Nobody knows who dropped the first bomb, and nobody cares. 200 years have passed since a nuclear war between the U.S. and China reduced the planet to cinders, and humanity has only one concern: survival. The fallout not only destroyed civilisation, but twisted and distorted it. Humans mutated into feral monsters, water and plants were irradiated and animals grew in ferocity. But for you, life is peachy. For the past 19 years you’ve been living with your dad in Vault 101, a nuclear fallout shelter buried deep underground on the outskirts of Washington DC.

Fallout’s one of the biggest, deepest RPGs out there. Not a role-playing fan? It’s also a brutal and accomplished FPS. It tells an incredible story across 100+ hours, but it’s also packed with Call of Duty-style set-pieces. As we type, we’re 29 hours in and have finished the main story, but the volume of worthy remaining side quests is boggling. It’s a measure of Fallout’s depth that it begins with your birth – you emerge from the womb in first-person view, with squealing and crying that you control yourself. Your vision’s blurred, but you can just about see your dad (Liam Neeson), his face obscured by a surgical mask. “Let’s see what you’ll look like when you’re all grown up”, he whispers as a nearby monitor flickers to life, displaying the game’s character creation tool.

The editor is flexible, but no matter how much you adjust the sliders your character will always look vaguely the same; handsome, slim and youthful – mercifully, your appearance has no bearing on the plot. It’s in your character’s stats and abilities that the depth of customisation lies. As you go through your youth and teenage years, you’ll shape your character via a series of clever interactive ‘minigames’. In one you flick through a toddler’s book called ‘You’re SPECIAL!’ which determines your core stats: strength, perception, endurance, charisma, intelligence, agility and luck. In another, you take an exam called the GOAT (Generalised Occupational Aptitude Test) that judges how good you’ll be at things like sneaking, using weapons, picking locks and bartering with merchants.

You’ll spend about an hour and a half in Vault 101, making friends, fighting bullies, struggling with moral decisions and completing tutorials. We won’t say exactly what happens as it’s one of the most compelling, intriguing parts of the game, but eventually you leave the confines of your lead-lined tomb and emerge blinking into the outside world. This is where Fallout 3 really begins. You’ll prickle with relief at escaping the claustrophobia of the Vault – the sun’s blinding – only for icy trepidation to take hold as your eyes adjust to the numbing desolation outside. This isn’t a game of rich forests, and lush spires, but cruel, brown open wasteland and haunting symbols of times past.