World of Warcraft maker Blizzard Entertainment today unveiled an auction system for selling in-game items for real-world currency in its latest multiplayer game, Diablo 3.

Players can sell the equipment they get from monsters they kill in the game — like swords and armor — either for in-game currency or for real-world currencies like U.S. dollars. The whole process is automated and happens through an in-game interface rather than a third-party marketplace. Blizzard Entertainment will take a small transaction fee from the seller, similar to how Facebook and Apple handle transactions through apps or Facebook Credits.

Blizzard Entertainment frequently spars with companies that try to sell World of Warcraft weapons and in-game currency. It hunts down and bans “gold-farming” accounts that can give some players a competitive edge over other players who earn gold through traditional means in the game. Diablo 2 also faces a similar problem with in-game equipment, which is what likely prompted Blizzard Entertainment to make the move, Wedbush Securities managing director Michael Pachter told VentureBeat.

“It’s an acknowledgement that people will sell items (as gold farmers), and an attempt to control the process and collect a fee for providing an auction,” he said. “I think it’s a smart idea.”

Unlike social gaming company Zynga, which makes most of its revenue from selling virtual goods in its games, Blizzard Entertainment said it does not plan to sell items. The auction house is only there to facilitate transactions between players and give them a way to earn money by playing games, the company said.

Kleiner Perkins Caufield & Byers partner Bing Gordon, an investor in Zynga, said in June that gamers should generate around $3 each hour in value if an online game is going to be successful. While he was speaking figuratively, the new system in Diablo 3 will let gamers actually achieve that golden value.

Blizzard Entertainment is also now letting account holders opt in to a limited beta for the game. We earlier reported that a beta was likely near after a number of signs indicated that the company was just about ready to pull the trigger for a beta program.

Diablo 3 is one of the most anticipated titles of the year. The last Diablo game came out in 2000 and still boasts a big player base. It’s nothing compared to Blizzard Entertainment’s most popular online role-playing game, World of Warcraft, which has around 11.4 million subscribers. But the game’s hack-and-slash and loot-seeking formula proved to be incredibly popular and the game has persisted for more than a decade. It even inspired a number of dungeon crawler copycats like Torchlight.

The Diablo games allow anywhere from two to eight players to jump into discrete games with randomly generated dungeons. The goal is to prevent the forces of Hell from taking over the world by defeating Diablo, the lord of terror, and his cohorts. Players chase after powerful items and weapons to use against other enemies and players or for trade.

Blizzard Entertainment announced Diablo III at its yearly convention, Blizzcon, in 2008. The company unveiled a new player class at each subsequent Blizzcon, including the final class at last year’s convention. Diablo has taken somewhat of a backseat to Blizzard Entertainment’s larger game, World of Warcraft, and its newest release Starcraft 2: Wings of Liberty.