Currently, only two virtual reality platforms exist on Windows PCs: the Oculus Rift and the SteamVR-powered HTC Vive. Each set has its strengths and weaknesses, but until recently, they at least both offered limited compatibility with their rival's software stores. Oculus headset users can pick through compatible games on the SteamVR store and interface, while HTC Vive wearers could install a fan-made patch to play Oculus software.

SteamVR still plays nice, but the other side changed its tune on Friday with a major Oculus app update for Windows PCs, complete with advertised "updates to platform integrity checks." It didn't take long for the team behind that aforementioned HTC Vive patch, dubbed "Revive," to announce that those "integrity checks" appeared to block users' access to Oculus games on unauthorized hardware.

"Oculus has added a check [to look for] whether the Oculus Rift headset is connected to their Oculus Platform DRM," Revive developer "CrossVR" posted to the Vive Reddit community on Friday. "While Revive fools the application [into] thinking the Rift is connected, it does nothing to make the actual Oculus platform think the headset is connected."

When asked about the update, Oculus spokesperson Jim Redner told Ars that the app's new entitlement check was added "to curb piracy and protect games and apps that developers have worked so hard to make. This update wasn’t targeted at a specific hack." He also claimed that the entitlement check's functionality is "common in commerce platforms that validates a user has purchased a piece of software." However, the Revive team's representative alleged that the issue isn't a check for legitimate software purchases but for whether Oculus hardware is connected—and even suggests a workaround of attaching an Oculus development kit model so that a Revive-patched game can then operate normally on an HTC Vive headset. We have asked Oculus to clarify these contradicting claims and will update this report with any response.

However Oculus wants to describe this update, users have wasted no time in quoting company founder Palmer Luckey's own statement about such issues. Luckey took to Reddit in December of last year to respond to claims that Oculus might ever lock its software platform in any way, particularly in terms of inviting other headset owners to play Oculus games.

"If customers buy a game from us, I don't care if they mod it to run on whatever they want," Luckey wrote in December. "Our goal is not to profit by locking people to only our hardware—if it was, why in the world would we be supporting GearVR and talking with other headset makers? The software we create through Oculus Studios (using a mix of internal and external developers) are exclusive to the Oculus platform, not the Rift itself."

Oculus representatives did not respond to questions about Luckey's December statement. The Revive development team has pledged to circumvent the Oculus app's latest block but said that "it will be challenging to circumvent this check while keeping the DRM intact."

Revive was originally built to translate positional calls of a user's x, y, and z axes from one VR software platform to another, as opposed to interacting with any DRM or payment-proof system. As originally launched, Revive required background running of Oculus's app to check for its DRM calls. Friday's block came after a recent update by Revive to make it easier to load Oculus software from within the HTC Vive's virtual "chaperone" environment.