If your group enjoys writing detailed backstories for their characters, well... your a lucky, lucky dungeon master. Don't take it for granted! Use those backstories! Personal Plot, aka character-specific plot, can lead games in interesting directions, give individual players the spotlight for certain scenes, and develop connections between your characters and the overarching plotline.
Choosing to incorporate personal plot in your game has both pros and cons, so your should make the decision about whether or not you use it based on your group and what you think they would enjoy!
Personal Plot Pros
Delving into a characters backstories can add a lot of things to your game. First and foremost it will make the player of the character in question happy that you took the time to work their backstory into the campaign, and will craft encounters of particular enjoyment to that player since their character gets to shine in the spotlight.
Personal plot, if used well, can provide plot hooks for characters based on their past, or NPCs from their past, encouraging them to continue on their quest. Such plot can also be used to develop plot twists, and to connect PCs in strange, sometimes unexpected ways to the overarching plot.
Dungeon Masters should remember that most character backstories hold the reason why PCs began adventuring in the first place. Ensuring that their adventures continue to fulfill these reasons, you can usually keep your party entertained.
Personal Plot Cons
The main reason personal plot can go badly is the very reason that makes it great - it singles out a player. While this can be great for the player, whenever you give one character the spotlight you make every other player take a backseat in the action.
This can be fine, when used in doses. If however you've got a game with six players, and you give one player a significant, extensive, and tons-o'-fun personal plot encounter, your other players will expect that they'll be receiving the same treatment - as it's only fair.
Essentially, you should make sure you think ahead to the amount of time you might be committing to personal plot. If you wind up having a few session's worth strictly of personal plot that don't really do much to advance the story, players can become bored and feel detached from the game.
A good way to avoid that downside is to ensure that even personal plot involves the entire party in some way. Another good technique is to have individual sessions for players to swing by and have a one-on-one game with you for an hour or so to play out some personal plot.
Ensuring that each player gets a chance to shine equally in the spot light during your campaign is important, but just make sure you don't overdo things and have your entire campaign be spotlights. The whole party taking the spotlight together should make up the majority of every campaign, or your players may become competitive with each other - something you want to avoid, trust me. The more plot where the party works together and relies on each other, the better.
4 hours ago