This page is our investigation of cross-play feature in game called Baldur's Gate 3. We also want to mention that - we always put manual efforts to find the precise, valid, and what is more important official information about different game features without using AI.
Games can have different cross-play combinations, for example the game can have cross-play between PC, Playstation 5, Xbox X|S, but not between old generations like: Xbox One, Playstation 4, PC. To avoid any misinterpretations, we group them into so called "cross-play variations".
Any store inside the cross-play variation have a cross-play only with a store in the SAME variation. We also want to notice, that we put into variation not platform, but store + platform. That is required because some games, for example, can have cross-play between a Playstation 5 and Steam, but not Playstation 5 and Epic Games.
Baldur's Gate 3 has full cross-play between all platforms, so players on PlayStation 5, Xbox X|S, and PC (Steam) can play together. This information is official, and the "cross-play" feature was part of patch 8, which is the final one. You can read by yourself here.
To add some clarity and remove any possible confusion, I have to say that the game didn't have cross-play at the release, but as was mentioned before, it received it with one of the patches.