Yesterday, I reviewed a screenplay that had problems. Overall the screenplay was decent, but some of the character conflicts felt contrived. The writer had gotten so wrapped up in the theme and execution of certain plot elements that she tried to re-invent the wheel and created more work for herself than was really necessary.
My notes were brutal. The characters lacked some very basic and inherent differences that would make the conflicts come naturally. Instead, those differences were built-in after the fact so the conflicts felt contrived. They felt contrived because they WERE contrived.
Stupid Example (because I'm too jacked up on black eyed peas to come up with a good one): Four people sit at a table and argue about what appetizers to order. Simple scene to stage if you already know who likes what. Difficult if you have to figure it all out at the table.
AA - Character one is allergic to shellfish and hates mushrooms
BB - Character two loves shellfish and loves mushrooms
AB - Character three hates shellfish and loves mushrooms
BA - Character four loves shellfish and is allergic to mushrooms
That same character grid creates natural conflicts over more relative character issues like love interests, career goals, sexual orientation, religion, politics, and child raising.
Oh, and the author took my notes very positively. After all, the screenplay was my 2006 Nicholl Fellowship application.