In my story, there are quite a lot of characters. It can be difficult for me to give them dialogue. For example, let's say that there are a five friends at a party. I would run into a habit of having only two of the characters speak. Is there a way I can distribute dialogue when there is a lot of characters?
Dialogue, just like everything else in a well-written story, has a purpose: either to advance the overall plot or to develop the characters. Who speaks and says what in what scene depends on what needs to be said and who the focus is on. Even if you want to develop all 5 characters, it doesn't necessarily have to happen all at once for everyone in every scene, even when all of them are present. Perhaps Tim and Sally are the focus of the current plot point/character development, so even if Harry, Shawn, and Linda are also at the same house party, they say comparatively little that is actually told the reader, because they are off chatting with one another about plot-unimportant things while Tim and Sally sit in the corner together and discuss their recently deceased friend Roger.
That said, when you have five characters in a room together, you don't want any of them to "disappear" either. It occurs to me you may really be asking about how to avoid this phenomenon: the vanishing of characters (and it can happen to your setting as well!) when the writing doesn't keep the reader present enough in the space the scene occurs in. Usually this is because the dialogue/focus is so caught up in whatever the main thought the writer is trying to get across that it forgets to include descriptions, sensory details, etc. about what is around the characters at that time.
I remember when I wrote a story in college, two characters were having a serious conversation in the backseat of a car, and my professor asked me, "Where did the car go?" Essentially, I was so focused on the characters' reactions and dialogue that it was all you could see from what I had written. They might as well have been sitting at a cafe, or in a movie theater, or anywhere else, because there was very little to remind the reader of where they actually were for the whole passage.
This happens with other characters in a setting too, if you aren't careful. Tim and Sally are talking, and pretty soon you realize, "Hey, where did Linda, Shawn, and Harry get to? They were in the room as well, but we've heard nor seen nothing from them for three paragraphs now!"
The solution to this problem isn't necessarily to just give the others more dialogue, but rather to ensure the entire setting, them included, isn't left behind. Sure, maybe one of the others says something from time to time. They might break into the conversation to make themselves know, like here, where Linda just arrived:
"Sally, I think that..." Tim paused as Linda appeared next to Sally's chair.
"I haven't had a chance to ask how you're doing," she said.
Sally offered her a half smile. "I'm okay. Thanks for asking."
"I'm glad you're hanging in there, girl. Nice to see you as well, Tim." He nodded.
"Hey, Linda! Come help me with this pizza!" Shawn called from the kitchen, and Linda gave Sally one more reassuring smile before she turned away.
More often, though, I think you'll find action and sensory input from by the other characters sufficient and less disruptive for any given scene:
Tim paused and glanced to the side as a clatter echoed across the room. Shawn had dropped the punch bowl and was now swearing as he looked down at his wet pants and shoes. Clumsy as always. Tim and Sally shared a smile.
Linda's laughter carried across the room, at odds with the grim expression on Tim's face, and Sally sighed. "I don't know, Tim. I thought I could get answers, but all I've found is more questions."
Tim raised his voice to be heard over Shawn and Harry's roughhousing behind them. "I don't know what to think anymore, Sally. Nothing seems to add up like it should."
"I know." She leaned forward slightly so he could hear her and spoke low, "I'm starting to think his death wasn't an accident at all."
Someone bumped into her chair and she startled, glancing back to see Shawn's sheepish grin. "Sorry," he said, then bounded back across the room toward Harry, whooping.
Hmm, I think I have the making of a very cheesy murder mystery / possible romance novel here XD XD
One final point: At various point in your novel, assuming all five characters are meant to be important, each of the characters should have scenes where they have more dialogue and "moments" that help develop them. If you notice that there is one character who is always just kind of "there", standing around while everyone else talks and does things and comes up with the plans, then this character is currently just window dressing, and you need to take a good look at them. You need to ask if they have a real role to play in the story, and if so, why aren't they filling it? Perhaps another character is already filling the role you meant them to fill. Perhaps you don't actually need this character at all and should cut them entirely.
I once had a character whom I just couldn't get to come into their own, and I eventually realized that it was because their role in the story overlapped too much with the roles of two of my other characters, who each had a more interesting base personality and background, and had each therefore become the character who "dominated" their position in the story. I fixed this by removing the neglected character from the primary plot and placing them in a separate situation on their own, which allowed them show off their strengths and flaws out from under the others' shadows, while their absence simultaneously created a conflict for the other characters.
Side note: love interests, in particular (especially female ones), often suffer from the "cardboard cutout person" phenomenon, where they have no active role other than to exist as eye-candy for the main character to drool over. They stand around and look hot while the other characters do everything. If you want to have a love interest, you need to find a plot-relevant active role for them to play and develop the character to have their own personality, motives, and flaws. It will instantly improve the character and your story, I promise.
You Can Lead a Horse To Water:
But that doesn't make him Mr. Ed. Characters take on a life of their own, and there's no external rule to make them talk more. It sounds like you're conflicted about if characters should be talking more or not. On one hand, you admit you DON'T have them talking, and it doesn't always make sense for them to, but on the other hand, you want a rule to give fair speech to all.
- Don't be afraid to have major and minor characters. If some talk more, they are bigger characters. Simple.
- If you want it to be equitable, then write the story so each character has parts where they are major characters. Have a chapter centered around each, and make sure the events focus on them so they get developed. Or establish their relationships by how much time they talk.
- Don't be afraid to use internal dialogue as a substitute. A character can be an informal narrator, listening to others talk while reflecting on the conversation. This also gives you the chance to introduce some limited omniscience to the story. Dick and Jane fight about Spot, but Joe knows Spot didn't pee on the carpet, and stays silent because it was his dog Rover who did.
- Are all of your characters present all the time? If the dialog seems out of balance, people go off on side-quests for the story while the rest talk and reflect.
- Actions are as important as words, so you can have characters shine by what they do, not what they say. Some of the best characters almost never talk, but provide an example.
Ultimately, if you want characters to have more say, you have them talk about what's important to them. If that's not important to the story, they don't need to be the center of attention. Stress less and let dialog evolve naturally. I find I don't need to try with dialog. The characters get to have a voice, and start saying what they want to. The story may move in an unexpected direction, but that's creativity. If you need to have things go a certain way, that's your executive privilege.
Do not give them dialogue for the sake of giving them dialogue.
If it would be logical for other characters to speak more, then give them dialogue. Otherwise, you may want to just throw in an observation that the other three were talking about something while these two talked, or the other three were listening intently, or whatever.
I run into the exact same problem all the time. In my fantasy series, there are six main characters, not counting the antagonists. If I did count the (main) antagonists, there would be eight main characters. A lot. Sometimes when all my main characters are together, their conversations sound either too choppy or too planned, like they’re not even the ones talking. One way I fixed this is giving each of my main characters extremely distinct voices.
Example: one character has an accent.
Another character uses a lot of slang.
Another character is very formal.
Another character is always sarcastic and jokes around.
One character talks like me.
And my last character also talks like me because he happens to be the MC’s brother.
So if you have different voices for each of your characters, you will not have to use dialogue tags unless necessary, and your dialogue will seem less choppy.
Another way I fixed this is (if you haven’t already) getting to know my characters as actual people, not just figments of your imagination. Put your characters with the other characters and see what happens. Put them in difficult situations and see how they react. Get to know where they live, and how the people that live there talk. Do your research. A book without the proper research sucks.
I recently read a book that took place in London. The main characters were from London, their parents were from London, and they talked like they were from America. They’re names sounded like they were from India. It was extremely frustrating, so I just stopped reading the book.
Research is key. Weather your research your characters, dialogue, setting, names, accents, cause and effect, whatever.
(P.S. this site is great for research on how to write. I use it all the time.)