I've been reading a lot of scripts and watching as many movies as I can, both good and bad. It was in the bad scripts and films that crystallized what makes great movies great, and scripts intriguing.
I've noticed three main aspects of a screenplay/film that every writer needs to infuse in their script to ultimately end up as a great film. Inversely, I've noticed a huge lack of these three elements in terrible movies - which proves the point more-so.
Numero Uno (that's number one for the laymen) -- Make Me Care!
If you're watching a movie, and you're bored, more likely than not you just don't give a damn about the character, or what's going on. Many a times I've thrown back my head in the theater and muttered "Ugh, I don't care!" This has its roots in empathy. Why should we be rooting for the hero? Why do we want him to succeed? Why do we care?
Good Example: In Kill Bill Vol 1. The Bride, who's pregnant and at her rehearsal wedding, gets shot in the head after witnessing her fiance and friends die. In the hospital she's alive, but has been in a coma for a while, and during the coma she's been raped and her baby is gone. Like... wow. That pretty much gives her a pass to do whatever she wants to exact her revenge. You have empathy for her, and you care that she gets justice. So we're totally down to watch her kill dozens of people to find out what happened, and why, and get her revenge. I care about her because I'm human and can empathize with her.
Bad Example: All Is Lost. Although an old man is about to die at sea cause his boat's sinking and there's a shark in the water that fails to do us all a favor and end his life - I didn't give rat's behind if he died or not. He didn't win me over, he didn't do anything to make me root for him, he's just another human trying to survive, which is good, it does elicit some empathy, but not enough for me to care.
Another quick example is almost any Adam Sandler movie as of late. Jack and Jill, That's My Boy, Blended, I didn't care, and many others didn't either. The character keeps playing a well off, rich guy who has very shallow problems. Shoot him in the head and rape him! Then I'll care. Or have his grandmother in a crooked home while he's trying to win money playing golf to win back her home, then I'll care. Or give him a fatal disease. Funny People was his last great movie, for just this reason.
Make me care. Instill empathy, and elicit emotion in me via the hero. Cause if I don't care about them, I don't care period.
#2) The Hero Must Be A Changed Person By The End
The point of the hero's journey is to change him in the end. If he starts off as a blind, army vet that wants to kill himself, by the end he should want to live and be happy with his life. That's why I love Scent of a Woman.
If you're a neo nazi who hates Black people, by the end of your journey you better not be a nazi, and befriend at least one black guy, and denounce your racist ways. American History X does this perfectly.
Your hero has to change, or else what's the point?
And Three -- Conflict!
Conflict, oh, conflict. Obstacles, bad guys, depression, a sickness, please, oh please, give your hero as much conflict as you can.
In every page, scene, act, reversal, infuse conflict to the best of your ability. Without conflict you get bored, and when you're bored you don't care. Which brings this back to numero uno, make me care.
Gravity, holy Moses, Gravity was a roller coaster ride. With the second half being a straight free fall downwards. So much conflict. It never lets up. It made the film exhilarating to the last second.
Again, Kill Bill Vol 1 and 2, so much conflict thrown at The Bride. Being buried in a coffin alive, fighting off the Crazy 88's, being shot in the head! Hello! Conflict up the wazoo.
Now, there are some movies that don't have a personified antagonist, and they still are very exciting to watch. Little Miss Sunshine. They have conflict peppered throughout, but no one's really stopping them from getting to the pageant. A faulty van, some self doubt, it's all that gets in the way. But the story and writing are so well done, it's never boring. Hell there's even a death.
Superbad. Again, no antagonist. Even the cops are cool in the movie. The one, quick, slight antagonist is the guy who spits on Seth's shirt and doesn't invite him to his party. But so what? Jules has a party and he's invited, and that's what the movie's about. But still, for good measure, that guy gets a club to the face ala Bill Hader at the end. Which was well deserved. The movie is layered with conflict and obstacles, though. Making it a fun ride, and full of laughs.
Conflict is the antidote to cure boredom in movies. If a movie is boring, it probably has no conflict.
One movie I want to point out is The Wolf Of Wall Street. I loved this movie from beginning to end. I just watched it again the other day. Flew by, despite it being almost 2.5 hours.
Here's some things I felt about it that go against these rules: I didn't really care about Jordan's mishaps. I'm sorry, I can't feel any empathy for someone who's stealing millions of dollars from hard working people then running into his own bullshit problems cause of it. You get little to no sympathy from me cause you lost your girlfriend, got arrested, and can't control your lude's problem. But here's the thing, I was never, ever, once bored. And by the end, he was a changed person. He had his fair share of conflict, but that's like watching Hitler being beaten up by 20 Jewish boxers. Who cares about Hitler? He deserves getting his ass kicked. WOWS did it well enough that it was a great movie.
Scorsese in general did a great job. As with Goodfellas, you still have a "bad guy" who's the anti hero, rich, mobster you're rooting for, but I think we get to know Henry Hill a lot better than Jordan Belford. We're okay with mobsters killing mobsters, rather than rich stock brokers stealing money from people who don't deserve it. Ya know?
So there you have it. Make me care, have a character change by the end of the story, and add conflict as to not be boring! It's all about entertainment and connecting with the characters. This is how you do it, and those who do it well are memorable films.