The R4 looks like a simple piece of plastic. It is just a couple of centimetres square, a few millimetres thick and unbelievably easy to use. For Nintendo it is the Christmas stocking filler from hell.

Made in China, available for sale over the internet and now doing a roaring trade on the streets of Tokyo, the R4 has emerged as perhaps the ultimate video game piracy tool.

Costing a little more than £20, the device is a virtually unlimited passport to illegally downloaded software titles for the Nintendo DS – the handheld games console that has taken Japan, and much of the world, by storm.

In the Akihabara electronics district of Tokyo, where the R4 has just gone on sale, the product is ubiquitous but deliberately shrouded in mystery.

Many stores advertise that they have the R4 in stock and describe sales as “very strong” but refuse to say what it actually does, for fear of potentially dire legal consequences.

“New R4 shipment has finally arrived! You know what it does! Absolutely no questions will be answered concerning this product . . .” reads the sign outside one electronics store just off the main Akihabara drag. “Guaranteed for one week only! Of course we can’t explain what the R4 will do . . .” reads another in the store next door.

Other shops in the area are visibly nervous about it because it falls into what they refer to as a “grey zone” – the product itself is not illegal – but nearly everything that a customer would do with it probably is.

A floor manager at Iosys told The Times that the store was considering pulling out of sales following complaints; high street electronics shops refuse to stock it because it is legally questionable and damages sales of legitimate games software.

In the hands of the 35 million DS users around the world the R4 chip has the potential to deal a heavy financial blow to Nintendo and to the dozens of software developers that make games for the machine. Nintendo is Japan’s third most valuable listed company with a stock market value of more than $85 billion (£41 billion) and revenues of $7.8 billion in 2006.

The R4’s function is simple: it is a direct conduit for illegal game downloads and other unofficial software. Built to fit into the DS’s existing game cartridge slot, the R4 will transfer on to the console anything saved on a removable flash memory chip.

Most DS games appear on the internet and are ready for downloading within a few days of the legitimate version going on sale. Vidoes on youtube. com offer first-time users of the R4 an easy-to-follow tutorial in making the device work. Salesmen even quietly suggest visiting youtube.com rather than attempting to decipher its Chinese instructions.

As an experiment The Times obtained an R4 chip and downloaded free of charge on the internet ten new Nintendo DS games – worth about £400. The games, one of which had gone on sale only the day before, worked perfectly. The entire process took less than half an hour.

The R4 is not the first time that China has exported the means of games piracy to the outside world. Games software is heavily pirated and available throughout Asia. However, the R4, said one industry analyst, takes games piracy into a new level.

Beyond the purchase of the device, the user never has to go to stores to buy pirated software. “The R4 gives ordinary users the ability to sit at home and just browse the internet for any game that takes their fancy. A few clicks of the mouse and it is theirs free. Unlike previous piracy tools, the technology is not intimidating,” he said.

“We are keeping a close eye on the products and studying them. But we cannot smash all of them,” a Nintendo spokesman said. Some believe the R4 may have the same disruptive effect on Nintendo’s business model as early music file-sharing sites such as Napster had on the record industry.

Testing the law

— In September 2006, a US Court ordered French company Divineo SARL to pay $9 million for selling modification chips similar to the R4

— Legal action by the recording industry the music file-sharing site Napster.com into bankdruptcy in 2002. It has now been rebranded as subscription service Napster 2.0

— The iTrip clips on to an MP3 player to transmit music via an FM radio signal. Popular with drivers, the tool was legal to buy but illegal to use, until Ofcom bowed to pressure and legalised it last year

Sources: Times archives