A recent Kotaku post cites "one reliable industry source" to suggest that the still-unannounced successor to Microsoft's Xbox 360 will somehow prevent used games from being played on the system. The idea remains an unconfirmed rumor, of course, but it's something that members of the game industry have floated repeatedly in the past. It's also a move that would likely find hefty support from publishers looking for a way to stop what they see as erosion of their profits thanks to used games (the reality is a bit more complicated than that, but we won't rehash that old argument here).

The renewed debate got us wondering, though: how might such a used-game prevention system actually work on a technical level?

Kill the disc

The simplest way to stop used game sales, obviously, is to prevent people from having a physical game to sell in the first place. That would mean a purely online marketplace for the next Xbox, building on top of the substantial groundwork laid by the current Xbox Live Marketplace—which already sells a wide selection of full retail games. In the aggregate, Marketplace customers don't seem to mind that they can't resell their purchases (the added convenience and generally lower prices compared to retail might have something to do with this).

But eliminating retail games entirely would totally lock out the substantial minority of Xbox owners that still don't have broadband Internet access at home—a 2010 study estimated that 27 percent of Xbox owners fell into this group. And even those with slower broadband connections might not enjoy being forced to spend hours or even days clogging up their pipes to download gigabytes of game data.

All hail the kiosk

Microsoft could also prevent used game sales while continuing to offer games at retail, but such a move would likely require an entirely new system of distributing those discs. Picture this: instead of a wall of "Xbox Next" discs towering over you at your local retailer, you're instead confronted with a line of interactive, touch-screen kiosks. Once you've browsed the selection and decided on a purchase, you insert a digital key cartridge that came with your system.

The kiosk then gets to work burning you a unique copy of your game on disc, encrypted to run only when that key cartridge is in the system. Using a portable, physical key has the added benefit of allowing players to take their games over to a friend's house, and the ability to continue playing their games if their original system breaks down. Such a kiosk could even print an instruction booklet and a disc case cover, for those dead-enders who are still wedded to their old ideas about what a retail game should include.

Sound crazy? Microsoft is already testing a similar, burn-on-demand strategy with Windows software kiosks in its Microsoft Stores, so adding a bit of digital-key-based encryption to the mix would seemingly be relatively simple. Actually implementing this kind of top-to-bottom change in the way Xbox game discs are distributed would be harder, but it would provide fringe benefits by revolutionizing the supply chain management for Microsoft and its publishers.

The up-front costs to manufacture and install thousands of these kiosks would be substantial, but in exchange publishers will never again have to coordinate the complicated, worlwide rollout of millions of individual discs to far-flung retail locations — just upload the code to the kiosk network when it's ready. Retailers would likewise no longer have to worry about ordering too many or too few of a specific game at launch, since the system's entire library could theoretically be available for on-demand burning from a few massive hard drives in the back room.

Build it into the disc

If messing with the entire video game supply chain seems too onerous, Microsoft could embed an anti-used-game solution into the physical medium itself. While rumor has it that the next Xbox will support Blu-ray discs (a possibility made a bit less likely because of Sony's financial ties to the format), the system could easily sport an entirely new, proprietary disc format designed by Microsoft.

Not only would the new format be theoretically harder to pirate, but the addition of a small, one-time-writable section on the disc would allow each new purchase to be "branded" with a unique personal identifier the first time it's loaded (this could easily tie in with the kind of physical key described above). Some sort of proprietary flash memory cartridge for retail games could work in a similar fashion, though such mass storage is unlikely to be cost-competitive with high-capacity discs for a while yet.

An entirely new format for physical game media would likely increase Microsoft's manufacturing costs, preventing the company from using off-the-shelf disc drives in the hardware or mass-produced disc standards for the software. Still, those costs might be worth it if they gave Microsoft the ability to say to publishers that its system is the only one where every game people play is one they had to buy new, straight from the publisher.

The endgame

All of these potential used-game-blocking methods would probably just be transitional, in any case. By the time the follow-up to the next Xbox is ready, a persistent, high-speed internet connection could easily be as common in the developed world as a land-based phone line was 30 years ago. At that point, the only thing stopping a console maker from tying each and every purchase to a unique user for all time is the potential player outrage over such a move.

Then again, if it meant never having to go to a GameStop again, players might consider it a fair trade..