Sony has told developers that new PS4 titles must also work on PlayStation 5 starting in July.

Beginning July 13, Sony has informed PlayStation 4 game developers that any new titles submitted for certification must be compatible with PlayStation 5.

This means that all PS4 titles accepted for testing after the middle of that month are technically forwards compatible, meaning they can be played on Sony’s next-generation machine; however, it is up to each game’s developer to ensure this.

The developer paperwork that Eurogamer obtained from PlayStation‘s internal Partner website outlines an option that developers must select to indicate that their game has been evaluated for compatibility with PS5 hardware. This option was included in a new edition of Sony’s PS4 software developer kit at the end of April.

Sony has informed developers that it will approach them individually with information on how to test PS5 compatibility in the order of their respective projects’ releases.

More documentation clarifies what “compatibility” entails. Only if a game’s submission code works without errors on Sony’s next-generation console and provides the same functionality on PS5 as it does on PS4 will it be considered PlayStation 5 compatible.

As a result, a developer can’t identify a game as PS5 compatible while excluding support for a specific mode on next-gen hardware.

Sony’s requirements for patching current games and remastering previously published titles are detailed in these developer notes.

If a game were submitted to Sony before July 13, 2020, any new patch or remaster released after that date would not be required, but it would be “highly encouraged.”

If a title was submitted to Sony after July 13, 2020, every future patch or remaster for that game must maintain PS5 compatibility. Once a game has been certified as PS5 compatible, it must remain so.

It’s important to note that all of this only applies to games submitted to Sony after July 13, not to games launched after that date. To ensure that Sony’s certification team can approve the game in time, submissions are typically made well before release.

For example, Sony’s Ghost of Tsushima will be released on July 17 but passed certification before the July 13 deadline. It won’t have to be backward compatible with the PlayStation 5. However, as one of the last surviving PlayStation 4 flagship titles, it will almost certainly be supported on PlayStation 5. (and indeed, Eurogamer has separately heard this will be the case, alongside fellow upcoming exclusive The Last of Us 2).

However, while approved software has the technical capability to work across generations, Sony has yet to explain how it will do this in practice.

Many third-party publishers have already stated that they will support Microsoft’s Smart Delivery technique for cross-gen ownership on Xbox, which serves the best version of a game for the platform you are using. Ubisoft and CD Projekt Red will leverage this to give cross-gen ownership for Assassin’s Creed Valhalla and Cyberpunk 2077, respectively. (In the meantime, EA has opted to offer a limited-time “upgrade” window for some of their titles.)

In terms of previously released games, Microsoft promised a year ago that the Xbox One’s complete (non-Kinect) back library, as well as all matches from its existing Xbox 360 and original Xbox backward compatibility program, will be available at the Series X launch. And, as Microsoft revealed to Digital Foundry in March, it will supply this with automatic enhancements, such as the inclusion of HDR.

PlayStation also strives to ensure that PS4 titles work on the PS5, after earlier stating that it would forward “problems that require modification” to developers.

“Backward compatible games are expected to operate at a higher frequency on PS5, allowing them to benefit from higher or more consistent frame rates and possibly higher resolutions. We’re assessing games title by title to see if any flaws need to be addressed by the original software creators. “PlayStation sent a letter in March. “Mark Cerny’s presentation included a look at the Top 100 most-played PS4 games, showcasing the success of our backward compatibility efforts. As we get closer to launch, we’ve already tested hundreds of games and are planning to test thousands more. In the months ahead, we’ll share updates on backward compatibility, as well as a slew of other PS5 news. Keep an eye out!”