I'm about to start a new campaign and, since I tended to have a bit of bad luck with this in the past, someone recommended me to do a quick Q&A with  potential players for my game. I generally find it a good idea, to make sure you get along and everyone knows what they're getting into. Thing is, I'm not 100% certain what questions to bring up. Anyone able to help me with that? What are some must have things that need to be addressed? Thx for the help in advance and a good day to all of you^^ 

You could do it almost as a pre-session 0. Ask them what kinds of campaigns they like to play in. Ask if they consider themselves to lean more toward the game aspects or the role play aspects. Or things like, on a scale of 1-10, how much do you minmax? Is it more important to follow RAW or to allow players to do cool things that might not technically be permitted. Think about things that have annoyed you about players in the past, ask them about those habits. And try to word the questions as neutrally as possible, so they don't just try and tell you what you want to hear.

Also, you can tell them about yourself. Let them know if you have any table rules, like do you allow any homebrew, do you use any house rules, will you be allowing character creation with Tasha's options. If there's anything you do that you think others might not like, tell them now and see if it scares them off.

I'm trying to figure some of this out myself as I'm finishing up some campaign ideas before looking for some players myself. I'm interested in what others will say but here are my thoughts so far (admittedly without much experience in finding online players).

I agree with the advice about saying stuff about yourself, or at least about your game. Are you running a dungeon crawl that is mostly combat, or a game about court intrigue that will be mostly roll play, or something in between. That way players will know if they are interested in same kind of game as the one you want to run.

I'd also ask a few open ended questions, meaning questions that don't have a yes/no type answer. So things like, "What's you favorite thing about D&D?" "What annoys you the most in a game session?" "In a couple sentences tell me what sort of character you'd like to play."

I think the character one is important, not because you should be trying to put together some perfect well-balanced party, but because of how people respond. The person who says "I'll play anything the party needs." Might actually just be very helpful, but they are probably telling you what they think you want to hear, and they've already failed to follow directions. Now you may not care about that, but I'd rather know that a player has a cool background in mind, or that they are really interested in a certain ability, or subclass. That tells me a lot more about who the player is.

I think a few important things to address are what tone of fantasy they want to play in D&D. Is it ridiculous comedy, lighthearted adventure, anime-ish craziness, classic heroism, grim reality? How do they feel about character death? Things like that. This can help you cut out players who’ll play different styles of storytelling than you’ll offer, though some will of course be able to adapt. It also can’t hurt to ask them some questions about what they like to do outside of D&D, just get-to-know-you stuff like favorite bands or favorite sports to watch. That should catch out some of the more socially problematic or disruptive people you may not ultimately enjoy playing with.

Quote from NaivaraArnuanna >>

I think a few important things to address are what tone of fantasy they want to play in D&D. Is it ridiculous comedy, lighthearted adventure, anime-ish craziness, classic heroism, grim reality? How do they feel about character death? Things like that. This can help you cut out players who’ll play different styles of storytelling than you’ll offer, though some will of course be able to adapt. It also can’t hurt to ask them some questions about what they like to do outside of D&D, just get-to-know-you stuff like favorite bands or favorite sports to watch. That should catch out some of the more socially problematic or disruptive people you may not ultimately enjoy playing with.

The first part about tone and what kind of stories they are interested in is good advice, and I know I will regret asking this, but how does what sports you watch determine whether you are a socially problematic or disruptive person?

Personally I would avoid questions like that. For one thing, during a pandemic when most of us have lost the option to do many of the other things we like to do, it's kind of a cruel question. After all, what if a persons favorite things to do are go to games, or concerts?

Also you have confirmed one of my life long fears. I always panic when someone asks me what kind of music I like because it makes me feel like my inherent coolness is being judged. I have always told myself that no, people are just curious and they are not determining if I'm worth hanging out with. I suppose the good news is that my irrational fear is now confirmed to be somewhat rational. Some people may have just been making small talk. Some people really were judging me.

I will say it might be worth asking if people like the DM to play background sounds and music, and if so what kind (not all people use fantasy themed stuff). Personally I don't like it for games played over voice chat because it can make it hard to hear other players, but it's great for in person games.

I’m sorry you read my comment that way; that’s not how it was meant. I just meant it’s good to ask some friendly get-to-know-you kinds of questions that don’t have much to do with D&D, because people who are not so friendly and are just there for the game might be put off by that. I don’t care if someone watches sports, what their favorite kind of music is, or even whether they’ve been doing anything during the pandemic except playing video games. I don’t care how “cool” someone is, I left that behind in high school. But sometimes I am concerned about people, especially randoms, being people I’d be comfortable being friends with outside of the game, and seeing how they respond to some friendly small talk is a good way to get a sense of that. I’m sorry if I came across as judgmental, that really wasn’t how I meant it.

Quote from NaivaraArnuanna >>

But sometimes I am concerned about people, especially randoms, being people I’d be comfortable being friends with outside of the game, and seeing how they respond to some friendly small talk is a good way to get a sense of that. I’m sorry if I came across as judgmental, that really wasn’t how I meant it.

Thanks for the apology. Defiantly not something I expected, and I admire you for it. Probably a sign on my part of how high my stress is these days. It does highlight the trouble with finding people on line for a social group like this because it's very easy to misunderstand what someone means while typing an answer.

And to the OP sorry for temporarily hijacking your thread.

Dungeon Dudes gave me 3 questions that have worked incredibly well -- you would not do just these but combine them with the other suggestions here. The questions are:

1. What is your favorite thing to do in D&D?

2. What is something you've never done in D&D but always wanted to do?

3. What is one pet peeve/thing you dislike to experience in a D&D game?

I have found these questions very useful.

#1 tells you what people like... of course my players were all over the place, with answers like "explore and RP" or "RP and combat" or "level up and gain new abilities" -- answers that when you total them up amount to, "the favorite thing my players like to do in D&D is play D&D." But well, that makes live somewhat easier... as long as we're playing D&D they should be happy. But if the answers are a little more focused/less all-encompassing it may tell you what to key in on. For instance, if all your players say they like palace intrigue you know not to give them a straight-up combat-oriented dungeon crawl.

#2 tells you what you should try to reach for -- something cool each of them always wanted to do. Maybe it's mine, "Actually fight a dragon," which I don't think I have ever done (except maybe for a juvenile one) in Dungeons and DRAGONS. (Did it in NWN, but not tabletop). (The reason for this is that we never got to high enough level to make it viable -- we would play to level 3 or 4, and then stop for a while and when we started back up, we'd start at level 1 again.) Maybe it's "Explore the many planes of existence," or "have my character ascend to a  noble or royal head of house." This can tell you long-term where to see if you can take the campaign so they can do the thing they've always wanted to do.

#3 tells you what tropes or themes to avoid. Most of my players didn't really have major hates here, other than "metagaming" or things like that. But maybe someone says, "I hate horror." Stay away from Strahd. Or maybe they say, "I really hate RPing romance." Avoid having NPCs flirt with them. Etc.

These questions also tell what players value about the game, which tells you something about them. A new player entered our campaign and when I asked her what #1, favorite thing, she said, "DMing." Well now, that is awesome for me to know -- if she sticks around (there is a question about whether her 2-year-old is going to make this possible, but so far so good), maybe she will take over in 6 months or a year and I can take a break from DMing. She also said she wants to be in a really long campaign -- well ours is going on a year, so again, if she sticks around, we can oblige. These answers tell me something else about the player, though -- this is someone who loves D&D and who, life and family permitting, is in the hobby for the long haul. That is a very different type of person from someone who says, "I just wanna do some one-shots and kill orcs."

Quote from BioWizard >>

Dungeon Dudes gave me 3 questions that have worked incredibly well -- you would not do just these but combine them with the other suggestions here. The questions are:

1. What is your favorite thing to do in D&D?
2. What is something you've never done in D&D but always wanted to do?
3. What is one pet peeve/thing you dislike to experience in a D&D game?

 I’m not usually a fan of theirs, but I d agree that this was one of the most useful things they did.

I feel like this thread, while posing some good questions (I certainly like BioWizard's offerings), might be a little too focused on the "are you as a player a good fit for my game?" question(s) as opposed to the opposite (and equally important) question of "is my game a good fit for you?".

If you are at a stage where you are interviewing players to potentially join a group, it seems likely that you already have a good idea of what kind of game you'll be running, or what kind of style of game you like to run. I think it's important to consider the fact that, as much as players need a DM to run a game, DMs need players to play in their game. Consider that you are interviewing to be their DM as much as they are interviewing to be your player!

At some point in the conversation - which, by the way, it needs to be an informal conversation; people don't typically enjoy being put on the spot with a barrage of questions - you will need to be frank with what style(s) of game you are comfortable with running. The player shouldn't be trying to "guess" what the "right" answer is. Just tell them what kind of game you want to run, and see if it is something they will be interested in. You don't have to give away spoilers of your campaign, but consider it an "elevator pitch" of your campaign. Describe the overarching concept, where on the sandbox-vs-narrative spectrum it falls, what percentage each pillar of play represents session-to-session, how deadly your game is, and how much responsibility the players will have for driving the action forward in the game. Are the players the drivers of the story, or are they more reactionary to what the villain NPC(s) are doing? I might refrain from pidgeon-holing your game by trying to describe it in terms of what fantasy literature it resembles (I dislike saying a game is "like Skyrim set in the Game of Thrones universe" or something similar); use natural language to describe your setting and game style.

Then give the potential player the opportunity to ask some questions so that they can come to the conclusion of whether it is a good fit for the both of you. This makes them feel more comfortable with potentially talking about games they have played in and enjoyed in the past, and if you hear something that sets off a red flag, you can hone in on it and suss out more information; make sure your game isn't going to be incompatible with what they are saying they have enjoyed in the past, and also that their past game experiences aren't going to be a problem at your table.