Hussar
Legend
I am not sure why it happens. I provide a 1 page sheet answering those questions before each campaign. Players let me know if they are interested. They are told that there with be a session as a group to discuss concepts with me and the group where all questions are answered.
They post on discord if they want a change etc. Character backgrounds are due 1 week before campaign starts. I work with each player to add information and help them with any setting needs or info.
It is really not that difficult. I have never had anyone in any group that I have run or played in just bring a random character.
Which, if they are, then they are bringing pretty much just a random character. They come to you with a completed background, subject to your approval, and, presumably so long as it doesn't contradict anything in your setting notes, that's a given.
Which is pretty much exactly what I was talking about. Everyone comes to the table with a fully formed character that has zero connection to any of the other characters in the group because all the characters were made in isolation. I think that we're probably having the same experience, but, spinning it in very different ways.
Let me ask this. You posit a fairly standard Sword Coast campaign. Say Hoard of the Dragon Queen. I come to you with a human fighter from Beregost who happens to be in Greenest on a holiday. Is that enough? Or do I have to sit down with you and/or any of the other players and collectively collaborate on my character and background? Because if my character is okay, then, that's precisely my problem. A fully formed background created with zero input from the DM or the other players.