https://www.theverge.com/2018/3/12/17111546/microsoft-sony-fortnite-cross-play-ps4-xbox-one

Fornite cross-play between consoles and PC, Mac, and mobile is coming soon, but PlayStation 4 owners won’t be able to play against Xbox One gamers. Epic Games revealed this weekend that Xbox One players will be able to play Fortnite with PC, Mac, and mobile players, but not PS4 players; similarly, PS4 owners will be able to play against all platforms except Xbox. In a new statement to Kotaku, Microsoft is directing the blame squarely towards Sony.

“We’ve worked closely with Nintendo to allow cross-network play between Xbox One and Switch and our offer to do the same with PlayStation players still holds,” says a Microsoft spokesperson. “For any other questions regarding Fortnite cross-network play between Xbox and PlayStation, please reach out to Epic or Sony directly.” The Verge has reached out to both Sony and Epic Games, but neither company has yet to respond.