Note: This is regarding female love interests for male characters. There are many potential relationship pairings, and to keep things simple, I’m examining them one type at a time.
One of the first things to consider when you are considering creating a romantic interest for your protagonist is why you are doing it. Your motivation can determine where to go from there.
Because Someone Said I Had To
While it’s true that romantic entanglements can spice up a story, be sure that it isn’t just an afterthought. A lot of stories have a romantic interest shoehorned in, and it becomes apparently pretty quickly. Rather than adding to a story, this ends up taking time away from the plot you actually spent time working out.
It’s the Whole Point
OK, so you’re writing romance or one of the romance subgenres. Fair enough, and we won’t trouble you any further on the subject.
I Just Had a Bunch of Characters and It Sort of Happened
So you wrote a bunch of characters, some male, some female. Literature happened, and these characters decided among themselves that this was the way things were going to be. Either there was just chemistry among them, or the plot demanded they get together, there was at least some compelling reason for the relationship to be portrayed in the story. Carry on!
Now that you’ve determined why you are adding a relationship, think about what type it would be:
Damsel in Distress
You’re going to need a ladder, because you started yourself off in a hole. This is one of the most overdone romantic relationships in fiction, and ham-fisting your way through it will leave you looking like a hack. In the classical context, the damsel in question has been captured by a dragon and held in a tower. You can play Mad-Libs with that last sentence all you want, but it boils down to “girl in trouble, must be saved, will fall in love with hero.” The dragon can be replaced with a gang of thieves, an evil wizard, a drug cartel, or a corrupt government.
You can rework the plot and swap the poor girl out for a magic sword and the story doesn’t change much. In the end, the hero has a cool new sword instead of a fiancee. She was a prize, and not a very well-rounded character.
If you want to use this tired old trope, twist it around somehow. Have the “damsel” be the one arranging her own capture to get the hero’s attention. Have her thank the hero and run into the arms of the man she loves as soon as she gets home. Find some way to make it new and interesting.
Girl Next Door
The girl next door summed up in one word: wholesome. Usually naive, always sweet, and in most cases, suspiciously available (in fact, you may need to address the issue of why this girl isn’t awash in a sea of suitors). Most often, she is looking for a particular sort of person, her ideal man. If the protagonist is going to win her heart, he needs to become that sort of person. This is a common romantic pairing for coming of age stories or ones where the protagonist needs to reexamine his life and priorities.
While the “princess” part doesn’t have to be literal, it’s the origin of this type of romantic interest. She is cooped up in a lifestyle she hates, and feels hemmed in by familial obligations. She may even be subjected to an arranged marriage (which she wants no part of). If the protagonist of the story is male, he’s often blundering into the princess as she is looking for a way out of her situation. She may end up using the protagonist, she may genuinely fall in love with him, or she might just diverting herself with the polar opposite of the man she’s supposed to be marrying (if you’re doing the writing, make sure your protagonist and the arranged fiance are distinctly different).
Just my opinion, but this is one of the least likely situations to result in a healthy long term relationship.
Not all heroes have their act together. If your protagonist leads a wild, dangerous life, he may need to find someone to make him slow down and think about his actions. While the stabilizing influence may disapprove and actively discourage the protagonist’s reckless ways, she may also just be the sort of woman who makes the protagonist realize that it’s worth settling down a bit in order to keep her. This is a good pairing for the scoundrel, the thief, the daredevil, or the think-with-my-gun types of heroes. Settling down with a stabilizing influence can be a good way to wrap up a story.
(note: if your reckless hero is getting a sequel, this relationship may be in trouble)
Friend Since Childhood
They’ve known each other for as long as either of them can remember. There is nothing they don’t share — oh yeah, except that. For the reader or audience, this one seems obvious as soon as the depth of the relationship is established. It’s possible that they’ve just never thought about one another that way before; it could also be that one of them has and has been secretly hoping the other will say something or make the first move.
Most often, there’s going to be a long lag between the reader’s realization that they’re meant for each other and the characters’ realization of that same fact. This will most often involve other (failed) romantic relationships for one or both of them.
Wellspring of Trouble
The source of all things unfortunate for the protagonist is most often not the ultimate partner for him. This archetype can run the gamut from the “bad girl” (insert type of bad girl of your choice) to the one who is always having bad things happen to her through no fault of their own. Whatever the reason though, this woman is a source of trouble for the protagonist whenever he gets involved with her.
One version of this would would be the criminal. She could be involved in drugs, prostitution, a gang, anything that puts her daily life at odds with lawful society. The protagonist is drawn to her for any number of reasons, from the appeal of the lifestyle to simple physical attraction. The protagonist could also feel a need to “save” her from her circumstances (whether she actually needs or wants “saving” is up to you).
Another version put her more into the “rebel without a cause” category, where her actions aren’t illegal, just counter to mainstream culture. This can provide tension if the protagonist is the by-the-books sort, looking for approval from society (possibly because he has a respectable job, or is trying to get promoted to one). This is a good transitional romantic interest to a stable influence, girl next door, or friend since childhood.
Lastly, this could also be used to describe a woman who is the catalyst for bad things to happen. She may be a poor decision-maker, have unreliable friends and family, or simply have been born under an unlucky star (if you’re writing a genre in which supernatural elements exist, this could be literal). Unlike other incarnations of this archetype, this wellspring is a keeper. By either changing her fate or her circumstances, there’s a happy ending to be had.
The common thread in all these is that this romantic love interest is a direct kick-in-the-plot to your protagonist.
Some Type of Actual Person
What do you call it when two people share common interests and values, meet through work, church, or other common acquaintances, then proceed to date casually for a while before moving on to a more serious relationship? I think the technical term is: normal. Envision a girl who wasn’t created to fill a gap in a story, but was created independently, with a backstory, family, education, career, and dreams of her own. Then have her meet your protagonist. There may be some dramatic potential here, but unless you’re writing romance, you may want to keep the nuts and bolts of this relationship off-page. While it is an admirable goal in real life, healthy, stable, slow-moving relationships usually aren’t good for turning pages and keeping eyes on a screen.