KATNISS: It's a mockingjay pin. To protect you. And as long as you have it, nothing bad will happen to you. Okay? I promise.
It's a beautiful thought, though it doesn't quite work for Prim. For Katniss, however? That symbol might just have given her the hope she needs to survive all of this.
KATNISS: Prim. Listen. You're gonna be okay. Don't take any extra food from them. It isn't worth putting your name in more times. Okay? Listen, Prim. Gale will bring you game. You can sell cheese from your goat.
PRIM: Just try to win. Maybe you can.
KATNISS: Of course. And maybe I can. I am smart you know.
PRIM: And you can hunt.
Katniss's world has just ended, and she's more concerned about Prim's survival. That actually bodes well for Katniss in the arena; it's her own motivation to survive.
KATNISS: There's 24 of us, Gale. Only one comes out.
GALE: Yeah, and it's gonna be you.
Here's a real buddy: telling Katniss that she can emerge triumphant, even if the odds are most decidedly not in her favor.
CAESAR: And this moment here, this moment is a moment that you never forget. The moment when a Tribute becomes a victor.
Or, in other words, the moment one teenager bludgeons another teenager to death with a brick. Survival in this world is presented as a great triumph, even though the whole contest is basically an exercise in sadism for no purpose other than to entertain people.
HAYMITCH: When you're in the middle of the Games and you're starving or freezing, some water, a knife, or even some matches can mean the difference between life and death. And those things only come from sponsors. And to get sponsors, you have to make people like you.
Survival in the Games means more than just building a fire or fighting the other Tributes. It means making a good impression on television; in order words, being a celebrity.
KATNISS: You fed me once.
PEETA: I think about that all the time. How I tossed you that bread.
One of the reasons that Katniss, and to a certain extent Peeta, do well in the Games is that they're already used to fighting for survival. That's something the District 1 Careers may not have had to do.
KATNISS: I told her that I would try to win. That I would try to win for her.
CAESAR: Of course you did. And try you will.
Caesar condescendingly says "try," then doesn't go any further. This is one of the few points where Caesar and the government he represents acknowledge that 23 of their 24 Tributes aren't going to survive.
SNOW: (to Crane) I like you. Be careful.
As we learn at the end, survival in Panem is never guaranteed, even if you're literally running the show.
THRESH: Just this one time, Twelve. For Rue.
Thresh lets Katniss live. Why? Because Katniss protected Rue (who was from his District), which suggests that mercy and compassion can be survival tools as well.
PEETA: She saved my life.
KATNISS: We saved each other.
Another case where being a decent human being means having someone to watch your back and, in return, having the strength to survive.