So when you have a group arguing it usually goes something like this: "I am saying my point whe-" (new character) "-I have interrupted and cut off your dialogue!" But what if that is not the case? What if it is more of a situation like in ticket master where both sides continue to speak at the same time? Do we as writers simply tone them out and steal potential details? If this were live you could in theory focus on one speaker and hear what any individual were to say but never all of them at once.

This situation seems to just be avoided by most of the fanfics I read perhaps due to this problem despite it happening very often in real life.

I don't really know that's a good question to ask actually.

821363

Usually if you want to get across the dialogue as a mess, you don't put any statement on who's speaking. Several lines of dialogue in a row in a group speaking setting will confuse a reader on who's who, in a way informing them that the conversation's a mess.

821363
This is an interesting dilemma... how about dividing the screen and having both sides of the arguments side-by-side?

I've written two arguments in fics that involved the characters screaming over each other. I made it clear in the descriptive prose that all characters were talking at once and then alternated the dialogue with no additional prose between characters so it was clear who was talking (both tirades were interrupted at least once with a quick prose snippet to reset the stage and keep who was saying what clear). It's not necessarily the best solution, especially because in an actual situation like that you'd end up losing a lot of what's said since everyone is saying everything at once, but I reasoned clarity was more important than strict realism in that situation.

The easiest way is just to say everyone is talking so loudly you can't understand what they're saying.

But if you actually want to show this, I would say show the argument from a single persons perspective. Take Twilight in Ticket Master, she would be hearing her friends arguing but only understand little bits of it. I imagine it would look something like this:

Twilights friends all began shouting at each other, so loudly Twilight couldn't hear half of what they were saying.
"—but the Wonderbolts are gonna be there—"
"—um, if I could just say something real fast—"
"—oh, man, Mrs. Cake made me eat oatmeal this morning—"
"—that money would really help my family—"
"—this could be my one shot at true love—"

At least, that's how I would attempt it, and even then it isn't perfect.

This is one of those issues where I feel that you do have to bow to the limitations of the medium and sacrifice some realism. I've seen a few books trying to show two people talking over each other, but they always feel a bit clunky. It can be hard to convince your brain that the various bits of speech are supposed to be spoken at the same time when you read it.

If you just want to show that they are talking over each other and the actual things they say are unimportant you could just say that they are in narration i.e. show a third character's point of view as they watch the arguing pair in exasperation. Some details could potentially be highlighted in this case.

I would personally try to avoid it in direct dialogue, though. Having them constantly interrupting each other is a possible alternative.

821378
A good idea. So just swap characters every sentence then?
821385
It would be interesting to see but I think that it might not work due to formatting to the screen for different screens sizes

Would it be bad to just step back to script writing to ignore the problem like this: (character 1 in counterpoint) "Everything I have to say" (character 2 in counterpoint) "Something else but still everything I have to say."

There's also the 'Step back' strategy. [From there the conversation descended rapidly into a shouting match, interspersed with threats of not-so-random violence and personal insults. As Twilight watched her friends tear into each other, she was also torn. On the one hoof, they were finally talking, or more accuratly screamiing about problems that had been bothering their relationship for months. On the other hoof, the kitchen in which the arguement was taking place had entirely too many sharp and blunt objects conveniently nearby in the event the arguement turned into a full-blown fight...]

While I think 821398 solution would be funnier; I think 821406 has the right idea. It would be less confusing for the reader to just describe the entirety of the situation in the narrative. It would at least look tidy, and neat on paper, and the reader wouldn't be asking who said what when. However, if your goal is to in fact confuse the reader, and make them wonder whose line was spoken; the former example is your best route.

-And then I said, 'Oatmeal? Are you crazy?!'

I know I'm resurrecting an old thread here, and what I'm going to suggest goes completely beyond any standard writing conventions, but what if you did something like this:

Twilight stared at the rest of her fellow Elements of Harmony.
"But how are we going to deal with that giant Ursa Major?" She asked them.
"PartypartypartypartyPARTY!" "We'll need to round up more help to take on something that big." "I have a plan, it's shock and awe! I bring on the shock, and he'll go AWWW!" "I really don't know, but that coat of his is simply divine!" "Didn't you face its baby before? Maybe she's looking for her child?" Pinkie, Applejack, Rainbow Dash, Rarity, and Fluttershy respectively replied all at the same time.

821970
I've done that to some people IRL before,
I quietly lol'ed to myself