Let's get a couple things straight:

-Logistically his Securitron army is a powerhouse. Yes, pulse weapons could potentially provide an Achilles' Heel, but that's a question of actually applying that many on such a grand scale. The only individual who would seem capable of manufacturing a mass-scale pulse weapon is the Courier, who has direct access and free service from the Think Tank.

-The Hoover Dam is without a doubt one of the single most valuable pre-war commodities in existence. The Great War began due to a scarcity of resources, thus meaning that cleaner renewable energies would be more valuable. The Hoover Dam is the 6th largest hydroelectric dam within the United States; the only source of clean water and electricity that would dwarf it's output would be if all three major dams built upon the Columbia river to the north (Washington and Oregon) are still fully functional (questionable, remember Vegas is largely intact due to House, though it's also true the NCR is largely responsible for getting it back up and running to the degree that it is) and if one faction could manage to capture and control all three. The Hoover Dam virtually solves all issues of water and power demand that any other nation would struggle with.

-Currently and if the case were to be that House were canon (thus meaning an NCR and Legion defeat alongside the Courier's support for House), there are absolutely zero superpowers within the Core Region proper that could directly and immediately oppose House. The closest potential threat would be the Midwestern Brotherhood, of which we know very little and even that seems farfetched since the Midwestern BoS is also assumed to be busy fighting (and partially losing to) the Legion on the Legion's eastern front. (the source for this being that the Legion has experience fighting the Brotherhood and the only known case of the Brotherhood existing within the Legion's vicinity is the Midwestern chapter)

Specifically naming House and not Indy despite the two sharing similar traits simply because Indy is less likely and less capable of expanding. Both could do a fantastic job of defending their borders, but Indy would struggle to organize and expand whereas House would not.

I bring this up mostly because in the past, we've argued about which ending is likely canon, and in the past we've argued why this or that nation should be the victor. Now I'm sort of past the "I would like this nation to be the victor" and more focused on the "which nation seems most logically implied by the storyline to be the victor." As an example I've recently played a female character - something I rarely do - and talked to Red Lucy. Sure enough, the way to initiate Bleed Me Dry was to hit on her. In the past there have also been discussions about if the canon Courier could possibly be female, which is something I've always found unlikely (both because of the target demographic for this game and because a female Courier sort of downplays the drama of the storyline by making the Legion a semi-non-viable or realistic option for the Courier), but that little snippet just further reinforced my belief that the canon Courier will of course be male as it matches with the storyline and makes more sense within gameplay. Sorry to any feminists or people who'd like to see a change of pace from the caucasian male protagonist pattern. Maybe next time; after all, the Courier was the first to break the heavy armor + dog companion + good karma trope (unless you count the Warrior from Tactics, as the default character iirc was African American).

To me, Indy still feels like the most implied ending with House taking a close second and an ambiguous Indy-or-House ending feeling VERY plausible (aka it's revealed Vegas is now under independent control, but isn't clear by who). The biggest thing working against a House ending, to me, is simply that it's TOO perfect. Too perfect in the sense that there's no plausible or realistic conflict against a Vegas controlled by House in the future (who could possibly oppose it) and so long as it's running and stable, we'd presumably see a steady rise in technology present in the post-apocalypse. With Bethesda making an awkwardly scientifically inaccurate post-apocalyptic FO3 game 200 years after the apocalypse and Avellone and Sawyer of Obsidian in disagreement about just how advanced and civilized society should be allowed to become, this seems unlikely.

My questions are basically this:

1) What could ever possibly hope to oppose a House-controlled Vegas. Assume that every major faction we've encountered suddenly went into a mass-scale war: how could House POSSIBLY lose?

2) Do you think it'd be interesting to see a House-controlled Vegas as a major player in future post-apocalyptic politics of the US?

I ask because I'm entirely 50-50 on it. I do think it could potentially be interesting, but at the same time I struggle to see how on earth a House loss or struggle could possibly arise in future titles, thus meaning a House canon ending = House wins forever, which would surely grow stale.

I'd also like to welcome anyone who would like to argue an NCR or Legion ending would be more ideal as I'm somewhat inclined to agree. I think a Legion ending would actually be incredibly interesting and spark all sorts of new potential conflict for the Fallout universe as a whole; I simply feel as though a Legion ending is the least likely of the four simply because of how overwhelmingly unpopular they are.

Well House wouldn't really do well in a full-scale war.

Humans can be replaced and produced more easily then securitrons. Maybe securitrons don't need food or water, but they still need ammo to be supplied to them.

Vegas has...casinos and the electricity to power those casinos. There's not much industry or infrastructure beyond that.

House can't employ the Legion's tactics of terror and infiltration.

The NCR does have vehicles and aircraft. It's not going to be a case of poorly trained grunts vs super robots. The NCR can bring in some big guns. I'd also wager that the NCR could scraqe together at least some suits of working Power armour.

House's economy relies on the NCR. They can blockade Vegas.

The Boomers can help with a single B-52. That can be shot down and when it does, it's gone.

I just can't see House winning an actual war with the NCR.

As for the second part, I'd rather the uncertainty and unpredictability of Independent over anything. Legion would be my second choice, as that would provide a very interesting scenario post-hoover dam.

I'd feel that if House won and he stuck to his vision of not-expanding, that the whole conflict in the Mojave would seem relatively minor in the American wasteland. Similar situation with the NCR.

The Legion winning would have major consequences and Indy can go either way. The writers have much more freedom with Independent then the other three.

Some of those I agree with, some I don't.

The NCR surely is (on the whole and on average) incompetent, but surely it'd occur to one of them that a sanction against New Vegas would be more devistating than any possible military action. The real struggle there would be maintaining stability within the NCR to an extent that people don't just rebel and go there ANYWAYS, seeing as how House can cut off electricity and water to the NCR in response. Still, it is worth mention that while House would have the water and electricity, NCR has the food. The only community within the Mojave proper that's responsible for a significant amount of food production is the Boomers or Westside; everyone else only produces enough to feed themselves, with Freeside and the Strip being complete leeches on this front.

As for the Securitrons being difficult to replace or expensive to keep in shape? That I doubt. They have on-board auto-repair systems and there's no reason to believe they're more taxing on ammo than any common grunt. Likewise with the Boomers on their side, a potential weakness for snipers (Securitrons have respectable range, but cannot snipe) is negated simply with artillery.

And surely any expansionist campaigns by House would be slow. I both trust and distrust House when he says he has no interest in expanding. Trust because I have no reason to not take him at his word, especially given that he opted only to save New Vegas in the past, distrust because I have enough of an understanding of economics to realize that a capitalist nation will, by design, only grow and not shrink, which will eventually lead to expansion. How he'd expand would be a bit more difficult as his securitrons would have somewhat limited range. (we can assume that by the end of New Vegas they can travel the Mojave proper without issue, but actually invading Arizona or California? Nah, that seems problematic).

Even so, he creates a massive plot issue for the Fallout Universe merely by existing. I do believe House's ambitions towards space exploration are sincere. Go to Repconn headquarters, take the guided tour and mind that House owned Repconn at this time. It seems clear to me that the man has as much of a fascination with space as he does with snowglobes. So even if he stalemated but kept his own homefront intact, the post-apocalypse as a whole is benefiting from it because the man is fixated on ambitious technologies.

As I said, I'm 50-50. It's not even a matter of having a personal grudge or issue with a House ending (I'd personally enjoy it), but more a matter of I can't realistically see how it's plausible without tremendous implications for the entirety of the Fallout universe; implications that may not be desired by Bethesda/Obsidian.

And yeah, this is even MORE unlikely, but I truly believe a Legion ending would possibly be -THE- most interesting. The thing about the Legion is they're very human, fragile and mortal, and yet they survive purely by being disciplined and badass. The Legion doesn't beat the BoS by being better geared, they beat them by being faster, smarter (mind you the Legion is smarter tactically and more cunning in battle; not implying the Legion is more educated) and stronger and being absolutely bred for war. The Legion would provide a constant threat that could also die off at any moment, all while having the capacity to develop into something "better" and more civilized, as was Caesar's desire.

the NCR can be weaken without full hostility between house and them. one of cass questline will do this. when this happens, their leaders may decide to think before acting. starting a feud with house would be counter productive. a fortified house would be a buffer between the NRC and the legion.

house tends to be most interested in NV. so it is likely that the NCR could increase it borders. many NPCs think the NCR has expanded too quickly. so a slower expansion would be a asset for them.

House is extremely vulnerable in the Lucky 38. Machines have off switches, you don't have to oppose House's army in battle but a bit of espionage could dispose of house. Go up against House as a decoy, then infiltrate the Lucky 38 and power off these Securitron's.

House can only do so much, but if the war was knowledge to the guy his security would increase. But I reckon a faction like the NCR could slip through the cracks and deal with House anyway.

Civilization could be brought, by NCR or the Legion. But House controlling the Dam and the Strip, people will be independent and it what will happen next is ambiguous. If House took control, independent communities will continue to exist and possibly conflict between them may arise. A lot of possibilities. Will House be prepared to police all that? His goals aren't too expand, but to set up shop in Vegas. This just means for a more interesting New Vegas, not just two armies going at it (NCR and Legion).

House isn't Vulnerable in the Lucky 38. If someone got past the guards on the Casino Floor he would just disable the elevator. Problem solved. And that's if they manage to get inside.

The issue is that House's biggest weaknesses are all related to power: he needs electrical power or he himself will cease to function. While this is a significant weakness, from the perspective of a mass-scale war, who could possibly discover how to utilize this?

Take the Legion as an example. Let's get one thing straight: the Legion is second-to-none in warfare. They know their [censored], in and out. These guys are so good at warfare and espionage that they were able to figure out the platinum chip and how it was being delivered, while their opponents - the NCR - legitimately have no idea what it is or that it even exists throughout the course of the game. THESE GUYS are not able to figure out what House is. Caesar himself doesn't know if House is a man or a machine. If he could figure that out, Caesar is smart enough to know eliminating House would be as simple as destroying every power source in the area, but he cannot.

So if the Legion can't and Caesar can't (one of the most brilliant characters in the game and the Fallout universe), how would a nation like the Midwestern Brotherhood of Steel or a nation that lacked contact with the Mojave region (say a nation that builds up in the Dakotas or New England) possibly figure out which power stations to attack, ESPECIALLY when House potentially has not one, not two but three sources of power (Helios, El Dorado, Hoover Dam, not to mention some degree of reserve power) and at least one of those is going to be heavily, HEAVILY fortified?

And the doors open and seal everytime the Courier comes in. The Devs said that a while back, however they removed it from gameplay so players wouldnt need to open the doors of the Casino every time they wanted to get into the Lucky 38.

Edit: I don't know why people argue so much about 'massive scale wars'. House won't expand his territory outside the Vegas Region. He only has his eyes set on restoring Vegas and reigniting the technology development industries. So House would be more inclined to send tech to NCR and so on. They're arguing an EXTREMELY unlikely thing.

I don't see how House has the man power to overtake either the NCR or the Legion. He may prove more trouble than he's worth for the NCR to waste time outright invading the Strip, but there's no way to hell he has the resources or technology to send securitrons outside the range of the Mojave.

And the first battle of Hoover Damn (plus the whole evil never wins thing) already proves that the NCR will be the dominating power in the Mojave canon wise in later Fallout lore. They might decide to carry on with Mr. House, but I'm doubtful.

This being said, NCR would overtake house eventually. They're the dominating power in the West. The Enclave are dead and the NCR will win the struggle for control simply because of population count.