2 points
“The door seems normal to you.”
players proceed to analyze the door for an hour, not realizing if they take the stairs slightly to the left, they’ll be taken to the treasure room they’re looking for
I’ve gotten impatient before and snapped “the door rots away from the time you’ve spent arguing and falls open” which just sparked a few minutes of debating whether the building is sentient and will eat them if they enter the door.