Post History
Here's an easy test: if for all intents and purposes the woman in your story could be replaced with a golden chalice, you're in trouble. Someone stole the guy's chalice, he wants to get it back. So...
Answer
#4: Attribution notice removed
Source: https://writers.stackexchange.com/a/47920 License name: CC BY-SA 4.0 License URL: https://creativecommons.org/licenses/by-sa/4.0/
#3: Attribution notice added
Source: https://writers.stackexchange.com/a/47920 License name: CC BY-SA 4.0 License URL: https://creativecommons.org/licenses/by-sa/4.0/
#2: Initial revision
Here's an easy test: if for all intents and purposes the woman in your story could be replaced with a golden chalice, you're in trouble. Someone stole the guy's chalice, he wants to get it back. Someone crashed the guy's chalice, he wants revenge. Worst offenders are the "if you save the princess, you can marry her" stories - there the woman is literally a reward. What makes a character different from a nice cup? **The woman has agency.** In @Amadeus's example of the child in the river, the child has no agency, but that is a very brief situation. If your hero is going on presumably a novel-spanning quest to save his love-interest from a dragon, what is the love-interest doing all this time? Presumably more than sitting on a shelf in the dragon's fridge and doing nothing? It might be that the lady can't escape the dragon on her own. A war prisoner often can't escape either. But the war prisoner is doing _something_, right? Another related trope you want to avoid is the woman's agency _always_ landing her in trouble. If every time the woman exercises her will instead of doing what the man tells her, she then needs saving from the consequences of her actions, that's problematic. That's saying "men know better, women should obey" and "women are incapable of taking care of themselves or making good decisions". A lady gets kidnapped by a dragon. Why? Because she went out to pick flowers all alone, when she was told not to go out of the palace? Or was it that she was championing a dragon-hunting coalition, getting the villages armed against dragons, actually pushing dragons back so they felt genuinely threatened? See the difference? Neither does the hero need to do the saving all on his own. Surely his beloved can be useful in some way? Surely, he's not all-powerful, all-knowing, made-of-steel, one-man powerhouse who needs no assistance ever? Human heroes are more compelling. And finally, don't forget about other female characters in your story. Every problematic trope discussed by me and by others is exacerbated if _every_ female character in your story is flat and useless or worse than useless, or if there are no other female characters in the story at all.