3. Twice as much going on
When Oblivion was being developed for the then-unfinished Xbox 360 and PS3, its designers didn't really have a firm handle on either system's capabilities or limitations. So while Oblivion was a staggering achievement, it also came with a host of minor problems, and now looks a little dated just two years after release. That won't be the case with Fallout 3, which - according to Bethesda - crams twice as much stuff onscreen as Oblivion did. There's more detail, more characters and creatures and generally more of everything, and the difference is as evident as the difference between these two screens:

Above: A landscape from The Elder Scrolls IV: Oblivion

Above: A landscape from Fallout 3

What's more, one of Oblivion's most irritating features - the interstitial loads that would briefly freeze the game when you were just walking through the countryside - are a thing of the past. You'll still be treated to brief loading screens when you're entering a dungeon or similar structure, but you won't be jarred out of the experience every five minutes as the game loads up a new set of textures.

4. More interesting places to discover
Ask yourself: When you're wandering through a virtual wilderness, do you relish the idea of stumbling onto interchangeable holes in the ground with names like "Anutwyll" and "Felgageldt Cave?" Or would you rather discover distinct, realistic locations that actually have a credible reason for being there?

During our brief time playing Fallout 3, we deviated from the obvious path (screw you, town of Megaton) and wandered around until the game announced we'd found the bombed-out ruins of Springvale Elementary School. It was inhabited by a few aggressive raiders, of course, but what left a lasting impression on us was how much it looked like a bombed-out school, right down to the weathered little desks that some little kids probably ducked and covered under during the nuclear apocalypse centuries before.

The same level of detail was present when we wandered a little further and found the Super Duper Mart, a mostly intact supermarket complete with working vending machines (which dispensed radioactive drinks) and wrecked shopping carts. Unfortunately, it had also been taken over as a haven for vicious wasteland raiders, who'd hung the mutilated corpses of the last people to mess with them out in front of the place as a warning.

As we entered the market and systematically dismembered the raiders with hot lead, we marveled at how believable the place was - even through the wreckage, squalor and darkened gloom, the Super Duper Mart was laid out just like any supermarket we've ever been to. Yes, it's to be expected, even in a game with Fallout 3's scope - but it's still a hell of a lot more fun to explore the familiar-looking ruins of American civilization than it is to delve into yet another dungeon that's nearly identical to the last one.

5. Realistic lockpicking
For would-be thieves crawling through Oblivion's cities, lockpicking quickly became second nature. This was mainly because all you needed to do was bounce a series of tumblers until you heard a tell-tale sound, which told you when each one was ready to click into place. With Fallout 3, you won't have it so easy. No, this is a modern wasteland, filled with modern locks, and daintily bouncing cylinders up and down like a shrieking ballerina just isn't going to cut it anymore.

Above: Oh man, just look at all the stuff you can unlock in this screen 

Instead, you'll have to jam a screwdriver up in there before poking around inside it with a hairpin, all while (on the console versions, anyway) using the controller's vibrations as a guide for how well you're doing. Hit the right angles with the screwdriver and pin, and you'll pop the lock - but just like in Oblivion, lockpicks are fragile, and these will break if you're not careful. Still, though - at least now there's challenge to it.

6. Actual dialogue replaces conversation wheels.
Yeah, dialogue trees aren't a revolutionary way to converse with people in games, but they at least beat the hell out of just clicking on a list of conversation topics - or worse, manipulating a big wheel that forces you to joke with, boast to, coerce and flatter someone all in one brief "conversation."

If nothing else, it's nice to be able to actually choose how you respond to another character, instead of just following a rote series of sterile questions.