When a writer sits down to pen a script, adding a betrayal to the drama is a sure-fire way to amp up the emotional explosiveness. When a movie features a betrayal, and it's done right, it can be a jaw-dropping and powerful experience for the audience.
Some movies have been awarded Academy Awards for Best Picture for their ability to move us immensely due to onscreen treachery. Watch Braveheart online for evidence of the fact that having a turncoat equals Oscar gold!
Others become iconic with their double-cross providing the moment in which the movie turns towards its thrilling climax.
Just watch The Matrix online and there is Cypher doing his dirty work that almost costs our rebels their lives. And let us not forget what Saruman did when you watch The Lord of the Rings: The Fellowship of the Ring online.
We found 17 of the best (worst) movie betrayals... click through and see who made our list of favorite double-crosses!