Just one day after announcing a release date for its new expansion, Heart of Thorns, developer ArenaNet unleashed even more major news for massively multiplayer RPG Guild Wars 2.

In a press conference at the Penny Arcade Expo, ArenaNet president Mike O'Brien and Guild Wars 2 game director Colin Johanson surprised fans by announcing that the core Guild Wars 2 is officially available to play for free starting today.

In an interview with Polygon earlier this week to prepare for the announcement, O'Brien told us that this shift to free for the base game doesn't change the studio's core approach buy-to-play, a model he has "been championing since the original Guild Wars a decade ago."

"It's just such a clean business model," O'Brien said. "You buy the game, you can play it as long as you want for no monthly fee. We love that clarity. We love that customers who bought the base Guild Wars 2 got more than 40 major content releases for free, no monthly fees."

Instead of changing their business model, O'Brien says making the core Guild Wars 2 experience free is more about removing barriers for entry, another key focus of the developer.

"Guild Wars 2 is the game about tearing down those barriers"

"We've seen cases in the industry where a game is buy-to-play, it comes out with expansion packs, and you want to get your friends into the game, but they can't just buy the latest thing and play with you," said O'Brien. "You have to buy the prerequisites. You have to buy the base game and each expansion pack just to be qualified to buy the latest. It's just a barrier to entry. Guild Wars 2 is the game about tearing down those barriers and making it easy to play with your friends."

O'Brien confirmed that the studio will not change the Black Lion Trading Company, its hub for real-money transactions which has been in the game since launch, in order to get more money out of free players. The Black Lion Trading Company allows players to purchase mostly cosmetic items using gems, which are primarily attained through spending real money.

"We're not using the phrase 'free-to-play' for Guild Wars 2," O'Brien said. "Some people will call it that. But there's that stigma that it's a different business model. We're not actually doing that. We're not going back and changing the way the game is monetized. We're not going to make it so it starts free but has its hand out asking for money. It's the same Guild Wars 2 that it's always been and the same gem store that it's always been."

During the PAX press conference today, O'Brien confirmed some restrictions related to free accounts. For example, free players will have less inventory space, will have a limit on how often they can begin new whispered conversations and will not be able to send mail to players. Free players will also have to reach level 60 before they're allowed to take part in Guild Wars 2's world versus world mode.

O'Brien declined to comment on whether Heart of Thorns or other future expansions may also become free upon the release of subsequent expansions for Guild Wars 2.

"If you love Guild Wars 2, we think you're going to buy Heart of Thorns," O'Brien said, explaining why offering the core game free makes sense for ArenaNet. "That's our bet. Our bet is that we still believe in buy-to-play, but all we want you to buy is Heart of Thorns."

"If you love Guild Wars 2, we think you're going to buy Heart of Thorns"

With that step to appeal to new players, the developers also went on to reveal a new raiding system that will be added to the game with the Heart of Thorns expansion to satisfy the hardcore player base that already exists. As popularized in other MMOs, raids will be a 10-player experience challenging groups to overcome extremely difficult bosses. However, ArenaNet is putting its own special spin on raiding.

"Raids in MMOs come with a lot of traditional barriers that we believe we can remove or change to get rid of the some the headaches that people who love raids normally associate with them," Johanson told Polygon.

One of those barriers Johanson pointed to is a heavy focus on user interface and "watching a lot of UI bars move up and down." Johanson said that Guild Wars 2 raids will be a lot more focused on watching the actual action unfold on screen, including active combat, dodge-rolling and working with allies to perform combo attacks.

Johanson noted that Guild Wars 2's raiding system is also well positioned to take advantage of the game's unique approach to player roles — which is to say that there are none.

"If you look at what the experience is like trying to form a party for traditional raiding, the challenge is that you have to have three healers and four damage-dealers and three tanks," Johanson said. "The Guild Wars 2 combat system doesn't put us in a situation where you have to do that. It's all about playing the profession that you love and setting up your build to support and work with the other people in your party to overcome the challenge. You're not sitting in a lobby waiting 40 minutes for your healer to get online. Nobody has to go player a character they don't want to play just so that the party can raid."

"You're not sitting in a lobby waiting 40 minutes for your healer to get online"

Perhaps most surprisingly, Johanson said that Guild Wars 2's raids will avoid the gear cycle that's common in other MMOs. The Heart of Thorns expansion will not add new levels nor new tiers of gear to the game, so players will not outgrow a raid's difficulty and make the older content obsolete.

"We think that raiders don't want it to just be a big deal when they beat a raid," said Johanson. "They want it to be a big deal six months later. They don't want that raid to get easier. Our progression system allows us to not have content get easier later on. It's always just a test of whether you can use your skills and abilities to beat it. That's it."

Instead of earning increasingly powerful gear from Heart of Thorns raids, players will receive new mastery skills and cosmetic items to show off that they've completed difficult content. The first Guild Wars 2 raid will be released in three wings, with the first wing opening up "a few weeks" after the release of Heart of Thorns. Beyond that, Johanson promised that new raids will become a key element of Guild Wars 2's live experience and will be available via free updates for anyone who has purchased Heart of Thorns.

Guild Wars 2: Heart of Thorns will release on Oct. 23. If you've never played the MMO before, you can sign up and play it for free now on the official Guild Wars 2 website. For more information on Guild Wars 2, check out our review.