Originally thought to be fallout shelters (and functionally, they were), the Vault-Tec Vaults were actually sociological experiments with more than a hundred different specific variables. Most Vaults housed only 1000 people with enough food and supplies to sustain them until the radiation had died down enough to repopulate the planet, but there were vaults that regularly messed with the baseline; there were vaults that had 999 men and one woman, or allowed in 2000 people but only had half supplies, or had psychoactive chemicals pumped into air supply or, in the aptly named Vault 69, 999 women and only one very, very lucky man. In Vault 101, however, the doors were sealed and never opened again. No one gets in. No one gets out. This is where you will begin -- and end -- your life, never having known what was beyond the massive circular door that leads to the outside.

Remember all our talk about character customization and zipping through your childhood? This is where they come to a head: when you reach the age of 16 and are forced to take the G.O.A.T., the General Occupational Aptitude Test to determine what your job will be for the rest of your life. Pushed off to take your test by your scientist/doctor father (voiced by Liam Neeson and whose face is actually determined by what your final created face in a nice little touch), you finally get to freely roam around the little pocket of world that will be your home for the rest of your in-game life -- or at least the first hour or so of actual play time.

The first thing we noticed as we set back and watched the almost hour and a half long presentation was just how detailed the world that Bethesda created is progressing. Imagine the smattering of bottles and books that were interactive in any of the homes in Oblivion and then spread that out over the various labs and housing quarters and corridors of the Vault (which we sadly haven't been able to see in its entirety) then triple 'em. It's clear that just because the game is real-time now instead of a tile-based isometric view (though that and an over-the-shoulder Resident Evil 4-style camera are options) that the attention to detail hasn't been lost.

It's been found, really, in just trying to present a world that's alive. The whole "Radiant AI" feature of Oblivion that had the entire world doing their thang while you walked around was a nice touch, but what's the use if you don't give a shit about someone going to sleep? Here's where Fallout 3 tries to fix it. Now, the AI performs actions more around your bubble of influence. People hold conversations when you're actually around, characters will go about their routine when you're actually there. It served no purpose to have people going about their routines when you weren't there to pay attention and now Bethesda has made an effort to engage you in the world when you actually care rather than just being there passively to happen upon.

No, it's not as dynamic, but it's more interesting and that's the key. Plus, if you'd never read this, you probably wouldn't have noticed save for the fact that more seemed to be going on in the world that was decidedly less dense than Oblivion -- less dense perhaps in sheer number of characters to deal with, but more fruitful in actual occupants to observe, and that's the key. Fallout 3 isn't quite as expansive as Oblivion, but where fast stretches of forest were the norm there, here they're more densely packed, providing more to survey... y'know, for a wasteland and all.

So you created your character and you know the bits and pieces of interaction. The real story will start once you've gleaned enough info to hack (or bypass depending on how you've made your leading guy or lady) the terminal that open the forbidden door to the outside world. See, one day you wake up just like normal, go head out to do your job like normal and maybe take a break to see dear ol' dad... like normal. Except dad isn't there. Dad isn't anywhere, and given that nobody leaves the Vault and it's generally fairly swell without a rash of random homicide, there's only one place dad could have gone.