Are you a good person? Would you like to do bad things? It feels like practically every videogame released this year has some sort of good-vs-evil morality mechanic — Mass Effect 2, Red Dead Redemption, Fable 3: Let’s Hope Third Time’s The Charm, yeesh, even Mickey Freaking Mouse™ — but if you’re ready to really twist your brain into ethical knots, I recommend picking up Fallout: New Vegas. The entire Fallout franchise rests on a nifty culture-mash — Atomic Age optimism and post-apocalyptic pessimism — but over a decade after the first Fallout, that empire-in-ruins sensibility feels more compelling than ever. You’ll kill a lot of people in New Vegas — in self-defense, to punish wrongdoing, or maybe you just think their clothes would look better on you — and the game’s central genius is that every death feels like another nail in the coffin in the American Dream.

What I mean to say is that Fallout: New Vegas is addictively, rambunctiously fun. The game begins with your character, a courier carrying a mysterious package, shot and left for dead by mystery men. A kindly local doctor stitches you up. From there, the rest is up to you. The overarching narrative — Who shot you? What was in the package? — is less important than the million tangential storylines you’ll find along the way.

Let me give you an example. In one town, you meet an irate, maybe-crazy sniper, who’s posted up in the mouth of a T. Rex-shaped building. The sniper’s wife has disappeared. She was kidnapped, he claims. He wants to kill whoever was responsible. He gives you his beret and says, “Find the person responsible for my wife’s disappearance. Take them out in front of the T. Rex. Put on my beret as a signal, and I’ll shoot them.”

Now, you have several options. You can refuse. You can put on the beret, walk up to an innocent bystander and say, “Hey, there’s something you gotta see in front of the T. Rex!” You can wait until the sniper’s back is turned, shoot him in the head with your revolver, and take his sniper rifle. You can leave town forever.

Whenever I play games like this, I tend to be a Noble Completist (it’s my inescapable Catholic upbringing), so I did the neighborly thing and asked around town for information about the sniper’s wife. Everybody has a different opinion: she was a city woman not used to hard living, she was a stuck-up brat who looked down on the other citizens, she loved her husband and would never leave him, she hated her husband and probably just ran away. Eventually, you find the person responsible, and when you take them in front of the T. Rex, the sniper bullet makes their head explode in a particularly gratifying way. And this is the morally upstanding thing to do.

The game’s not perfect. The shooting system is occasionally wonky. The Xbox version has a bad tendency to freeze up, so save early and often. Sometimes, the gameplay is a little bit too anti-narrative: One of the most brilliantly sustained chapters in the game (a rocket lab infested with a god-cult of ghouls) ends with a whimper when you have to spend an extra half hour searching the Wasteland for a couple of thruster couplings.

None of these flaws are glaring. Given the scale of ambition here, they just feel like a bad episode of Sopranos, or the hundred pages that could probably be removed from every 1000-page book. They certainly don’t detract from the fun of hunting giant mutant geckos, or the brain-tickling moral ambiguity, or the simple pleasure of walking into a remote army outpost in the Nevada desert and hearing the theme song from Johnny Guitar playing on the post-apocalyptic radio. A-