Writing unaffixed dialogue with more than two characters works in principle by the same consistent alternation method with self-identified speakers:
Standard:
“Blah,” said Joe.
“Blah, blah?” asked Jill.
“Blah, blah, blah.” (Joe again)
“Blah, blah, blah, blah.” (Jill again)
Etc.
Until shortly the reader loses track of who is speaking. And the author reassigns dialog tags. The primary reason a reader will lose track is the lack of distinction of “voice” of the two speakers. In genre fiction written only for entertainment value, extended dialogue without (omniscient narrated) action is rare, and thus identification tagging occurs through associated action.
“Blah,” Joe said as he hit Bob.
Jill put herself between Joe and Bob. “Blah, blah?”
In Examination of Serious Coincidence Through Dialogue with the Dark Prevailer, part 23
https://www.thenextbigwriter.com/postin … t-22-25545
all action is narrated through one of four characters, Amanda, and as such presents like a first-person narrated story. The exception to this sort of narration is that Amanda does not act in a quasi-omniscient narrator identifying who-says-what. Identification is presented through dialogue itself and maintained by the distinct voices of the particular characters: Amanda, the storyteller, and Claire, a woman of few words acting in capacity of sounding board.
In addition to the two principal characters are Chaz, distinguished by his words included in quotation marks, and the unidentified Dark Prevailer of the title -- in italics. Only the DP’s nature and purpose in the story is ambiguous to the reader, and that is his purpose in the story. The italics could mean Amanda’s internal monologue, could mean an internal dialogue (hallucination or dream fragment), could mean a supernatural entity (a known unknown), could mean a natural, but not understood, entity (an unknown known), or magical entity (an unknown unknown). In this case, and for any author who wants to use a punctuation device like italics, one is hampered -- corralled into pseudo-convention-- by the meme of italicizing internal monologue for which there is already a standard device of quotes with “she thought” tagging.
Next: distinction by voices of characters.