Xbox One will not be backwards compatible with Xbox 360 games | The Verge: " .. . . the new Xbox One console will have no backwards compatibility whatsoever.
"No, there's not," said Whitten, when we posed the question. "The system is based on a different core architecture, so back-compat doesn't really work from that perspective."
That means that Xbox 360 discs won't work, but also extends to Xbox Live Arcade downloadable titles. Anything that was designed for the Xbox 360 will have to be rebuilt, and it sounds like Microsoft doesn't plan to do so. . . ."
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