If they want to go and check they can tell me how long they're going to wait before doing so. For example if the scout's not expected back for an hour but they're going to start worrying after only half an hour, then at the half-hour point I'll check and find out what they're doing.
It does, provided that - both in and out of character - people are willing to commit to doing what they say they're going to do.
If I ask what your character's doing for the hour the scout expects to be gone and you say your character's just going to wait for her to return, that's your action declaration and you're committed to it unless something interrupts you e.g. a wandering monster or a scream in the distance or whatever.
Which means that if after the hour I come back and ask "What next?" and you say "Well, after half an hour I would have..." I'm completely within my rights to shut you down right there for two reasons: one, you now know nothing happens in the full hour and two, you already committed yourself to doing nothing for that time.
And if you want to go to where people aren't committed to their action declarations once they've been made, we've got bigger and likely unsolvable problems.
So people in your world cannot change their mind mid-task? Hunches only come up at pre-determined times?
Doesn't sound very verisimilitudinous at all.
That dragons often have some sort of breath effect is fairly common knowledge if only due to all the stories told about them. Which dragons breathe what, or how big an area it covers, or any other fine details likely aren't learned by a party until they've faced a dragon or two and figured out how the things work.
That, and in the right situations some dragons' breath effects are pretty easy to telegraph through char marks on walls, acid pitting on stumps and logs, and so forth.
About the only thing a neophyte character would almost certainly know for sure is that standing in front of a dragon is probably riskier than standing behind one.
As luck would have it, they just took out a big ol' Blue in my game. They knew from numerous sources going in that it breathed lightning but had no idea what else it had going for it other than size, toughness, and a fearsome reputation built up over decades if not centuries; but they had circumstantial-evidence level reason to believe (correctly, as it turned out - long story) that it might be getting weaker rather than stronger as it aged. Once they met it they found it hadn't lost a thing on its lightning breath but its melee ability was nowhere near what it once was, and it could barely fly any more. Even then, it still knocked off two characters out of five in a real edge-of-the-seat combat.
Why is breath weapon "fairly common knowledge"? Has that been decided in some way ahead of time? Has it already been established?
This is my point... why require that players pretend to not know what they know when it comes to this stuff? It actively highlights the metagame aspect rather than avoiding it.
If someone in my game said "Disperse, don't group up!" I'd assume they'd heard about a dragon's breath weapon, or otherwise intuited the risk, and we'd move on without any disruption at all.
Burning Hands goes 15 feet these days?
In my game it only goes three, meaning that to cast it on a Troll you're going to be well within its reach.
Good luck with that. Please make sure your Wizard's will is up to date before attempting.
Oh I play my wizard in a risky way all the time. He's perfectly effective and what's more, it's fun to play.
Not that this is related to the actual topic, but this is just another "there are ways these things are supposed to work" example that I think is related to the larger issue which, as the thread goes on, seems more and more about control than anything else.
Interesting example, because they just met some Aarakocra recently in my game and had no clue what they were (which makes sense in one regard at least: I'm not sure if I've ever DMed any before now). I just called them "Flying People" or "Birdmen" or something similar, because that's what they looked like to the PCs. They weren't an obvious threat and could fairly easily be bypassed, so the PCs more or less left them be and kept going.
And nothing would have been different if one of the players was familiar with arakocra.