Your characters meet, fall in love, and decide to face the rest of the novel’s adventures hand-in-hand, where nothing ever comes between them. Sweet, right?
You can certainly pull this off and add tension in other ways, but romance can be a great source of conflict that keeps your readers' turning pages. Sweet is nice, but it's not always the best choice for your story. There’s a reason Friends drags out Ross and Rachel’s relationship until the series finale.
In fiction, there's often something that keeps your lovestruck characters apart, and this is true for all genres, though I’m obviously going to focus on sci-fi and fantasy as examples here. If the romance has a tragic ending, the obstacle succeeds at separating them. If it has a happy ending, the lovers overcome the obstacle.
Below are ten reasons your characters might be parted.
1. Duty
Examples: Aragorn and Arwen (The Lord of the Rings by J.R.R. Tolkien), Nynaeve and Lan (Wheel of Time by Robert Jordan), Ead and Sabran (The Priory of the Orange Tree by Samantha Shannon), Dean and Lisa (Supernatural)
In The Lord of the Rings; Aragorn doesn’t want Arwen to suffer by marrying a mortal man. Arwen is supposed to leave Middle-earth with the rest of her elven kin, and Aragorn has his own path to follow. Their love seems doomed, which makes it extra special when Arwen shows up at the end of Return of the King, having stayed behind in the hopes that Sauron would be defeated, Aragorn would survive, and their love would prevail.
2. Stubbornness or Fear
Examples: Mal and Inara (Firefly), Kaz and Inej (Six of Crows by Leigh Bardugo), Starbuck and Apollo (Battlestar Galactica), Han and Leia (Star Wars)
This is one of my favourite tropes. There’s just something amusing (and frustrating) about watching characters who love each other but refuse to get together. Most often, the reason behind their stubbornness is a deep-seated fear about commitment or about being hurt.
In Firefly, Mal and Inara obviously have feelings for each other, but neither makes a move because they don’t like complications (and they’re both afraid of being rejected and/or hurt by the other). The tension between them builds over each of their scenes together and sparks fly in their dialogue.
3. Professional Reasons
Examples: Chuck and Sarah (Chuck), Jack and Sam (Stargate: SG-1), Adama and Roslin (Battlestar Galactica), Tony and Pepper (Iron Man)
This is similar to duty, except closely tied to one or both of the partners’ careers. In Chuck, Sarah is Chuck’s CIA handler and bodyguard; her judgement would be impaired if she was in a romantic relationship with him, so she wants to keep things professional (of course, there are other reasons why she is afraid of having a relationship as well, such as past trauma and difficulty trusting others).
With this type of obstacle, there is often a power dynamic going on, where one character is responsible for the other. This could also be a boss/subordinate, teacher/student, General/Captain, doctor/intern, etc.
4. Enmity
Examples: Katniss and Peeta (The Hunger Games by Suzanne Collins), Eris and Safire (The Sky Weaver by Kristen Ciccarelli), Clarke and Lexa (The 100), Adora and Catra (She-Ra and the Princesses of Power)
Enemies to lovers! Who doesn’t like this trope? Come at me.
When characters are on the opposite side of a war or politics (or maybe they just hate each other), tension rises. In The Hunger Games, Katniss doesn’t want to fall in love with Peeta, because she knows she has to kill him to survive. They are technically enemies, so everyone breathes a sigh of relief when the rules change in the middle of the Games, and they’re permitted to become allies. In The Sky Weaver, a thief taunts a commander by stealing something valuable to her, and the two engage in a cat and mouse game (though it’s often not clear who is the cat and who is the mouse). Their fiery exchanges are delightful to read.
5. Relationship Status: Taken
Examples: Harry and Ginny (Harry Potter), Jack and Allison (Eureka), Nancy and Jonathan (Stranger Things), Wolverine and Jean Grey (X-Men)
Drama and inner turmoil escalate when a character is in love with someone who’s already taken. In Stranger Things, Nancy is with Steve when the sparks fly between her and Jonathan. It was hard to know who to root for in this case, because Steve was a jerk at the time, but Jonathan was a creep (I’m sorry, why are you hiding in the bushes photographing your classmates while they’re hanging out in a pool?). Just goes to show that we don’t have to be pulling for either option.
Of course, now that Steve’s awesome, I’m Team Steve. Or maybe Team Robin. Scratch that; Team Robin all the way.
6. Obliviousness
Examples: Sheldon and Amy (The Big Bang Theory), Buffy and Spike (Buffy the Vampire Slayer) Mal and Alina (Shadow and Bone), Eren and Mikasa (Attack on Titan)
Sometimes, this trope just ends in unrequited love, where one character rejects the other. Other times, when one character realizes the other has feelings for them, they fall in love too. In Buffy the Vampire Slayer, it’s a bit of both. At first, Buffy is shocked and disgusted by Spike’s feelings for her, but she eventually falls for him because he is loyal and understands her (plus a bunch of trauma and the belief that she doesn’t deserve better).
I’m not sure how realistic overcoming this obstacle is, but some stories do embrace the idea of, “Oh, I just never thought about you that way. Well, yeah, okay, I love you, too,” and it works.
7. Circumstances Beyond Their Control
Examples: Buffy and Angel (Buffy the Vampire Slayer), Rose and the Doctor (Doctor Who), Stamets and Dr. Culber (Star Trek: Discovery), Vision and Wanda (WandaVision)
Funny how the magic of romance can be killed by literal magic. Particularly in sci-fi and fantasy, the galaxy’s the limit with these obstacles. Your characters could be stuck in different times, on different planets, in a magical coma, separated by parallel universes, magically enslaved, wormholed, befuddled, charmed, cursed, you name it. In WandaVision, Vision is literally not real—created by Wanda’s memories and magic. Watching her have to face his death again is heartbreaking.
8. Unrequited Love
Examples: Steve and Robin (Stranger Things), Tristan and Yvaine (Stardust), Aang and Katara (Avatar: The Last Airbender), Kvothe and Denna (The Kingkiller Chronicles by Patrick Rothfuss)
One of my favourite moments in Stranger Things is when Steve admits he might have feelings for Robin, and she responds by letting him know she doesn’t swing that way. Instead of reacting in anger or disappointment, Steve responds with friendship, and their relationship henceforth is amazing. Stranger Things proves that people don’t have to get together to have a happy ending.
9. Hidden Motives
Examples: Sam and Ruby (Supernatural), Alina and the Darkling (Shadow and Bone), Sky and Ward (Agents of SHIELD), Littlefinger and Sansa (Game of Thrones)
At least one character is not being honest with the other, often for nefarious purposes. The relationship between Alina and the Darkling in Shadow and Bone is riveting because we’re not sure of the Darkling’s motives. He’s definitely hot, but is he good? Time will tell.
10. Interference
Examples: Henry and Kim (Eureka), Buttercup and Westley, (The Princess Bride), Lily and James (Harry Potter), Kirito and Asuna (Sword Art Online)
Someone doesn’t want these people together and has done everything to stop their union. In Eureka, Jason Anderson literally steals Kim and Henry’s memories of falling in love together so he can marry her instead. This is a great obstacle to make your villain more villainous—they not only want to do whatever other evil things they’re doing, but they want to interfere with your characters’ happiness! The nerve!
Honourable Mentions to the following obstacles: “They’re Related” (Marty and his mom, Back to the Future), “He’s Dead” (Upload), “She’s Sleeping with his Son” (Angel and Cordelia, Angel), and “Whoops, He Turned Evil and Killed Hundreds of Children” (Anakin and Padme, Star Wars).