asks: I was wondering on how to manage a story with a large cast of characters (and when I mean large, I mean over 10). As the author, I myself am familiar with these characters, but I'm worried the reader would be confused and lost, because there are a lot of them in the same place at the same time. Other than trying to make them distinctive (because I think they are in terms of personality), how should I go about writing them when some take up way more screen time than others? Keep in mind, a lot of them are minor/secondary characters.

It's okay to have a lot of characters, but bear in mind that not all of them deserve the spotlight. All those characters in the scene actually don't need to be distinctive. The story has to revolve around the main characters, and the side characters are just there to help the story along. Because of this, we don't need to know everyone's background. The reader needs just enough to understand why they behave the way they do.

In any scene, even a scene with lots of people in it, only a few will take up actual "screen time". Think of movies where you have lots of characters gathered. Only a few will be outspoken to drive the scene forward. When you have everyone talking and offering opinions, it gets confusing and chaotic. Limit it to maybe three or four voices.

This doesn't mean you have to ignore everyone else in the room. They're there for a reason, but don't necessarily need to be part of the action. A little sentence here and there to remind the reader that they're there is often all we need. Here are some examples of side characters doing something small to establish their presence, but without taking the spotlight away from the actively speaking characters:

The team nodded in agreement.

Noah and Jake exchanged glances but said nothing.

Wanda crossed her arms at the suggestion.

The rest of the warriors began laughing.

I tried not to look at the grim faces around me, but their frowns were hard to ignore.

Jane snorted, before schooling her features. "Oh. Sorry."

As mentioned before, not everyone needs to have a detailed background. You, as the author, can know what it is, of course, but it's just clutter for the reader if it doesn't help advance the story forward. For example, Dwight is a dwarf who grew up with a demanding father who expected him to be a top-notch blacksmith just like him, but Dwight has never been interested in the smithy. He likes horses even though dwarves are supposed to hate horseback riding. His friends think he's weird. He makes waffles and likes to eat out in the pasture where he can watch the horses run free. He wants to run free too. He wants longer legs so he can run and climb onto horses without a stool. But he's an optimist, so he makes himself a handy stepping stool to climb onto horses with. He volunteers at the local stables and learns how to handle horses. That's how he meets the hero of the story. (Let's call him Hiro. :D )

So we have all this background on Dwight, but the reader doesn't need to know all that. Up until Hiro meets Dwight, the story has been all about Hiro and his quest. The reader won't really care about Dwight's demanding father or the waffles. The only relevant part is Dwight's unusual love for horses, and how he comes to join the team. Pieces of his backstory can come out now and then, like when they're all chatting around a campfire or something, but he should never step forward and deliver a soliloquy about his upbringing just to feed the reader his unnecessary backstory. When Hiro is discussing battle plans with his team, Dwight isn't really a strategist, so he mostly listens. He can be shown as brushing one of the horses while the others talk. His role is small in this scene, so he shouldn't hog any of the spotlight.

Some side characters can have speaking roles in some scenes and remain quiet in others. This way readers can gradually get to know all the characters. It's more orderly than trying to show each distinct personality clambering for attention in every scene.