One of the most important themes in The Hunger Games is government oppression. Because of the limited resources and devastation left by war and ecological disasters, the government takes a strong hand in keeping the people under their power. The people have no ability to make their voices heard, and are entirely subjugated by the government. In reaction to an attempted rebellion, the government doubles down on its brutality by enforcing the annual Hunger Games, in which a pair of children from each District is forced to fight to the death on public television. The power of the government over the individual citizen is shown in harsh detail, as the people living in the Capitol live in rich comfort, taxing the districts through force to keep them from rebelling.
Another theme is individualism vs. collectivism. The government and those who support its brutality never think of the individual and human consequences of their actions; they believe the ends justify the means, no matter who is harmed in the process. When Katniss, an individual, is able to defy the Capitol, it lets the entire country know that it is possible to fight the collective. Her actions, and later her status as a figurehead for the rebellion, shows the power of individualism.
The Hunger Games is a novel about the "haves" and the "have nots" – that is, the people who have money and the people who don't. The Capitol has money. Gobs of it. While the Capitol is wealthier than all of the districts, some districts are more privileged than others, so they can train their tributes to do well in the Hunger Games – a competition they see as a way to gain glory and fame. The poor districts? Well, not much of an advantage there. District 12, Katniss's district, is an impoverished coal mining region that never stands a chance in the Games. They view the Games as a punishment that must be endured – something that robs them of their children. The novel asks you, then, to think about how money can change things for you – and change how you see the world.
One of the themes I see in "The Hunger Games" is Power. Who has the power? Well, the main source of power in The Hunger Games is clear: the totalitarian government of the Capitol. Because the Capitol holds most of the country of Panem’s wealth, the government there is able to control the people in all of the districts across Panem. The Hunger Games, then, are the ultimate display of the government’s power and were designed to warn the populace against rebellion. In the Hunger Games, the citizens of Panem become nothing more than pawns in an elaborate game of life or death. Since only one teenage contestant, or "tribute," can win, the tributes are forced to kill teens from the other districts and one from their own district. It's all symbolic of how the Capitol prevents the people in the districts from joining forces and rebelling – the Games keep the people of the districts divided and fighting among themselves. Worst of all, the government broadcasts the event live on television, reinforcing the idea that the tributes are giving their lives for little more than the entertainment of the Capitol.
Let’s not forget, though, that this book is also about ways to resist the kind of power that the Capitol represents. While the people of Panem might not have the Capitol’s money, they do have other ways of fighting back. Remember when District 12 gives Katniss their salute? Or when Katniss covers Rue’s dead body in flowers? These symbolic gestures call attention to the fact that there are actual people in the Hunger Games – real live humans, not just game pieces. In that sense, these small moments of defiance can be very powerful.
There are a few themes that can represent the Hunger Games. The easiest to see is, of course, survival. The tributes fight against each other and the elements to survive the games. And the citizens of the districts fight to survive their daily lives where. In the later books this theme continues.
A further look could focus on human rights and equality of citizens. Citizens of the Capitol have every luxury and do not have to choose tributes to fight in the games. And the districts who normally win the games are rewarded with regular supplies. Other districts, like Katniss's District 12, are constantly faced with shortages. This could be taken farther to explore different types of governments. This as well is further developed later in books. You even compare current events in the Middle East to events in the last book.