As a storyteller, the rules of reality don't apply so much to us. I think that's one of the major drawing cards to novels: anything can happen, and sometimes it does! However, it's like jumping off a cliff--just because you can do something, doesn't mean you should! No matter how "out there" your story make go, it always has to be rooted to some form of reality for your reader to relate to it.
For example, look at Spider-Man. While I can't say any of us can shoot webs or climb walls, it's safe to say we've all had some unrequited love in our life, or we've struggled with our self-confidence. See, even when dealing with a character as hard to relate to as Spider-Man, there's always that "Peter Parker" side that we can relate to. A good writer always allows his characters to keep that ground in reality somewhere.
How about the plot? While a good story has the protagonist going through a ton of stuff on the way to reaching his goal, you still have to keep it real. You can't have the hero get shot at by bad guys, so he steals a car to get away--except the car's brakes don't work for some reason...and he's heading downhill in San Francisco...and there's a nuclear bomb being transported across the U.S. and it just happens to be at the bottom of that hill at that moment...and the hero's seat belt gets stuck...and a bird happens to be flying by and deposits something on the windshield so he can't see...and....well, you get the idea.
One of the biggest examples of this is a book by a very popular author (no name dropping). In the book, he seems more in love with the villain than with the heros. As a matter of fact, absolutely nothing goes wrong for the villain, but everything does for the heroes. The villain commits a heinous crime, but it's caught on video. He leaves, then decides to go back to the scene one more time. He walks in at the exact moment someone is watching the tape from the hidden camera. He steals the tape and destroys it. Aha! But the heroine has had time to call someone while he was out and left a message on their answering machine about what she'd seen on the tape. The villain pursues the heroes, but they get away. He goes to their house while they're out to look for them. Out of the entire house, he opens the one drawer that contains the tape they had. How lucky! But wait, it gets better! While he's there, the airline calls to tell the heroes that there's something wrong with their credit card, but it can be fixed when they arrive at Gate 9 at 9 AM tomorrow going to San Antonio on Flight XYZ! How lucky can one guy get? It goes on from there, but I think you get the point. The rules of reality have been bent so far that the reader has lost the disbelief in the story.
Be careful when you write. Keep a touch of reality in everything. There's no reason the character can't be put into trouble. There's no reason the truck can't be hurtling down the street at the perfect time to try and hit them. There's no reason the villain can't find that crucial piece of evidence against him and destroy it.
Just make sure it doesn't all happen at once.