4. Don't Contradict Your Main Characters
Like the villain, contradicting your protagonists causes confusion. It's not shocking for a hero to act out of character, but it doesn't mean it should be ignored.
Worst Offender: Kick-Ass 2: The first film establishes the main character's motivations, ideals, and morals. Dave Lizewski is a depressed teenager in love with Katie Deauxma and obsessed with superheroes. He is a good son who loves his father and would never do anything to hurt him. Katie is a very kind and understanding young girl who volunteers at a needle exchange. Kit-Girl/Mindy Macready was trained by her father, Damon Macready, to fight crime and kill bad guys. She befriends Kick-Ass and protects him countless times. In Kick-Ass 2, these characters contradict themselves for the plot to continue. Katie quickly changes from kind and understanding to b*itchy and unperceiving when she believes Dave is cheating on her with Mindy. Instead of listening to him, she breaks up with him even after he tells her it was Kick-Ass related. Hit-Girl contradicts herself when she declines Dave's desperate plea to free his father from jail. Both made a pact to always help each other no matter the danger. Both were always there when they needed each other. But it is Kick-Ass who contradicts himself the most. The worst contradiction came from the writers when they ignored his "superpower." If you recall, his nerve endings were altered after a stab wound and car hit. His life-threatening injury leads to him feeling no pain and capable of taking prolonged beatings. Only weapons like baseball bats can severely hurt him. In KA2, any type of attack hurt him whether it was punches, kicks, or garbage cans. Normal thugs and Chris D'Amico should not have been able to hurt him so easily. The most personal contradiction was his verbal assault on his father. Before the scene, Dave showed no signs of animosity against him, only a son's love. That's why it was so confusing when he berated his father after he found his Kick-Ass outfit. He told him his life was meaningless and no one would care if he died. This scene makes no sense, but Dave needed some type of lesson after his father is killed. Ending on bad terms with a father and then him dying is a cliché in film and I was disappointed the movie took this route.
Best Example: None: Every superhero contradicts themselves at some point. While they are super-beings, most of them are human and capable of mistakes. Even gods and Kryptonians aren't perfect. Tony Stark contradicts himself when he destroys his suits and removes the Arc Reactor. Wolverine quickly breaks his promise never to use his claws 10 minutes into the movie. Loki is a walking contradiction, but we still love him. Thor contradicts his sense of honor when he disobeys Odin's orders not to leave Asgard. He also contradicts the lessons he learned from the first film when he escapes Asgard and faces Malekith. Superman contradicts his moral code when he steals clothes and destroys a truck driver's source of income, even if he deserved it.