I’m just a new baby DM but I like to think I know enough about storytelling to weigh in on this one, because It Bugs Me.
If you as the DM call for a perception check, you have fucking started something. You need to know what you are going to say whether they flub this roll or fucking ace it. You don’t get to say ‘roll perception’ and then respond to a 12 with ‘uh, never mind.’ NO! The characters have already Had A Feeling About This! That’s why you’re asking for a perception check instead of just using their passive perception!
Everyone on this fucking planet has whipped around to see an ominous shadow moving except it was actually just a bug. Use that!! Have perception checks where the cigar is actually just a cigar!! Or else your perception checks where a cigar is actually a mimic are just irritating your players by telling them something’s up but they don’t get to fucking act on it!!
I may not be an experienced DM but I am a garbage theatre student and I fucking know what it looks like when someone in a scene drops the fucking energy ball.
You don’t just stick a gun on the mantel and then go ‘oh wait never mind’ or Anton Chekhov rises from his grave to fistfight you behind a gay bar you didn’t know existed at three in the morning after an ill-advised Jaeger bomb.