An archetype is based on a character, story, or object that is based on an already known character, story, or object. An archetype is a derivative of a standard—like a hero modeled after Hercules or a playboy modeled after Casanova.
A trope is something that follows across a genre, like certain spooky stories beginning with “It was a dark and stormy night…” We instantly recognize what kind of story we are about to hear with that line. The same is true for fairy tales ending with “happily ever after” and beginning with “once upon a time…”
Tropes are tricks of writing we can use in our favor. Breaking a trope can throw a reader off the trail to an unexpected surprise. When the good guy wears black and the bad guy wears white, readers can follow the wrong rabbit trail to an unexpected conclusion. But know the trope first.
To make that easier, I just found TVTropes.org, a site that collects and shares tropes. I’ve enjoyed looking through the categories. They are divided into a list of indexes and split into conceptual groups. Have fun browsing all the tropes and let me know how you use tropes in your own work. Visit TV Tropes here.
From their site: Tropes are not the same thing as cliches. They may be brand new but seem trite and hackneyed; they may be thousands of years old but seem fresh and new. They are not bad, they are not good; tropes are tools that the creator of a work of art uses to express their ideas to the audience. It’s pretty much impossible to create a story without tropes.