Activision Blizzard is to start testing a new system that will allow World of Warcraft players to purchase items in-game using real money.
It is one of several new features recently added to World of Warcraft in a bid to attract new players.
Previously, items could only be purchased using real money in out-of-game auction houses, whereas in-game items were bought using gold pieces collected during quests.
However, Activision Blizzard is currently using only certain regions of World of Warcraft to test in-game, real-money purchases. The first item available to buy using real currency is the Enduring Elixir of Wisdom, which is available only to characters of level 85 and over and allows them to double the amount of experience points they earn from completing tasks.
As well as the new purchasing system, Activision Blizzard has recently launched an expansion pack for World of Warcraft called Mists of Pandaria, which allows users to play as a race of warrior pandas.
World of Warcraft is also now free to play until your character reaches level 20. After that point, players have to pay an £8.99 monthly subscription fee.
These additions mark Activision Blizzard's effort to retain World of Warcraft's player base, which has declined in 2013. According to the company's financial results for this year's first quarter, approximately 1.3 million subscribers left World of Warcraft, bringing the global number of players down to around 8 million.
In 2010, the number of World of Warcraft subscribers peaked at 12 million.
Despite Activision Blzzard's efforts to retain subscribers, World of Warcraft users have raised concerns that in-game, real-money purchases will in fact cause more players to leave the game.
"Offering payment for in-game item services is a great way to kill a game," wrote Xethorsiph, a user of the World of Warcraft Battlenet forum. "Such games are often called 'pay to win' because you end up at a point where the only way to be on top in-game is to spend out-of-game money.
"Such games inevitably crumble, because only a precious few are able/willing to invest their money in that way, and so they end up being the only ones around. With such a small player base, the game inevitably closes."
It has not yet been confirmed when in-game purchases will be rolled out to the rest of World of Warcraft.