Hi-Rez Studios, the developer of Smite, Paladins and Realm Royale, among others, will introduce crossplay to those three games. However, the PlayStation 4 is an exception; only players on all other platforms can play together.
According to Hi-Rez, the feature will come to Smite and Paladins in January of 2019. Smite is available for Windows, macOS, Xbox One, PS4 and the Switch starting January 24th. Paladins is available for the same platforms.
Realm Royale is in Early Access for Windows and the PS4 and Xbox One versions are in closed beta. Crossplay will be introduced there at the time of the actual release, for which no date has yet been set. However, that is contradicted by PC Gamer and Gamasutra, who write that Hi-Rez states that crossplay between Xbox One and Windows will be available sometime during this beta.
Cross-progression, or the portability of unlocked gear and abilities, is also introduced. With Smite and Paladins this happens simultaneously with crossplay and with Realm Royale at a later moment.
Smite is a popular third-person moba, Paladins is an online team-based first-person shooter reminiscent of Overwatch, and Realm Royale started out as a battle royale game mode for Paladins, but then became a standalone free-to-play game .
Sony has long been the mainstay when it comes to crossplay. With Fortnite: Battle Royale, for example, Sony has stated for a while that “the best experience can be found with the PS4” and that crossplay can only destroy that. In the end, Sony has taken the plunge and now seems to determine per game whether it wants to be open to crossplay. In any case, Hi-Rez states that it is “ready to support other platforms in terms of crossplay as soon as the opportunity arises.”
Smite on Xbox One