In some fanfiction, Prim has the ability to communicate with animals, which is a trait not seen in the original Hunger Games series. She uses this ability to gain allies in the forest outside District 12. This not only helps her survive but also helps the people of District 12 when they are in trouble. It gives her a special power that makes her a more central and interesting character in the fanfiction world.
One unique plotline could be Prim being chosen for the Hunger Games instead of Katniss. This would completely change the dynamic as Prim is much more gentle and less trained for combat. Another could be Prim having a special connection with the Capitol's secrets, like she discovers a way to bring down their defenses through her knowledge of plants, which she uses as medicine in District 12.
There's a fanfiction where Prim is a secret agent for an underground group that's planning to overthrow the Capitol long before Katniss becomes the Mockingjay. She uses her innocent appearance to her advantage and gathers intelligence. It shows a side of Prim that is very different from her portrayal in the original books, as she's much more proactive and daring in this plotline.
One interesting plotline could be an alternate version of their time in the arena. Maybe they find a hidden part of the arena that has some kind of special power or resource that changes the game completely. For example, a place with healing waters that not only heals their physical wounds but also gives them some mental clarity, allowing them to outwit the other tributes more easily.
One interesting plotline could be Peeta and Katniss having to survive in a different kind of arena that has unique challenges not seen in the original games. Maybe it's an underwater arena where they have to figure out how to breathe and find food. Another could be a plot where they secretly raise a rebellion within the Capitol itself instead of just in the districts.
In some fanfiction, a great plotline is that Peeta and Katniss are forced to participate in a special Hunger Games - like event again, but this time it's more of a political ploy. They have to outwit the Capitol in different ways than before. Maybe they form alliances with unexpected people from other districts and find new ways to resist the Capitol's tyranny while also dealing with their complex feelings for each other.
One possible scenario in a fanfiction about Katniss' twin sister could be that she has a different set of skills. For example, while Katniss is known for her archery, the twin sister could be excellent at herbal medicine. This would add an interesting dynamic to the story as she could use her skills to help the tributes in different ways, perhaps by creating remedies for injuries or poisons. It could also change the relationship with Peeta, as the sister might have a different approach to the whole Hunger Games situation.
She might be a mentor - like figure in the fanfiction. Since she is Katniss' twin, she has seen the brutality of the Games up close. So, she could take it upon herself to train the younger tributes from her district, teaching them not just survival skills but also the importance of unity and standing up against the Capitol. This would create a new role for her in the story and have a big impact on the future tributes from her district.
Well, it depends on the specific fanfiction. There are countless Hunger Games fanfictions out there. Some authors might choose to kill off Katniss to create a more dramatic or thought - provoking story. For example, they could make her sacrifice herself in a different way than in the original books, perhaps to save the whole of Panem in a more extreme situation.
One possible fanfiction could be about Katniss and Cato being forced to team up in an alternate version of the Hunger Games. Maybe they realize that the Capitol's control is the real enemy and start to work together to undermine the system from within the arena.
One interesting fanfiction could be where Katniss's sister, Prim, has a secret talent for combat training that she's been hiding. This could add a whole new layer to her character, as in the original she was seen as more of a healer. Another might focus on Prim's life in District 12 before Katniss volunteers for the Hunger Games, showing her daily struggles and relationships with the other villagers.
In a darker fanfiction, Katniss could be assassinated. The Capitol, still angry about her rebellious acts, sends a highly skilled assassin. The assassin manages to infiltrate District 12 and kill her in her sleep. This would lead to a huge uprising as Katniss was seen as a symbol of hope for the districts.
If Katniss never volunteered, the entire story dynamic would change. The other tribute selected might not have had her survival skills or determination.