LOS ANGELES—When Microsoft announced the first details of its next game console Sunday, it said that "thousands of games across four console generations will look and play best on Project Scarlett." In a video follow-up focused on backward compatibility posted Monday, the company clarified that its goal is that "every single game you play on Xbox One today [will] work on the Scarlett device."

That would be a change from previous Xbox console generations, which have only supported a significant subset of previous generations' titles through software updates. It sounds like getting Xbox One games to run on Project Scarlett will also take some specific software-level effort on the part of Microsoft, rather than being supported directly at the hardware level.

"Ensuring every game that runs on Xbox One is going to run incredibly well on Scarlett will take a ton of commitment and time from our team," Microsoft Head of Xbox Phil Spencer said in the video. "The team is dedicated. We're ramping up our testing facilities to make sure we can hit the ground running and make sure that stuff works."

















To account for that testing time (and to allow the backward-compatibility team to focus on Scarlett), Microsoft also announced that, "after this week, we have no plans to add additional Original Xbox or Xbox 360 titles to the catalog on Xbox One." That ends a program that started in 2015 with 104 Xbox 360 titles and has since grown to include 568 Xbox 360 games (including 15 new ones announced today) and 39 games for the original Xbox (eight new ones announced today). A total of 69 games across both generations have also been "Enhanced" for the Xbox One X, with new textures and other enhancements to look better on 4K displays.

Microsoft reminded readers of its blog today that backward-compatible games supported on Xbox One can be purchased digitally or played "with the disc you already own." Reading between the lines a bit, that post suggests Project Scarlett will also have a disc drive to ensure that through-line continues (though Microsoft has not officially confirmed any such disc-drive plans for its next console).

While the initial run of PlayStation 3 consoles was able to play every game from the PlayStation line, Sony phased out that feature in subsequent hardware revisions. The PlayStation 4 only supports a selection of earlier PlayStation games through PlayStation Now streaming. Sony has said that the successor to the PlayStation 4 will be backward-compatible with games for that system.