covering both Heart of Thorns, and what it means for the game and its future.

PC Gamer: Are you pleased with the reaction to the announcement?

Mike O'Brien: Definitely. We just had a fan gathering last night and got to hang out with a lot of Guild Wars players. Honestly, players are thrilled with what they saw yesterday. It's such a pleasure to hang out with them right now.

PCG: This expansion is unusual in that the lead-up has been almost two years in the making. Do you think it's going to be hard to balance the needs of players who've played all Living World episodes, returning players who have maybe only completed the main story, and any new players coming to the game for the first time? A lot has happened.

Mike: Well definitely a lot's happened. One great thing about Living World: Season Two is that anyone can play Living World: Season Two. Even down the road people can play Season Two. Certainly, right now, I recommend that anybody who's excited about Heart of Thorns should get into the game and play episode eight. Episode eight weaves right into the story of Heart of Thorns. Anybody who wants to set up for themselves what the story of Heart of Thorns is, play it now.

PCG: One of the big revelations at the end of episode eight was that the Sylvari were from Mordremoth. They're corruptible. How are you progressing that given that they're also a playable race?

Colin Johanson: You know, I think that's a great question that we are looking forward to showing people when they get in and play the game. We don't want to give away too much of that right now, other than to say that if people don't have a Sylvari character yet, it's a great time to make one and have one ready to go for Heart of Thorns. It's really going to be an interesting experience, and a twist that a lot of players are really excited about what it could mean for the game.

PCG: How big is the new region, Heart of Maguuma?

Colin: You know, we picked a different philosophy for building out this region. We're really focusing on doing less broad development and more deep development. I think historically you'll see expansions for MMOs do a bunch of maps that players progress through very quickly and leave a wasteland of empty worlds behind them. We're really focusing on doing less total maps and instead making them really, really deep, filled with a ton of replay value; a ton of content to explore and see. A lot of content that, as you progress through it, you'll see for the first time and you won't be able to get there, or you'll encounter challenges that you can't overcome the first time that you see them. As you progress and build through our mastery system, you'll be able to return and overcome those challenges and get to those places you couldn't get to the first time through. And so we're really focusing on: let's do a little bit in the grand scheme of things; let's do a smaller sized area for total scope, and focus really on depth. Make maps that have an incredible amount of replay value, so every time that you log in you can go back in there and have a new experience. Have an incredibly deep experience and enjoy playing over and over again in that content.

I think in a lot of ways, philosophically, you look at what makes a lot of games have really good replay value, and often times you look at competitive games where a lot of them have a game mode and people will play it over and over again for years. We're really trying to take that concept and that experience with our PvE and provide that same type of experience where you don't have a ton of maps that you tear through and go away. Instead, they have really deep experiences that you can play over and over again and have an amazing time with.

PCG: Does that mean you're pushing the dynamic event system much further this time around?

Colin: Yeah, I would say: every core pillar of what makes the Guild Wars 2 open world experience what it is, we're trying to build on those and build a richer, deeper experience—with our event system, with our content, with the creatures you encounter, with the difficulty of those encounters. We want to build challenging group encounters as part of this experience that you're not going to beat the first time. That you're going to have to learn how to overcome them and build tactics, and you're going to want to come back and play again so you can overcome those challenges again. And it's a really big part of where we want to go, and a part of Guild Wars 2 that we really think we can grow and expand on.

We realised one of the things Guild Wars 2 really needs is a system for clear end game progression that meets the pillars of what Guild Wars is all about.

PCG: In a sense then, it's an end game expansion? A lot of stuff that's comparable—perhaps even beyond—the hardest group events currently in the game. Like, for example, the Triple Head Wurm? Things that players need to work together and plan for.

Colin: Yeah, I think we realised one of the things Guild Wars 2 really needs is a system for clear end game progression that meets the pillars of what Guild Wars is all about. Challenging content that when you encounter it you're not going to beat it the first time. You can use this progression, and build and overcome challenges, and have challenging content that's harder than anything we've ever done, and do it more regularly than we've been able to do it before. I think that is something that Guild Wars 2 needs. I think it's been pretty clear from the experiences over the last couple of years that we've heard. That that's something people would love to see in the game. And that's one of the main reasons we built this expansion.

PCG: How does the verticality of the jungle play into that? Will players be able to see events happening at a different level, and think "I need to get there. There's clearly something happening I want to be a part of"?

Colin: Yeah. Verticality wise, the jungle has the most vertical game space we have ever built in Guild Wars 2. You literally can come at the jungle floor and climb all the way up to the very top of the canopy of the jungle, and the very tree tops above you. The end of our Living World: Season Two episode had the Pact Fleet crashing into the top of the jungle as it was destroyed, and literally the wreckage of that fleet is scattered all over the top of the jungle. And you're going to be able to go up all the way into that top and explore inside the wreckage of the fleet, jumping across the top of the jungle, and using our new mastery system to purchase abilities to master exploration. Like hang-gliding, so you can really experience that 3D space in even better and more deeper ways. And it's going to be filled with locations that you want to get to, and as you build up and earn these masteries, you can start exploring more and more of this incredible amount of vertical space.

Mike: The verticality is really off the charts, I've got to say. When you go into the jungle for the first time, it's really like nothing you've ever seen before.

PCG: Yeah, I'm looking forward to that. One of the cool things about the Silverwastes—when the jumping puzzle was added—was running over the top of the map and looking below as the other players were fighting for the events.

Colin: I think a good example is the concepts we played around with in Dry Top and Silverwastes. The broader experience. The more meaningful content. Events playing all as part of a broader experience—making more of a map-wide experience—and having a lot more replay value to those. I think a great example of what we want to do is to take that concept and take it even further, and build more on top of that. That's been really successful for us, and the jungle is really going to take that and take it to the next level with the event system and with the exploration. That jumping puzzle was certainly a little bit of an experiment for us, looking ahead at the stuff we want to do.

PCG: On stage, you asked the crowd if they wanted new levels and new tiers of gear, and got a resounding "no" back. Is that something you were confident the community wasn't interested in?

Mike: This was a very, very plugged in crowd. I was impressed with the audience at the show. Guild Wars players come to us very savvy about MMOs, and one thing we see over and over with our audience is they've been through it before. They know what it can be if we're not careful, and they are holding us to very high standards. I pretty much knew that if I got up there and said, yeah, this is the expansion pack where we're adding the gear treadmill that they were going to rush the stage and, you know, throttle me. So I had a pretty clear idea of what the fans are looking for. But as we went into every detail about Heart of Thorns on that stage yesterday, that was just such a plugged in audience. They had been anticipating and thinking about every detail of Heart of Thorns.

On the next page: masteries, specialisations and the future of Guild Wars 2.