PlayerUnknown's Battlegrounds has promised custom matches for some time. Today, they arrive on test servers via an open beta—and while they come free-of-charge at present, developer PUBG Corp may eventually put them behind a paywall so the system "remains sustainable long-term".
As outlined in this Steam Community update, PUBG Corp says custom matches allow players to "play PUBG your way" by customising various aspects of the game, hosting private matches, or tailoring pre-existing War and Zombie Mode game types, among other things.
"Throughout the open beta, custom games creation will be limited to 10,000 concurrent running games to ensure a stable service," explains the dev. "Creating custom matches won't have an associated cost during this phase. However, due to the extremely large amount of resources required to allow custom games to be available to all players, we may change this in the future to ensure everything runs smoothly and the system remains sustainable long-term.
"We're open to your feedback on this system and we'll have more details on this aspect of the system later."
The remainder of the post talks would-be matchmakers through the process of setting up the mode's myriad prerequisites—"map, team sizes, perspective, current player count etc."—while showcasing its new UI too. Check that out in full this-a-way.