A developer has created a software patch to make titles bundled with the Rift headset compatible with the Vive.
Currently, it works with only two games - Lucky's Tale and Oculus Dreamdeck. More patches for other games are expected to follow.
However, one user said, the patch may prove tricky to install for those unfamiliar with PC technology.
A developer known as LibreVR put the patch on the Github code-sharing site for anyone to download and use.
Sam Machkovech, a writer for the news site Ars Technica, said it had allowed him to run Lucky's Tale via the SteamVR game-playing system used by the Vive.
The patch also preserves some elements unique to the HTC Vive such as the "chaperone" system that keeps an eye on a gamer's surroundings and warns if they stray too close to walls or other obstacles.
However, the ported game can only be played via an Xbox controller rather than with the Vive's motion controllers.
Mr Machkovech said the patch was significant because, before now, although the Oculus could get at games accessible via SteamVR, Vive owners could not get at many Oculus games.
But installing and running the patch might prove tricky for some because of the combination of files it needed to get games working.
"HTC Vive owners now have a free, simple way to access some of Oculus's most impressive launch offerings," wrote Mr Machkovech.
Oculus has yet to respond to news about the LibreVR patch, although in the past it has said it would be happy for people to change or "mod" its games.
Owners of the HTC Vive virtual-reality headset can now play games made exclusively for the rival Oculus Rift.