I'm hopeful we'll be able to have each character try once (for four attempts total + any inspiration dice). For Example, Tav didn't persuade to save Arabella, Gale tried and got a stern look, and then Wyll speaks up and saves Arabella. IRL some of the excitement at the table is seeing which characters succeed/fail in the skill check and how the DM can use that for future conversation between the NPC and party.
Larian can have some situations be "one-mistake-fail" (for NPCs that are stubborn) but every dialogue option being "one-mistake-fail" feels very un-D&D.
4 tries is a bit much imo. Typically I run/play games where players, in dialogue, effectively use the "Help" action to grant advantage to a single character.
If each of the 4 party members can make the same check, then statistically every check will be passed. The expected result for 4-d20-rolls-take-highest is like 16+.
I'd be in more favor of this if the DC went up after every failure. e.g.:
first character gets a DC 15 check
second character gets a DC 17
third DC 19
fourth DC 21
It makes sense that a failed check would make subsequent checks more difficult. Similarly, this would open up systems where successive checks could be made easier through each character passing a check and really provide a sense of teamwork in convincing an NPC. However, this would require Larian to write and voice ~4x the amount of check-dependent dialogue, as I'd want the NPC to respond after each failed check.
Failing ^, I vote for max 2 tries or one at advantage, assuming another character speaks up to help. And of course we should be able to choose which character(s) respond.
