Forget robots, or space travel, or monsters from the deep: The child soldier is one of the most chilling, compelling tropes that dystopian fiction can employ. The idea of children forced into combat has made its way into a wide range of popular tales ranging from Ender's Game (whose film adaptation opens in theaters this weekend) to The Hunger Games and even The Walking Dead. Of course, it's also a phenomenon that is quite real; according to statistics quoted by the United Nations, nearly a quarter of a million children throughout the world are classified as "child soldiers" and have been employed in almost every global conflict since the year 2000. Although the fictional portrayal of child soldiers takes many forms, from deserted islands to battle-domes, the way we confront the topic in literature can serve as a futuristic, speculative mirror for the way we understand youth, power, morality, civilization and war -- and how the phenomenon of child soldiers can affect individuals, societies and the world for generations to come. Spoilers follow. Above: Ender’s Game series Type of media: Original novel series by Orson Scott Card, adapted comics, adapted 2013 film Why its child protagonists are violent: In the future, humankind is at war with an alien species called "buggers," whom the government says will destroy all humans if given the chance. Children are summoned by the militarized government to receive military training at an early age, and told it is their duty to prevent the extinction of the entire human race. Issues it tackles by using kids instead of adults: The Battle and Command Schools, the two levels of military training academy children attend in order to learn how to properly defend Earth, embody the priorities of Ender’s world. Not only is the government incredibly strict about population control on Earth (as in China today, Ender’s world maintains a two-child law), but it also preys on civilian families like the Wiggins to literally breed children for the global military. Ender’s insecurities and fears as the youngest sibling, as a rare third child, and as an ostracized genius – make him earnest, resilient, unexpectedly brilliant, and above all pliable, qualities far more common in children. Why it's effective: That Ender could be tricked into believing a real battle scenario was a game-like video simulation is one of the most believable post-modern twists in modern science fiction, particularly considering how often the difference between our digital and "real" lives is debated and conflated. Ender becomes a "hero" in a supposed video game, something that embodies and magnifies fears about video games, both in 1985 when the book was published and today. As is often the case in dystopian fiction starring young people, we see ourselves in Ender, a pawn whose "free will" is molded to fit the objectives of a larger cause we take on faith, because we fear the unknown and because we have no choice. (Ender could also be viewed as a stand-in for any fresh-faced young soldier, child or no, unknowingly compelled to commit atrocious acts.) The horror lies in the ability of the manipulative Command School authorities to seamlessly translate Ender’s fears and frustrations as a tiny yet brilliant child into full-scale ammunition against a political and military threat. It's a narrative that perfectly encapsulates why militarism and xenophobia are so catastrophic, especially when it involves the use of children, however brilliant or adult they seem. —DEVON MALONEY

The Walking Dead Type of media: comics series, adapted 2010 television series Why its child protagonists are violent: Like many real-life child soldiers, kids in the Walking Dead are often forced into witnessing and committing acts of terrible violence because the only alternative is death – either at the hands of zombies, or other survivors in a world where civilization has collapsed. While some children are insulated from by adult protectors or sealed enclaves like the prison, the fact that any form of death – even natural causes – turns people into undead monsters means that safety is always temporary. Imagine a war zone where even your loved ones can turn into a murderous enemy at a moment’s notice, and the difference between life and death depends on whether you can turn on a dime and shoot them in the head. Issues it tackles by using kids instead of adults: Again, much like real-life child soldiers, Rick's adolescent son Carl highlights the moral damage of war – a time when traditional morality is often suspended – by juxtaposing it with childhood, a developmental period where children are typically protected from the harsher realities of life. In Season 3, we see The Governor – the nefarious leader of the seemingly idyllic gated community of Woodbury – dismiss the modern notion of childhood as he recruits soldiers for his army: Governor: And if we include the men and women, ages 13 and up? Milton: Don't you mean boys and girls? Governor: Adolescence is a 20th century invention. Men and women. Although Carl begins the television series a shy and sheltered young boy, he quickly transforms into a seasoned killer first of zombies, and later of people. He not only shoots Shane, his erstwhile surrogate father, to protect Rick, but is also forced to shoot his mother in the head when she dies in childbirth to prevent her from turning. Towards the end of Season 3, he even kills a member of an enemy force who appears to be surrendering; when his father objects, Carl says that they’ve let threats to their community live far too often, with lethal results. As amoral as it seems, it’s hard to argue with his pragmatism after seeing how many people have died for the sin of mercy. Although a horrified Rick briefly takes away Carl’s gun, when a deadly flu causes a zombie outbreak in the prison, Rick gives the gun back – a recognition not only that he is unable to protect his son from horrors of the world, but that doing so might leave him even more vulnerable. Why it's effective: The Walking Dead is a series about survival horror, and often that horror comes from the things that people do in order to survive. Faced with a world where the unimaginable is asked of survivors on a daily basis, killing becomes a form of pragmatism, and failure to kill a potentially fatal form of weakness. Modern civilization often looks back at the past and finds it barbaric or cruel. But when Rick – and the audience – look at Carl, we see that same brutality not in humanity’s past, but in the face of its future. Carl represents not only the death of childhood in a world where innocence is a liability, but moral regression: how the necessary ruthlessness of survivors like Carl will shape the next generation of humanity, and perhaps generations to come. –LAURA HUDSON

Battle Royale Type of media: Novel by Koushun Takami, adapted manga series, adapted 2000 film (streaming in full on YouTube, above) Why its child protagonists are violent: Mandated by an alternate-timeline Japanese government (now a part of the Republic of Greater East Asia), 42 9th-grade children must battle to the death in accordance with a law called the Millenium Educational Reform Act. The law is meant to keep people from lashing out against the RGEA’s fascist super-government, though in the 2000 film version, little attention is paid to the outside world watching the battle. It becomes more of a punishment of youth and adolescence – and the disrespect of elders – far more than any perceived future threat to the government. Issues it tackles by using kids instead of adults: In Battle Royale, the focus on children forced into combat seems to be less universal than most instances of the child-soldier trope, instead placing 14-year-olds in vicious scenarios to highlight the brutish, terrifying nature of coming of age in increasingly uncertain times. Why it's effective: Battle Royale uses an extreme, dystopian-fascist setting to pit Japan's cultural traditions of respect and filial piety against the unknown variables and fears of the future. The characters’ moments of innocence – when Yukie Utsumi tells Shuya Nanahara, giggling, that she had never touched a boy before wrapping up his injuries – endear the characters to us, forcing us to remember the innocence being ripped from them. It’s also a strong metaphor for the hellish, familiar business of coming of age at the turn of the century (the book was published in 1999), when uncertainty and terror about the future was – and continues to be – a transfixing theme. The film's overall takeaway? Fascism is bad, but so is everything else. Welcome to the real world, kids, and despair. --DEVON MALONEY

Neon Genesis Evangelion (and spinoff series) Type of media: Animated series (and assorted spinoffs) Why its child protagonists are violent: When monstrous angels invade the world, the children of Evangelion are recruited to pilot the giant cyborg Evangelion units against them. Most are reluctant soldiers, recruited just as reluctantly by their adult supervisors. Whether Evangelions can only be piloted by children in general or these specific children in particular remains ambiguous throughout; all of the children have specific ties to the Evas they pilot but are referred to on and off as part of a larger pool of pilot candidates. Issues it tackles by using kids instead of adults: The child soldiers of Evangelion are a fairly direct embodiment of the "kids are our future" axiom: By accident of biology or design, they're the only ones capable of piloting the only devices capable of staving off Armageddon. Why it's effective: Evangelion derives a lot of its emotional and thematic resonance from parent/child relationships and power dynamics and the fragility and fluidity of adolescent identity – neither of which would play nearly as effectively with adult protagonists. The children of Evangelion are recruited and sent into battle out of sheer necessity, underscoring the desperate extremity the war has reached. From a tactical angle, the children's age has become irrelevant: All that matters is that they alone are capable of giving humanity a fighting chance at survival. –RACHEL EDIDIN

The Hunger Games Trilogy Type of media: Book trilogy, adapted films Why its child protagonists are violent: Much like Battle Royale (which many Royale loyalists fiercely claim was author Suzanne Collins’ source material), the underage bloodshed in The Hunger Games is mandated by an all-powerful government situated in the Capitol, the center of a 12-district future North America called Panem. The government, led by stone-hearted, megalomaniacal psychopath President Snow, employs the annual games as an institutional cornerstone of the nation’s entire socioeconomic (rather than just political, as in Battle Royale) structure, orchestrated to keep its inner-district one-percenters rich and happy, while its wretched, starving outer-district populace produces the resources they require. Issues it tackles by using kids instead of adults: Children symbolize hope in Panem, and their widely celebrated murder – and the fear that one day your child could be selected – is a symbolic form of crushing it. Unlike Battle Royale, however, the Games use children less to menace a nation’s youth and far more as a power play against the adults of Panem – their parents and communities. Of course children are terrorized by the concept of being chosen, as well, but their suffering is coercively broadcast across the mostly impoverished districts of the nation, in order to traumatize everyone (or entertain them, if they’re the rich, gullible sadists of the inner districts). Why it's effective: The use of children, Katniss in particular, helps engage a younger audience, and does so with a resilient, capable, adolescent female protagonist – a rare thing indeed in most dystopian tales. It's obvious why young readers engage with young protagonists (okay, Katniss at 16 isn’t exactly a child, per se, but Prim and Rue are 12), but even adults can identify with those children in hyper-violent situations, because they confront a strange, terrifying new world with the same adolescent uncertainty that someone like Katniss or Peeta would. It’s both relatable and heartbreaking, in other words: the perfect setting for a young-adult dystopian narrative to communicate its commentary on the barbarism of totalitarianism and exploitation of the working class. –DEVON MALONEY

Lord of the Flies Type of media: Novel, adapted 1990 film (streaming in full on YouTube, above) Why its child protagonists are violent: During a nameless war, a group of British schoolchildren are marooned on an uninhabited island. At first, they try to establish a structured and peaceful civilization, but more violent factions quickly rise to the fore, propelled by superstition and brutal tribalism. Issues it tackles by using kids instead of adults: At its heart, Lord of the Flies is an allegorical examination of the tension between humans' drives toward chaos and civilization, compassion and brutality. Children are treated as relative tabula rasa, whose true brutal natures exist under a fairly thin veneer of social rules and, bereft of those rules and structures, rise quickly to the surface. Why it's effective: Most kids read Lord of the Flies at some point during junior high or high school, ages when the petty cruelty and social conflicts of your peers sometimes seem an awfully short leap from the life-or-death conflicts of the kids on the island. At that point, Jack, Ralph, Simon, Piggy, and the rest aren't just allegorical vehicles; they're the people you know (and are). The generational contrast at the end of the book is bleaker still. The boys are rescued by a Naval officer, an embodiment of civilization and order – who will return them to a world embroiled in violence on a far larger scale, within the auspices of civilized society. –RACHEL EDIDIN