And regardless of your decision, it's more than likely that you'll piss someone off with your actions. The Capital Wasteland of Fallout 3 often felt like a disparate collection of places to visit, but the Mojave of New Vegas feels like a living, interconnected world. Settlements are generally far larger this time around, and thanks to Obsidian's attention to detail they're far easier to believe in. You'll see farmlands, watch people struggling to obtain food and medical supplies, and you'll hear people worrying over the all-out war that seems destined to kick off at any second. And as a result of these touches, you'll understand exactly why people get pissed off when you start treading on their toes, or using a plasma rifle to melt their livestock.
The game world feels like a bigger, messier place than before, but that's not the only area of expansion. Obsidian has wisely set the level cap at 30 - a 50 per cent increase on the initial limit of Fallout 3 - and though it's perfectly possible to finish the game at around level 16, after roughly 25 hours of play, the odds are that it'll take you far longer, such is the volume of things to see and do.
I've assumed that most people will be fairly familiar with the way that Fallout works. If you're a veteran of the 2008 game (or indeed the Black Isle originals) then you'll have no problems jumping straight into the action. If, on the other hand, you're a recent convert to post-apocalyptic exploration - or, heaven forbid, to the RPG genre - then you may be in for a bit of a hard time, at least in the early days. In contrast with Fallout 3's lengthy opening, New Vegas keeps the tutorials to a minimum. I've no doubt that a lot of people will be happy about this, but it's also fair to say that a few newcomers might find themselves a bit lost - at least until they've learned to be cautious, and to pick up and sell everything they can lay their hands on. Your AI opponents are a good deal tougher than in the previous game (though they don't seem any smarter), and it'll take some time before you're wielding any decent firepower.
Thankfully there are a solid number of NPC companions for you to recruit as back-up, and if you can find a buddy they'll probably look after you until you can get to grips with how everything works. Incidentally, these allies are a vast improvement on those offered by the last game: a new radial menu lets you swiftly heal them, access their inventory and adjust their tactics (although you need to be next to them to access it). Best of all you can actually talk to them this time; if you're persistent, you may even unlock a personal quest to learn a bit more about them.
In a slight concession towards more mainstream gamers, Obsidian has allowed gamers to aim down their sights when free blazing away with their guns. If you so desire, you can configure the game to use "true" iron sights - which is to say, you'll hit where you aim; Fallout 3 used invisible dice rolls to determine the fate of each shot. It's a nice addition, but I suspect that most people will stick to VATS - the mechanic that lets you freeze time and then assign a number of shots to specific targets. It's still a fun little system to use, and while it feels a bit overpowered at times, there's still plenty of satisfaction to be found in every exploding head or blown-off limb. Besides, if you find everything a bit too easy there's always the option to enable Hardcore mode - a setting designed to address a number of complaints levelled at Fallout 3.
When enabled, Hardcore forces players to regularly sleep, eat and drink water; if you fail to meet these demands, you'll suffer stat penalties - and eventually death. As an added burden, medicinal items will only restore your health over time (rather than instantly) - and if one of your limbs gets crippled, you'll be forced to find a doctor to heal. This may all sound quite brutal, but that's precisely the point. The curious thing is that it's also thoroughly enjoyable: I began my game on Hardcore with the intention of reverting to standard play after I'd had a chance to assess it, but somehow never switched back. Yes, it's annoying when you step on a mine and blow your foot off, just as you're about to explore that mysterious bunker you've stumbled across, but the rewards are worth the effort.