Depends on the DM and the arrangment of the start.

In some cases a backstory can help solidify or explain the characters personality. In other cases there isnt really much need of a backstory as the characters are pretty much fresh out the gate.

Personally I prefer to keep it short though. Like one, maybee two or so sentences.

example 1:  Jan has a background of about a paragraph explaining how she trained archery with one of the local woodsmen who also doubled as part of the militia and did not hold it against her that she was a half-orc where others ridiculed her. From that then she sees her character as looking up to professionals who are open minded. But being distrustful of the general populace. Prefers the outdoors over the city.

example 2: "Trained under the local wizard." Character develops as they go.

I like the 5e background system. Neet and simple. Gives you as much as you want to use to flesh out the character before they became an adventurer. Use just the title for an idea, or use the system to generate an idea to frame off of.

Different types of games require different approaches to backstory. In the political/player-driven sandbox campaigns for HarnMaster, where the PCs are very clearly a part of the political landscape, with extended family connections and inherited alliances and rivalries, a character without a backstory wouldn't be playable. This is a setting-based campaign style, and it is almost mandatory to weave the character into the world to make sure that he or she is a true part of it.

The backstory also creates an opportunity for the players to engage in a specific part of the world-building process; they create a part of the setting and make it their own. It is clearly a minor part, but one that might carry significant weight for the player in question. So that can be rewarding as well, as long as the backstory is integrated in the overall setting (which requires the gamemaster to read and use it).

In a different campaign style, more focused on exploration, adventuring and so on, that interconnection between setting and character isn't as important. A brief idea of the character  is enough to get the game started, and eventual blank spaces can easily be filled during game. A minimal backstory is still necessary, but a very brief concept description is usually enough during character creation.

Of course, in both cases, it is strictly recommendable to use some sort of random events or lifepath to generate a few outside inspirations, if only to prevent cookiecutter clone characters.

Quote from: Gabriel2;832488Backstory should inform and support personality.

I'll second this. Obviously our origins shape our personalities.

They also shape our abilities. There are different reasonable inferences about people who grew up in different places and had different careers.

Finally, and perhaps most importantly, the past provides relationships, which are what make personality relevant. Relationships can provide motives and conflicts that produce interesting adventures.

That is a big help in giving a role-playing game momentum. As a gm, I find that NPCs situated in and engaged with more than themselves are a great asset; and this holds for player-characters as well. A "nobody from nowhere" figure doesn't give much on which to build.

Of course its true that a backstory can add to a character's personality.  However, if you create too much backstory you end up with a character that can feel pre-fab, fake and not really vibrant.  In my experience, the real essential key to personality developing in a PC is what you actually do in the first three or four sessions.  A little backstory is good, but what you really want to do is leave some space to see what the PC turns into from the first few sessions of actual fucking roleplay.