EFFIE: A dramatic turn of events here in District 12. Yes, well. District 12's very first volunteer. Bring her up.
This is the first time we see fate and free will in opposition to each other. Destiny seemed to pick Prim for death in the arena (and we're pretty sure she'd be killed very quickly). But Katniss steps in and changes the plan.
PEETA: Yeah, our mentor. You're supposed to tell us how to get sponsors and give us advice.
HAYMITCH: Oh, okay. Embrace the probability of your imminent death. And know, in your heart, that there's nothing I can do to save you.
Leave it to fatalistic Haymitch to point out just how tough it is to change the outcome of the Games. Sometimes, you can make all the right choices and still lose.
HAYMITCH: He's a Career. You know what that is?
KATNISS: From District 1.
HAYMITCH: And 2. They train in a special academy until they're 18. Then they volunteer. By that point, they're pretty lethal.
Here's another example of destiny. The Careers are supposed to win. Everybody knows that. It's only through hard work that that destiny can be avoided.
SNOW: Hope. It is the only thing stronger than fear. A little hope is effective. A lot of hope is dangerous. A spark is fine, as long as it's contained.
It's a rare admission from Snow that a given situation can get out of hand regardless of how preordained it seems to be.
CAESAR: Well, I'll tell you what, Peeta. You go out there and you win this thing, and when you get home, she'll have to go out with you. Right, folks?
PEETA: Thanks, but I don't think winning's gonna help me at all.
CAESAR: And why not?
PEETA: Because she came here with me.
CAESAR: Well, that's bad luck.
PEETA: Yeah, it is.
"Bad luck" is just another word for destiny. Can you say "lose-lose situation"?
PEETA: One of us should go home. One of us has to die. They have to have their victor.
KATNISS: No. They don't. Why should they?
Here's a point where it seems like fate is against our heroes; only one of them can survive. Even though mutual suicide is pretty grim, it still represents a way they can defy that fate.
HAYMITCH: They're not happy with you.
KATNISS: Why? Because I didn't die?
HAYMITCH: Because you showed them up.
KATNISS: Well, I'm sorry it didn't go the way they planned. I'm not very happy with them either.
The Capitol tried everything to kill Katniss, but she showed them that they can't control everything. Of course, take one step back and you could argue that none of this was really a fate vs. free will situation at all; it was a reality TV game, with hundreds of decisions being made by the show runners at any given moment. Even what we think might have been an expression of free will by Katniss was being watched and manipulated by the game crew. Sometimes they let her "choices" stand; other times they blocked them.