Ever since I started playing Mass Effect 3 Multiplayer, the privacy setting in mission settings is locked. I own the legendary or best edition so if there was a code in there I missed it. Is there something I have to do or get a certain amount of characters to level 20?
When starting a multiplayer game,you have two options: Quick Match and Create New Match.
With Create New Match, you can choose either private game or public game. Public game means that anyone can join. Private game means that only people you invite can join. (And I think your friends can also join without invitation.)
With Quick Match, you search for a game that already exists. And it doesn't make sense to look for a private game, so the option is locked.
To sum up, if you want to create a private game, use Create New Match, not Quick Match.
Also, there are no requirements for this, you can always do it .