I guess this has already been asked by other people in the past, but I'll ask anyway:
Private rooms with password?
I can suggest for example when selecting the option "private room", it generates a 4-digit password, plus, a "hide room number" option if it is going to be streamed or something similar.
I want to expose my suggestion, showing you a specific example that the video game Brawlhalla owns.
Image 1: As you can see, regardless of the game, Brawlhalla has a very interesting custom game creation system.
It has 3 options:
Image 2: When you select the Create Room option, a second window appears that allows you to choose between Private Room and Public Room.
When you create the game, the room information appears with the server location and his room number.
And as you can see, there is a check box that allows hiding the room number in case of live transmissions for unwanted people to enter the room.
Image 4: If we go to Join Room, we will see a panel of numbers, where you can enter the room number that we want to join.
Image 5: And last but not least, if we go to Browse Rooms, it will show us a window with all the open rooms available.
And that's it, I'll be open to any criticism, suggestion, etc.
I believe that this system will facilitate the creation of games with friends, enemies and competitive/casual tournaments.
You can simply uncheck the "auto join players" button, and new people who come into the room have to be approve to play, you do that by right clicking and click "assign spot", you can also unassign afterwards if you accidently assign someone.