“They” say there are only seven plots in the world. Not sure I believe that, but I do know that certain plot points are used over and over. The inept writer will use the tried and true while the bestselling author puts their own mark on it.
For instance, if a character gets sucked up into a tornado, they’ll die…unless they’re Dorothy from Kansas. A gunshot to the head means death, right? Not necessarily. Depending on where the shot enters and leaves the skull or the caliber of the bullet, a character could survive, though they seldom do without some kind of neurological damage. Think Harrison Ford in REGARDING HENRY.
I happen to love the cheesy SF “monster” movies on the SyFy channel. They all have the same plot and I don’t have to pay close attention which is handy when I’m doing something else like laundry or dishes. There is the creature, usually big and fast and constantly angry. They sweep through the landscape, killing every half naked female they can find. Their one good aspect is they always kill the greedy land developer/resort owner/mayor/whatever.
Never mind that most animals hunt only for food and usually don’t attack humans unless threatened or protecting their young. Never mind that most animals who eat large prey usually have to digest the first one before they eat another. Or that the law of aerodynamics make mosquitos 10 feet long unable to fly, though it is cool when they get squashed by the semi-truck.
In other words, those writers write SF stories with little science.
Even better SF movies often have problems. I loved the Mel Gibson movie SIGNS and bought into the entire plot, aliens and all, right up to the end. But as I walked out of the movie, the first question that hit me was how could water hurt the alien when breathing out atmosphere didn’t? Earth has a pretty moist atmosphere, even with drought and the aliens should have choked to death the minute they stepped out of their ship.
H.G. Wells understood that when he wrote WAR OF THE WORLDS. His aliens never left their ships; they sent their robots to do the hand to hand battle. But they weren’t protected from the bacteria in our air that their ships couldn’t or didn’t filter and that did them in. I LOVED that little nugget when I first read the story!
So, you intrepid authors, never mind whether your plot’s been used before; it probably has. It’s in the plot sections where you need to shine. Don’t have your heroine go down into the dark basement…unless she is fully armored and armed, ready to kick creepy person or creature’s ass!