I'm curious where the rest of you DM's tend to draw the line between in-game observations and OOC info? For example, I have a player in my group who is laser-focused on combat mechanics, and generally assumes that every die rolled in combat should be unambiguously identified to players along with its associated game mechanic. Here's a fictitious-but-typical exchange from our table:
- Me: "The bandit archer stands up from behind the barrel. He points his finger directly at <PC-1> and mutters something before drawing back his bow and firing."
- Roll 1d20 => 17 "He hits!"
- Roll 1d8+1 (arrow damage + DEX bonus) => 2+1
- Roll 1d6 (Hunter's Mark) => 3
- Me: "<PC-1> takes 6 points of piercing damage."
- Player5: "Wait, how is that 6 points? Why did you roll another die? Is he a rogue? <PC-1> isn't flanked, so there shouldn't be sneak attack damage."
- Me: "Right, <PC-1> isn't flanked. It looked like that shot was extremely well-placed, though. <PC-1> takes 6 points of piercing damage."
- Player5: "It's all piercing damage? So it's not an elemental buff. Is he a Ranger? Oh, <PC-1> was already wounded, is it extra damage from Colossus Slayer? Isn't that a d8? Wait, did you roll a d6 or a d8?"
- Me: "You did notice him doing something right before he fired. Does anyone want to make an Arcana check?"
- Player5: "Why should I have to roll Arcana? Clearly he took more damage. We should know where it came from, we all saw what happened."
You get the idea. Obviously we have different ideas about how transparent the game mechanics are to in-game characters. To him, we're playing a wargame with certain rules and there's a bias towards "perfect information" so players can adapt to the strengths/weaknesses of the pieces in play. To me, there's no reason the characters would automatically have that information. As far as the characters are concerned, that bad guy did something, maybe you recognize what happened, maybe you don't.
We've had OOC discussions about this a couple of times outside of session, and it's not like those have been hugely adversarial . But every time I think I've explained how I want to run the game, it crops up in some very slightly different context. Like, we put the issue of bonus damage dice to rest, but then when an NPC has Haste up and takes an extra action, there's a five-minute holdup at the table ("That's two actions!! He can't take disengage as a bonus action unless he has cunning action or something, so he wouldn't be able to attack.") and we're back to square one.
I know there's no silver bullet that will put this all to rest, but this constant back-and-forth has got me curious about what is the "most common" way of handling this stuff? Just wondering if I'm out on the fringes here, or more near the median. ;-)