One of my favorite obstacles I've ever placed in front of my players was a cat asking who they were. They couldn't progress until they answered due to the nature of the path they were traveling, but there was literally no way to get it wrong. The cat would accept any answer that wasn't outright bullshit and would never hurt them for lying. The duelist steps up and gives his noble affiliation, the commoner fast talker steps up and gives a not-quite-a-lie. They both repeat this process expecting to fight or talk their way through a problem that just doesn't exist, the others being too worried to do so until the npc they brought with them does the same. Eventually they all answer, with the secret heir to the throne not even giving away his title, then flounder until one of them just walks down the road. It was great watching them be so paranoid over a little cat.

Oof. Sometimes.

I think about this situation a lot and how to avoid it.

We're playing a game of modern day secret magic. The players are looking for another group of NPC mages. They learned that they left the city, and wherever they are they are warded against magic generally and teleportation/scrying magic specifically.

The players decide to try to teleport to them. I say ok, but it's going to be difficult. I lay out the dice targets. They spend a bunch of time figuring out their dice pools and what bonuses they can get. They make the roll. They fail. Like, it was plausible they would win the roll with all their bonuses, but the dice did not bless them.

We move on a little. The next week, for Player reasons, they decide to try again. They go through the whole thing, spend more resources, and roll the dice. I tell them it's the same odds as before. I make the opposed check. Players fail again.

The player I liked least gets frustrated. "I don't understand what we're supposed to do! How are we supposed to find these people??"

I'm like "do you want a hint?"

They're like sure.

I go, "You could call them on the phone."

Dumbfounded.

"You could also ask their friend for the address of their safehouse she mentioned. She's been helpful so far."

"Oh."

In the game I started after, I brought this up in session 0. I framed it as "if something is opposing you, attacking it's strength is probably not going to work well. Like if there's a bouncer whose sole role in the world is to keep people out of the bar, asking him nicely to let you in is not likely to work. That's exactly what he's strong against. A bribe, a distraction, sneaking in, a fake VIP identity all have better shots than just asking nicely.

Or in other words, don't cast fire spells on the fire elemental."

I once had a session that became infamous amongst my group at the time. There was a magic forest that only the elves knew the way through, but no elves had come through for a while. One of the players was an elf, and I had given him a note explaining that there was a path featuring a sequence of specific species of trees, oak then spruce then elder, that sort of thing. He was supposed to go in the direction moss grew on said trees until seeing the new species, then look for the moss again, and so on and so forth. I expressly noted on the note that if he didn’t see the exact sequence of trees I gave in the note, “something had gone seriously wrong”.

Of course, the idea was that something had gone wrong and the path through the magical maze forest was screwed up, hence no elves arriving recently. My reason for setting it up this way was so that the elf would lead the party into the woods, he’d try to find the path, realize the path was broken, tell the party, and then they’d get down to the business of figuring out what was wrong and fixing it. You know… start the adventure.

Instead, what ensued was an entire multi hour long session of nothing happening. The elf would lead them. I’d tell him the trees they were seeing, out of order. He’d just keep following the moss, the “path” as he always did. I started emphasizing the wrongness of the trees he was seeing. He kept leading the party. I nudged him harder and harder. He just fucking kept going. The party was confused of course, as the whole path thing was supposed to be an elven secret that they didn’t share. And the elf player just kept ramming the entire party’s heads against the stupid wall for real world hours and I couldn’t stop it until I eventually dropped the 4th wall and flat out said this isn’t working, I’ve told you it isn’t working, please do something else! And then we had to end the session and start again next time.

It was incredibly frustrating in the moment, but it actually worked out well for the game as a whole. Became a running gag, a source of a lot of laughs, and it somehow ended up hammering in the point that something was wrong with the world and forest far more effectively than it might have if it had ended quicker. So good times in the end after all…

But MAN was it frustrating in the moment.

Many moons ago, I was in a campaign that featured a time traveling building.

Instead of progressing the story, we decided to test all the possibilities to essentially force the DM to establish which style of time travel is occurring. What was meant to be one session turned into 6 and we had a blast using dr.who logic to kill the big bad guy.

At this stage, my planning as a GM is to throw the situation at them, listen to their scenarios, and pick the one I like.

Pedro Pascal flipping through the script of an early Last Of Us Season 2 episode and noticing his character suddenly stopped having dialog.

I see this happen all the time with my players. I might be describing the environment they're in just to set the scene and they'll focus in on something specific. I'll set what I think is a fairly straightforward goal only for them to come up with an insane hairbrained scheme to accomplish it.

But the greatest one, I think, probably came when I was GMing the Lost Mine of Phandelver for a group of people completely new to roleplaying. We got to a section where they rescued a character they were after from a dungeon he had been trapped in by a doppelganger. I had the doppelganger transform into the trapped character, right in front of their eyes, and make a last-minute plea that he was actually the real prisoner and the other was fake. Claimed he had been transformed by a magical potion that had just conveniently expired at the right time.

I figured this was a last-minute hail mary on the part of the doppelganger, with zero chance of working. They'd immediately reject it and execute or capture the doppelganger and free the real prisoner. Instead, they spent easily half an hour debating which was real, casting spells like zone of truth and painfully agonising over every detail. They got it right in the end, but it was just hilarious to watch them completely overcomplicate what was meant to be a very simple bit of flavour text.

I was running a Mork Borg session once and the pc's came across a fountain in the middle of a cave. It was a pretty dirty cave, as is all of MB, but this fountain was just a clean, fresh, cool water source. It was like 10 or 15 irl minutes of debate and thought. I had one roll a random die and that triggered one players dog to drink from it. It was fine. They refilled their waterskins and one even washed their feet. It gets mentioned everytime there's an odd thing in a setting now.

That is some great alt-text. Thank you for including it

That’s also me, watching the other players make the situation far more complicated than it needs to be, but not wanting to be overbearing and ruin their fun.