He was not the dashing hero from the glossy covers. He was a structural engineer, with kind, tired eyes and a perpetual smudge of graphite on his right hand. He didn’t browse; he had a list. A very specific list.

To see these principles in action, look at the evolution of the romantic comedy. The 1990s (the Nora Ephron era) gave us Sleepless in Seattle , where the relationship was about destiny. The 2010s (the Judd Apatow/Lena Dunham era) gave us Trainwreck and Girls , where the relationships were about messy, flawed humans learning to tolerate each other.

Example : High Friction + High Intimacy unlocks the scene, while High Loyalty + Low Intimacy might trigger a "Silent Guardian" subplot.