MMO Diablo III will offer players the chance to use real world currency to trade game items.

The service will be on an item by item basis via an eBay style auction house system and entirely optional. Gold based auction houses will be available for players who don't wish to spend their money in-game.

Blizzard explained its motivations in an official statement, citing player behaviour and security.

"The item-based nature of Diablo game play has always lent itself to an active trade-based ecosystem, and a significant part of this trade has been conducted through unsecure third-party organisations."

"This has led to numerous customer-service and game-experience issues that we've needed to account for. Our primary goal with the Diablo III auction house system is for it to serve as the foundation for a player-driven economy that's safe, fun, and accessible for everyone."

Players can purchase gold, weapons, armour and runestones via their registered accounts. Blizzard will not sell "game play affecting" items, and stated it has no plans to post items directly to the auction house, leaving trading to the players.

When selling, players can use the money they earn to purchase other other Diablo III items through the auction house, purchase products, such as World Of Warcraft subscriptions, or claim the cash through third party services.

For each item sold for real currency players will be charged an unspecified "nominal fixed transaction fee" by Blizzard, which will vary by region and whether or not the item sold. Players will also be charged a fee for withdrawing sales proceeds from their account.

Blizzard has said it will not be introducing the system to its other MMORPG, World Of Warcraft, due to differences in the game play. It also clarified that it has no plans to provide support for the auction house system to mobile devices.

Diablo III still has no official release date, but is currently recruiting players for a beta test. Diablo II was released in 2000, but still has a large online audience.