So I’ll confess: watching Planet Earth turns me into a nervous wreck. I know a lot of people like to get buzzed and watch the ducks cruise the mountains in high-def, but when I watch the show, all I see is the killing. The fox with the gosling in its jaws. The harlequin shrimp dragging a starfish into their lair to feed on it for days. Yes, I knew that nature's a little Darwinian, but when you watch it hour after hour you realise what it means when the fittest and the luckiest survive. There is no right or wrong: the winner’s just the one who didn’t get eaten.

That lesson came back to me when I finished the single-player campaign of Modern Warfare 2. (And warning: spoilers follow.) The game’s making people squeamish. It forces us into situations that shock our sensibilities and offend our morals. There’s the scene where you pretend to be a terrorist and gun down the civilians in an airport, and then there’s the time you helped a grizzled old Brit set off a nuke, killing tens of thousands. You even take out the International Space Station! The game’s script is so sketchy and its spectacles so disconnected that most people can’t see any sense in it, and I didn’t either – until I got to the end.

In the last act, Captain Price has been betrayed by General Shephard, so he sets out to kill him. Thing is, he’s not just out for revenge; as he explains through clenched jaw, he has to kill Shephard or else the truth of what happened will never come out. “History is written by the victors,” Price declaims, and he means it in the most primal way: It all comes down to Price and Shephard grappling in the desert like beasts at the rut, fighting to see whose seed will survive.

That’s when I realised, Modern Warfare 2 didn’t muddle its morals: the game has no morals. It’s an exercise in nihilism, where survival goes to the fittest.

Okay, okay, I know that sounds bleak. So before I sound like that dour kid at school who kept quoting Nietszche at you, let me find a mellower example: it’s kind of like sports. Two sides go in, one side wins, and nobody but the fans talks about “good guys” or “bad guys”: you play the game and somebody wins. That was good enough for Pong, but we’ve moved from these simple competitions to intricate narratives that are loaded with handwringing and dilemmas and realistic scenarios, but that really just want to tell a story where one bunch of guys mows down another bunch of guys.

Other games reveal the same reservations. Fallout 3 opens and closes with the quote, “war never changes” – which sounded kinda wifty the first time I played the game, but makes more sense when you see that war is natural to games: people just keep shooting each other, and the computer just keeps score. Rockstar’s Bully likewise tried to set up the protagonist as a hero, or at least an anti-hero, but in the end, he seems like the same kind of pimply, self-centered jerk as everyone else in the cast: he’s just better at it. Oh, and the school’s motto? “CANIS CANEM EDIT.”

Even in the goofy, cartoony Spore, you can find yourself hunting other species to extinction – and that means killing their young, so they can’t get old enough to breed. I’m guessing the gang at Maxis threw this in because killing little baby aliens would pull at our heartstrings, but hey – this is nature. Sometimes, you have to break a few fertilised eggs.

After all these years of making realistic games, gamemakers still struggle with the fact that they want to tell the Hero’s Journey, but they’re marrying it to a football game. And the obsession with finding a moral is starting to crack. Let’s take another recent example. Dragon Age: Origins is another game about the lousy but thrilling things we have to do in wartime. BioWare has traditionally included a moral compass in its role-playing games, judging your actions on a scale from “good” to “evil”. But Dragon Age is the studio's first game to break the tradition. The sidekicks who travel with you and the allies that side with you may judge you, and your life may get easier or harder depending on how you act. But there’s no God-like narrator watching over your shoulder. Your job is to win, so you get to write history. And how you do that is only up to you.

Titles like Dragon Age have the right idea. And so do games like Madden 2010. As your protagonists become complex, so do your antagonists. Neither side “deserves” to win, and either side can do the same unspeakable stuff as the other. This makes us uncomfortable: we want to believe we’re exceptional, that we play by better rules and that’s why we’ll triumph. As well-intentioned citizens of modern democracies, we always look for the moral. But as gamers? We’re so done with it.

Chris Dahlen writes about games, music, pop, and tech. You can find him online at @savetherobot, or drop him a line at chris [at] savetherobot.com.