Very good so far, but the unfortunate side effect of D&D ruleset is that almost nothing is deterministic, especially when it comes to conversations.
You can pack crazy Charisma and proficiency in Deception/Persuasion or whatever other skills and you blow up conversations right and left because of that frikkin' dice, this is especially frustrating because a lot of insight, information and more interesting developments are gated by these checks and at time multiple of them, so you are pretty much compelled to save scum, if you want a more interesting story.
Many other checks that are not conversation allow 4 rolls for every team mate, so at least there you have a more reasonable shot at finding that secret entrance/button/lever/whatever, but conversations are a one shot chance and the check requirements are really stacked against you in vast majority of them - talking about something like 50% chance of success for your character that packs +3 Charisma modifier and +2 proficiency on conversation skills. I can't imagine what your run off the mill fighter/wizard/cleric with +0 Cha at best would look like - you'd be like missing 70% of the interesting stuff in convos, no kidding.
I really hope they will relax the required DC for those a tad, pretty ridiculous imo.
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Like this is on my level 3 warlock now:
You'd think I'd be some master silver tongue navigating my way through conversations, but nope - any moment conversation is not some basic mundane stuff and it's a huge uphill battle of minds, even with those stats, which are really as good as it gets for conversations at that level. Like, maybe I could precast "Friends" on just about every bloody NPC I meet, but that's about all I could do more there and it would just give another +2 or so.
Some places having a difficult conversation DC is as it should be, like persuading Shadowheart to spill her beans on who she is in the Blighted Village. That one you can't do without +3 Charisma with Persuasion proficiency, it's like 22 DC persuasion there. But that's OK, she's almost committing a sacrilege against her faith as a cleric there revealing that info in that fashion.
But having a bloody 17 base DC or some such on holding 2 blokes from hitting each other and having a bloody fight where you may need to kill people if you fail that check instead of letting them to just slap each other, that's just ridiculous.