When do you allow your world's inhabitants to make their own choices? And what are the consequences?

I've been thinking about how to write my story and I have a question about world building. My story takes place on Earth (it's a retelling of *Romeo and Juliet*, with a supernatural twist). However, there is magic. So when it comes to certain things, how far should I go? For example, when I have characters in life-threatening situations, can they just "cheat" and have something go their way? Or is the situation resolved fairly, but not in a way the character wants? <br><br>Let me give an example. I have a character who is in a bar fight. It's just a fight with some kids who were being disrespectful, and the main character had enough and punched one in the face. The bouncers see and kick him out, which is fair, right? Or should I make it so the bouncers are big, menacing men who throw the character out violently? This would be realistic, but I think it would make my character look bad, even though he's in the right.