My first TPK in a while

[Rynjin]

But it all boils down to choice. The party could have used Leomund's tiny hut to camp in the dungeon and take a long rest but they didn't. So the question is should I have taken into consideration that the party didn't take a long rest and decided that the villain doesn't act on the information about the party where abouts because of that, and if I did would that then be considered a "Dm's Fiat"?

The mentor and the friend of the party that were waiting outside the dungeon, should they just have vanished? I gave them a 50/50 to be captured or not by the villain and even allowed the players to roll for it so that was that.

This GMing style always frustrates me, because these two paragraphs are actively contradictory.

On the one hand, verisimilitude. Two NPCs are left unattended, and the villain arrives. He kidnaps them. This is fine.

On the other hand...game logic. The party TOTALLY has the option to spend 8-12 hours resting, during which the villain will of course...do nothing? He'll just let them pull back into the tunnels, let them rest, and then stand in the same position until they get back and are ready to tussle again? This is also fine, on its own.

The issue is when these two ideals clash, as here. Either you're playing by video game logic or you're not. Sending mixed signals means the players don't have the information they need to MAKE an informed decision. Because the mindset of the GM and the style of the game is one of the most important things when it comes to making the right choice in a given situation. Players can be Wrong Genre Savvy and it leads to issues. As it does here.

What you have essentially told the players is one thing: events in the world continue to move in the background even when you can't see them. This implies that given 8-12 hours to prepare, the villain will do...something. Torture the hostages for information. Set up an unwinnable fight in some way, such as by laying traps around their Tiny Hut. Maybe just...**** off back to his lair with the hostages and leave a note saying "Come see me when you're willing to negotiate."

But what's actually happening is that they should actually ignore all those potential consequences of taking a rest, because events only move in the background on your whims, not by any sort of logic.