Katniss’s main internal conflict is how far she will go to try to win the game and survive, such as pretending to love Peeta.
A person versus self conflict is an internal conflict. It is a struggle a person has with herself. It often involves decisions that are hard to make, fears, or worries.
Katniss has many internal conflicts in the book, but most of them revolve around what she is willing to do in order to participate in the spectacle of the games. She knows what people want her to do, and realizes that the longer that she plays along the more likely she is to survive.
Although being ready and willing to kill is difficult, Katniss’s main internal conflict regarding the game has to do with Peeta. Peeta surprises her when he announces to the world that he loves Katniss during his interview with Caesar.
Peeta sighs. "Well, there is this one girl. I’ve had a crush on her ever since I can remember. But I’m pretty sure she didn’t know I was alive until the reaping." (Ch. 9)
Katniss has to decide whether or not she can pretend to love Peeta. If she does, then she will get valuable public support. It could mean the difference between living and dying. This becomes clear to her when she receives help from Haymitch.
Haymitch couldn’t be sending me a clearer message. One kiss equals one pot of broth. I can almost hear his snarl. “You’re supposed to be in love, sweetheart. The boy’s dying. Give me something I can work with!” (Ch. 19)
Katniss knows that Haymitch will be able to get donations from sponsors if it looks like she is in love with Peeta. She kisses him, and plays along pretending she is in love, in order to help them both survive.
The whole thing went to the next level when it is announced that two winners can come from the same district. That was when Katniss determined that she could help Peeta without endangering her own life. As the game went on, she had to decide whether to eat the berries and kill herself to prevent having to kill him. Again, the star-crossed lovers gimmick worked, and both of them were announced winners. Despite the political implications, their lives were spared for the moment.
Katniss has complicated feelings for Peeta. She has a close friend, and possible love interest, at home: Gale. Gale is nothing like Peeta, and more like Katniss. Katniss feels like she is betraying Gale by pretending to love Peeta. At the same time, she does care about Peeta. This causes Katniss constant inner turmoil. To survive, she has to do things she never thought she would do—kill other kids, and pretend to love Peeta.