Long Rest Cost

[Sinara]

I noticed that time passes while you go do a long rest. Does that mean the in-game time passes as well in the sense of like the world around you? In other words, to give an example, there was a quest in the first part of the game where you can either save a girl from a harpy or not, and if you do certain quests you can find her corpse where the harpy are meaning you missed your chance to save her.

If I pass time with a long rest will that mean that I didn't get the chance to save her or does it not matter and it doesn't effect the world?

[hermit0wl]

Pretty sure Mirkon is a boy :)
There's a handful of quests/situations that, once you run into them, will progress on a long rest if not dealt with. Basically, it happens whenever you see someone in immediate danger, or in a couple cases later on you're explicitly told that something will happen "tomorrow" or "in three days".
Otherwise, no, the world state won't change no matter how much you rest.

[Mongooses]

Only quests/areas that have been triggered will progress with long rests.
Like you said with the tiefling kid and the harpies.

There are a bunch of quests, events, etc. throughout the game that will progress by resting, but only once triggered.

For instance if you take 40 long rests before going into the harpy zone, the kid will be safe. But as soon as you enter the area the "rest timer" starts for the events in that area.

This caught me big time in one area much later in act 1. Basically went to a totally new area. I wasn't finished exploring the previous area so I went back, had to do a bunch of stuff. By time I returned to the new area I had wandered into bascially all the NPCs had left and a whole bunch of stuff had progressed that I didn't see.

Basically you kinda need to explore whole areas at a time, try not to rest too much in those areas and then rest before progressing to another area.

Also long resting is important to progress companion story lines and such so just avoiding resting will prevent other stuff from happening. Need to find a balance.

Don't be overly concerned though. Still lots of content in the game, more than your going to see in 1 playthrough, so if you miss some stuff it'll be new for the next one =p

Also it's not always just 1 rest that will progress things. The area that I mentioned (keeping vague so no spoilers) allows 1 rest. But if you take a 2nd long rest after activating the area then stuff progresses.

[Wolfherz]

Heh, I learned that the hard way in the Grymforge area. It made me so mad I actually completely restarted since I didn't have a save that took me back far enough to undo the damage.

[TaKo]

very few quests are 'time-sensitive' and the ones that are are usually obvious about it if you triggered them or got close enough to their trigger zone, theres a wiki page dedicated to this content in the bg3 wiki but obviously beware spoilers

[CyrusWindstrider]

One of the most ♥♥♥♥♥♥♥♥ things I encountered very recently is this-- if you go to the mountain pass with Lae'zel in your party, she leaves to go run down to talk to the gith there, and you think "oh cool, I'll just pop into camp for HALF A SECOND to bring someone else just in case" it counts her as dying instantly. Just a heads up because it's completely arbitrary-- you can stand outside of the conversation as long as you like, but as soon as you look away, bam, dead.

And no, I didn't take a long rest, literally just went to fetch Wyll.

[Annie Other]

Long Rest does not affect saving Mirkon. It's a location trigger here. The game autosaves, then you get a quest "Investigate the Beach". Once this quests appears, you best do this next, otherwise you fail your chance to save Mirkon.
I had a Long Rest before going there and still was able to save Mirkon.

Saving Nadira is much meaner.. There is a location trigger somewhere, and once you are within range you have to run to her location or she'll be dead. Even when you are coming from the "wrong" direction she'll be dead. But as long as you are not within a certain range, nothing happens.