Blood Feud
Lewis kills the man that raped Bobby by shooting him with an arrow. Bobby and Ed couldn't be more thankful to be saved from this hell, but the irony is that Lewis has started a blood feud, "the game" as Lewis calls is is now on.
Man Trip
All of the men head into the woods in order to take a man trip down the river. The irony is that only one of the guys on the trip, Lewis desires to be a man of the mountains and prove himself able to survive. The other three just want an escape from their daily lives and that is why they say yes to this trip.
Buried
After the guys bury the man who raped Bobby they head off into the river, believing that everything will be okay now. But the irony is that immediately things get worse for them when they hit the rapids, Drew is killed, Lewis breaks his leg, and Ed has to kill a man to keep everyone safe in order to push on down the river. Their situation has only gotten dramatically worse.
Sole Opposition
After Lewis puts an arrow through the man who sexually assaulted Bobby, the four men have to decide what to do with the body and whether they are going to tell the police or not. Ironically, Drew is the only one who wants to go to the police and he ends up being the first one to be killed, literally minutes after they shove off the shore.
The Need to Kill
We see Ed earlier in the film struggle with having to choose to kill a deer, which he cannot do. Taking life is too difficult a choice for him to make. Ironically, Ed is the one who has to kill the hillbilly after Drew dies falling into the river. Ed has to do the very thing that he knows deep down he cannot do, take a life, in order to survive. And he does so by putting an arrow through the man trying to kill them. He's now become what he doesn't want to be, a murderer.
