"I love it when a plan comes together."

Roger Ebert's Little Movie Glossary contains great observations from both Ebert and his readers about film conventions that have developed over the years. Here's one of my own:

In any film that involves a plan of action, you can be guaranteed of the following:

(A) If the plan is explained in detail for the audience, then something (or multiple things) will go wrong with it (Back to the Future, The Great Escape and The Dirty Dozen).

(B) If the plan is partially or entirely concealed from the audience, it will most likely go off without a hitch (Ocean's Eleven, The Sting and Where Eagles Dare).