Allows playing multiplayer games with players on different platforms, allowing players to join together regardless of the platform they own.
Name variations: Cross-play
The first video game about Multiplayer: Cross-platform was released on December 1995.
For each game, at least two platform instances should be tagged with this, otherwise it's invalid (you can't have crossplatform multiplayer with only single platform).
To clarify: this means that, for example, a person on a Mac can play the game with another person on an Xbox.
This does not include the server being available on other platforms than its being played on.