Online games may be set in fantastical or far future worlds but they share one feature with the real world - the relative scarcity of money.

Life can be tough for the novice characters that players create in games such as World of Warcraft, Runescape and Tabula Rasa because they are unskilled and poor.

While skills will improve as monsters are slaughtered and quests are completed, the scarcity of cash can be a brake on progress for many gamers.

Many fix the problem by turning to a gold seller and buying a chunk of in-game cash, using real world money, to fund their advancement. This is despite the fact that the terms and conditions of many games ban the buying and selling of in-game gear for real money.

Being found out can mean a player is banned and their account is closed.

Money markets

As games rack up more and more players the numbers turning to the money sellers and those who only play to amass, or farm, gold that they can then sell have rocketed.

There are many websites that offer to sell players in-game gold for any and every online title.

For games such as Runescape which have millions of players the numbers involved are staggering.

Geoff Iddison, chief executive of Runescape maker Jagex, said that during 2007 the company took more than 525 billion farmed gold pieces out of its game world. In real money that virtual gold is worth more than £1.3m ($2.6m).

"A lot of this is coming from China," he said. "We had tens of thousands of accounts in China that were just bots working the game to make gold and then sell it."

Mr Iddison said that the gold farmers spoiled the experience for many players by camping out near monsters with the most valuable loot, filling chat channels with spam messages advertising gold, inflating prices and sometimes taking real world cash without handing over the game gear.

In a bid to stem the trade, Jagex changed the Runescape mechanics to make unbalanced trades much harder to do. Mr Iddison said typically game cash was handed over during a transaction for relatively worthless items.

By making it hard for all but dedicated players to conduct such unbalanced trades, Jagex hopes to stifle the farmers.

Early reports suggest the changes are having an impact, said Mr Iddison with complaints about farmers well down on usual numbers.

"We've seen a lot of the bot accounts drop off and the player experience has improved," he said.

Mr Iddison added that Jagex was not wholly against real-money trade, just how it was being practiced in Runescape.

With the right design, he said, it should be possible to make a game that embraces real-money trade that does not damage game play.

Buy and sell

Some game firms are trying to do exactly that. The end of 2007 saw the launch of Live Gamer which aims to make it much easier for gamers to buy in-game goods with the blessing of the game makers.

At launch Live Gamer had the backing of online game makers such as Funcom (Age of Conan and Anarchy Online), Sony Online Entertainment (Everquest and Star Wars Galaxies) and Acclaim (Bots, 9Dragons).

Co-founder Andrew Schneider said that when the service goes live players would be able to buy and sell gold and gear while still in the game world - rather than step outside it and go to a website.

"We're working with the publishers to integrate our client software so that it does not break the fourth wall," said Mr Schneider.

The system would involve a player to player market place similar to the auction houses seen in many games already and which are often the busiest places in the virtual worlds.

Mr Schneider had no doubt that a legitimate place to buy and sell game gear and gold would encourage far more players to try it than do presently given the "horror stories" that have circulated about players being cheated or who have had their account banned.

"There's a better way of addressing the consumer demand," said Mr Schneider.

"We anticipate that well-known market dynamics will occur a secondary market is introduced into any market such as exists in the game worlds," he said. "There's typically uplift for both sides."

But not all game watchers are convinced that real money trading will take off.

Michael Zenke, an editor at online game website MMOG Nation, expressed scepticism about Live Gamer's prospects.

Despite the rampant participation in real-money trade by players, it's still a big taboo to talk about it," he said.

"'Legit' outfits are going to have a hard time getting an edge over the farmers of today, because there are certain companies (EA, Mythic, Blizzard) that will never ally with them," he told the BBC News website.

He expected that Live Gamer would find some success with those players who want a reliable source and a further few who did not like the tactics of gold sellers.

"Otherwise," he said, "I don't see there being much room for traction there."