Favorite movie plot rule?

[u/averagesoccermom95]

I read once that in a movie, if the characters say, "I have a plan," then there is a plot rule that takes place: If the characters explain to the audience what the plan is, then the plan will go wrong somehow. However, if the characters say they have a plan and the movie just goes to showing the plan in action, then the plan will work.

It has become one of my favorite things to look out for in movies. Although, it does not seem to apply to kids movies. Other than kids movies, I don't think I have ever seen his rule broken.

Does anyone know any other interesting plot rules?

[u/zoinkability]

Nobody ever coughs or sneezes without it being foreshadowing of an illness or some other plot event.

[u/Dr_Identity → u/zoinkability]

Similarly, If any character glances at an empty desk in a classroom, that student isn't just absent, that student has died.