Based on the episode Room With a Feud, Lincoln adjusts to having a new roommate with his youngest sister Lily, and he finds that it's more satisfying than having a room to himself and finds an opportunity to bond.
Lil' Roomie contains examples of:
- The Atoner: In chapter 8, Lincoln confesses he put up with having Lily as his roommate because he felt guilty of the times he lost her or used her for his own benefits.
- Big Ball of Violence: The siblings get into one in chapter 8.
- Big Brother Instinct: Played straight with Lincoln, but also inverted with Lily. When Luan starts making fun of Lincoln, Lily gets angry at her big sister and throws her pee-stained diaper at her.
- Big Sister Bully: Chapter 7 reveals Lynn acted like this towards Lincoln when they shared a room when they were younger before she warmed up to him.
- Call-Back: In Chapter 7, Lori alludes to the events of What is a Person Worth? by mentioning how Lincoln was once chased by a pack of dogs while wearing his squirrel suit from "No Such Luck".
- Cerebus Retcon: Lisa going on about all the ways they could die in the car wasn't her being a showoff know-it-all; it was her trying to stave off a panic attack over the matter.
- Turns out that, in this universe at least, Lola actually killed Seymour, and that's how she gets Lana's other pets to stay out of her things.
- Good Luck Charm: Another sister Fight Protocol almost breaks out after Leni washes Lynn Jr.'s lucky jersey. However Rita is quick to avert the idea by telling her jock daughter that it wasn't because of luck that she was untouchable on the field, she was untouchable because nobody wanted to go near the girl who smelled like she'd been rolling around in old garbage.
- Internal Reveal: In chapter 8, Lincoln confesses how he almost lost Lily once during the events of Two Boys And A Baby, and the incident in the mall from Mall of Duty.
- Lighter and Softer: Compared to the writer's other stories, which mostly focus on drama, Lil' Roomie is a heartwarming story mostly focusing on Lincoln and Lily's bond.
- Literal-Minded: Lana in chapter 8; when Lori orders her siblings to address the "elephant in the room", she thinks there's literally an elephant in the house and is disappointed to find out there's not.
- Mood Whiplash: Chapter 4 starts off as a cute bonding session between Lincoln and Lily after he picks her up from preschool but ends with both of them being scared stiff after nearly being hit by a car.
- Named by the Adaptation: The manager from "Cereal Offender" is revealed to be named Mr. Williams. This means he's named after his voice actor, Gary Anthony Williams.
- The Reveal: Chapter 7 reveals that the roommates for each of the Loud siblings as seen in the show are actually fairly recent. They went through several shuffles over the years. It wasn't even until Lily was born that Lincoln got the linen closet as his own room because his parents knew he would go through puberty soon.
- She Is Not My Girlfriend: Lincoln and Ronnie Anne react this way when Lily calls her his girlfriend.
- Shout-Out: Chapter 2 makes a reference to the Wii and Mario Kart.