Sony won't allow Fortnite players on PlayStation to play against their friends with other consoles – because those people are having inferior experiences.
The company might allow people to take part in cross-platform play on other titles, said the company's boss. But Fortnite on PlayStation will not get that privilege, he said.
And that's because the best experience is to play on PlayStation, he said. So allowing other people to play would be a compromise.
The technology giant caused controversy earlier this year when the battle royale game launched on the Nintendo Switch, but existing PlayStation players discovered they could not move change platforms on the same account - despite Xbox and PC players being able to do so.
In spite vocal protests from gamers in response, Sony has not yet changed its policy.
Speaking at the IFA technology show in Berlin, Sony chief executive Kenichiro Yoshida said he felt playing on the PlayStation 4 was the best experience for gamers and therefore should not be compromised.
"On cross-platform, our way of thinking is always that PlayStation is the best place to play. Fortnite, I believe, partnered with PlayStation 4 is the best experience for users, that's our belief," he said.
"But actually, we already opened some games as cross-platform with PC and some others, so we decide based on what is the best user experience. That is our way of thinking for cross-platform."
Fortnite has amassed more than 125 million players since the launch of its battle royale mode last year, with many choosing to play on mobile devices such as their phone or tablet.
Mr Yoshida said Sony was aware of the increasing importance of mobile gaming, adding the company needed a "growth strategy including mobile".
He added he welcomed the competition from other platforms as well as traditional gaming rivals.
"I think competition is always good. Healthy, fair competition is always good for the industry and growth," he said.
"I think competition with Nintendo and Xbox is a healthy situation."