Board Game Arena

When I set up a new game, I specify the number of players. Several times recently when I've set up a 4-player game, one of the other players has started the game when there are only two or three players. I didn't think anyone but the originator could start the game -- is there a way to prevent people from starting games with less than the specified number of players?

I think what happens is the the 4th player joins and immediately quits (maybe they joined other tables and they started). As soon as they joined the table auto-starts, but by the time you get to the start game screen they've already quit.