The crown completely disintegrates, as it was rust all the way through

Sorry, Mario, the real crown is in another dungeon.

I once fast-forwarded a complex plot through a GM-sanctioned bit of fluff.

The party had been invited by their uncle who turned out to be recently murdered when they arrived. Of course they investigated. At one point I had my character wrote a letter to the rest of the family to inform them of what was going on. I actually produced the letter as a handout. Since I had no idea about the date I asked the GM and he told me to pick anything in summer.

The GM s happy with the handout and it was deemed canonical.

A few sessions later he noticed that I had picked something ahead the end of the summer and the bad guys' plot was about to kick off at a specific date right after summer ends. So suddenly the adventure went from "careful slow-burn investigation" to "mad rush to the location of the finale".

Oops.

Couldn't they have gone the other route and made the villain's plans a year later? But sounds like it was a lot of fun the way it was run!

The idea was to have some kind of urgency but only once the players were far enough to understand the basics of what was going on. To that end, the date was supposed to be vague so that the GM was free to say "you figured out that the ritual will happen right after summer ends – which is in less than a week".

Then he forgot that the timeframe was vague when I wrote the letter and told me to pick a date.

Unfortunately, this cut out a side plot where our party would've hired another party to hunt down some artifact. That artifact retroactively got downgraded to a red herring for time reasons.

On the other hand, we got an absolutely precious scene where the one party member who wasn't magic-affine and didn't want to be involved with any supernatural stuff had to ride an unnaturally fast six-legged half-demon horse in order to catch up with the bad guys.

Also, it cut down on all the "three wizards and a vintner have breakfast and discuss the state of the investigation" episodes. We had a lot of those.

Rollercoaster are fun yet have rails.

Are you even a GM to allow yourself such snap judgment? But for you know, we GM/DMs are not your employees RPGs are a group collaboration.

How is this in any way railroading?

the real crown was the XP we collected along the way

Retconing things to protect muh precious twists is not compelling, though, it's just base metagaming. The unwavering plot is the GM equivalent of the 8 page main character syndrome PC backstory. If I found out my GM was doing that, they wouldn't be my GM anymore.

The DM determined that A) the players would find this crown, B) they would not clean it when they found it, and C) it would get cleaned at some point the DM decides later, whether the players wanted it to or not. Good for a book, bad for D&D.

IMO this is kinda one of the problems with DnD 5e, at least if you want to do certain kinds of stories.

The players just have so many tools at their disposal to do anything and everything that its hard to put them into a challenging situation that:

A) Doesn't involve combat

and

B) Isn't a completely artificial-feeling scenario that's been engineered specifically to negate all of the "I don't have to care about this" buttons that players have on their sheets.

I hate this take a lot, I'm gonna be honest. I don't care if his game is so on rails that it's set on the fucking orient express. As long as the players are having fun with the game, and the GM is having fun with the game.. that's a good GM.

I learned that best things come from the right balance between preparation and improvisation. And that balance is approximately 20-80 respectively, at best. I figured that as a DM, I'm also playing, so I roll with my fellow table partners, as the story is unexpected for me as is for them.

....

A) this makes no sense to describe as railroading, apparently finding anything plot or backstory related is railroading?

B & C) Players not doing what a dm expects isn't railroading. If the dm then turned around and said "no you don't do that" or decides to make it impervious to prestidigitation, that might fit the definition.

Railroading is removing player agency and not giving players choices. Players just doing something unexpected that throws you for a loop? That's called DMing.

The rust is removed, but there's significant chunks missing due to the rust settling in. It is still unrecognisable and needs restoration.

Or something magical based on what the artifact does

Yeah. At this point I try to prepare scenes rather than plots, so hopefully I'll be able to use my painstakingly prepared battlemap later, rather than not at all.

But it's fun when the players throw a total curveball, and I need to come up with something on the spot.

the rust scales begin to fall and as the entire party squints to see the results, ROLL FOR INITIATIVE AT DISADVANTAGE (fuck a few dragons will get me out of this shit)

What metal is the crown made of?

The spell only works on iron and iron-heavy alloys. An advanced version of the spell exists but the players don't have it yet.

Yep, the problem with 5e is all the bullshit exceptions to the rules you have to deal with. My biggest most obvious issue every player deals with is bonus actions. They were never playtested and added really late to 5e, and it shows. It's something like: you can use a bonus action for any action that says it can be used as a bonus action, except you can't cast a spell with it if you've already cast a spell this turn... except for some spells sometimes. The P2e method of everything just costing a set amount of action points, and if you have enough you can always do it, is so much better for players and DMs. It's just consistent and you know what to expect.

There's still plenty of room for the DM, but the rules can always be trusted.

DM: Scribbles a note "Without the rust it seems like a serviceable crown, but not too fancy."

Note to lost heir: "You see the crown and you think as it... looks at you. This should be your crown. You wants it. They shouldn't keep it from you. Steals it, hides it, it came here for you".

DM: "Probably worth some gold."