As a DM, I think it’s crucial that players in a long term campaign have a well thought out backstory. Backstories are important: they give a player a sense of where they come from, and how they will react to future events. They give them things to care about, or fear, or hate. They establish relationships with people, living or dead, and can provide motivation. When you are running a campaign, it’s your job to help your players come up with a backstory, and to incorporate the details of that backstory into your campaign.
If it sounds like a lot of work, it is! Some players effortlessly come up with 10 pages of highly detailed backstory, giving you the names of everything from the country they came from to the name of the midwife that first wiped their bottom. Most people won’t be that detailed though. Odds are they have a sketchy idea of what they want their past to be, with varying levels of detail and names. Without creating a backstory for them, you want to work with them to expand that backstory, and help connect to the world you will be running.
I think the easiest way to help someone create a backstory is to give them a list of questions about relationships and past that they have to fill out. Mine looks like this:
Where were you born? (specific or generic)
How did you grow up? (poor, homeless, noble, convent,etc)
Are you parents still alive?
Do you have any friends/lovers/mentors still living?
If so, where/what are they doing?
How old are you now?
How long have you been traveling from your birthplace?
Where do you consider “home”?
Has anything significant happened to you in your travels?
Is there any major event, meeting, or trauma that has shaped who you are?
Is there a specific story behind the acquisition of a skill or item? (i.e. my father gave me this sword, i had an affair with a royal courtesan who taught me to pick locks, i saved the life of an elf who taught me elvish, etc.)
How and why did you come to [the start of the campaign]?
They’re basic questions, and can be answered as specifically or as vaguely as the player desires (or has energy for). For some people, this might spark their creativity and they’ll be able to create detailed responses to the questions. Other people might still struggle with really coming up with a story.
It’s between the DM and the Player how much help the DM wants to give the player in creating their story. I personally think it’s very important to incorporate as much of a character’s backstory into your world as you can, so I want my players to have details I can use: places, people, events, items. Part of my passion as a DM is world building, so If a player is struggling and wants the help, I will extrapolate their vague answers into specific people, locations, and detailed stories. This dynamic does not work for everyone though, and you should base how you handle backstory on your own inclinations and the dynamic between you and your players individually.
If you are running a one shot, you obviously don’t need to have that level of attention to backstory. If a player does have a backstory to go with their character, great! It will help them as a role player, and it might give you a detail you can throw into the game. But it’s also fine if the players haven’t put any thought into the history of their newly made persona: after all, they’re only going to be playing them for one game.
What I think you SHOULD do for a one shot is establish a relationship between the players. The timing of a one shot game is tricky, and you don’t want to waste the first third of your game having them meet each other in an inn. Have them be an existing party, and give them a vague hint of their last successful (or failed) job. If you do want the rp of meeting to occur, have a couple people establish relationships based on their background, similar skills, or player ideas. Some examples would be:
Two people took the Soldier background (5e), so have them have served together
One of the players is bard, so have one or two of the other players be a fan
A player decided for humor that they have 3 skill points in craft macaroni art. Have another player be a collector of macaroni art.
Another good way to draw people into the world of a one shot is to give each player a piece of crucial information or helpful connection within the world. Maybe it’s the combination to a magical lock, of a brother in the guard who can look the other way, or a map of the pertinent area; just something they can use to advance the game and incorporate as part of their character.
If it seems unfair to burden yourself as DM with the work of helping people with their backstories, consider this. It’s your job as DM to make sure the players are engaged, and one of the easiest ways to do that is to bring in details from their pasts. The more you put into your game, the more they, and you, will get out of it. After all, if you think that being a DM is something you can do while avoiding a lot of work…you might be on the wrong side of the gaming table.