The plot takes place after the events of New Vegas with Mr House victorious and you as his loutenant, soon after the Chinese reemerge in the Wasteland with a large invasion on the west coast taking NCR by surprise, Mr. House calculated the inevitable fall of NCR but is reluctant to send his robot army to assist the NCR as it would leave NV weak against the Legion Remnants and the lack of trust in NCR as they might try to take over NV again after the war, so eventually Mr. House and you decide to send yourself, his trousted loutenant to alone assist NCR, the most large and powerfull enough force on the west coast to repell the Post-War Chinese communists.
Mr. House knows that the NCR is the only buffer power on the west coast and the only sacrificial lamb in the worst case needed to prevent the Chinese from setting a foothold into the Post War United States of America.
The Courier, now a Loutenant and personal right hand of Mr. House is sent towards NCR as a New Vegas representant and atache against the Chinese forces. The Courier may take companions from NV or may go alone and possinly meet new ones along the way. Companions like Lily or Boone would be eager to join you.
THe Courier finds deserted NCR outposts near NV, all forces that could be spared were redirected to more vital fronts with the invasion ensuing. Inevitably the Courier will link the NCR and face first hand the Chinese Forces as they march deeper into NCR.
By that time the Courier reaches NCR, the Boneyard will be besieged and near taken, the Courier can start to travel and test\harras and attempt to reinforce Dayglow, The Hub or the State of Maxon which are being hard hit. Chinese forces also had many infiltrators in many other settlements and several special small forces of Chinese Forces have been sent to harras deeper NCR settlements, a thing the NCR hadn't predicted resulting in many severe blows and even having smaller settlements and outposts destroyed and taken.
Junktown finds itself trying to fend off several smaller detachements of Chinese forces that had marked the junky town as a rallying point for the small inside border harrasing forces, which all threaten to overwhelm the town as the detachements gather around it.
Navarro now clings desperately from bleeding to much, the higher ups deciding to send massive reinforcements there to prevent the chinese from atacking deeper norther Californian settlements. Their situation is dire as the chinese instead of taking the somewhat fortified shore base decided simply to go around it and go directly to deeper parts of the NCR all the while harrasing and bleeding Navarro to a ripe fruit to be taken eventually and aplying hit-and-run tactics dealing damaging losses to the NCR forces in route to Navarro. As such Klamath is soon taken and the Den barely hangs to a string. The Chinese go as far as harrasing Modoc and Redding. New Arroyo and Vault city not yet into the party had only had to deal with a few far scouts but do not feel at all comfortable with this threat closing by. As such secret Vault City and Remnant Brotherhood of Steel relations openly come out of secrecy as the two declare a permanent new alliance to each other for the development and the security of their people, all while the NCR barons, senators, congresmen and president rage like pigs against their action but permitting it as their forces are tied to the invasion.
New Arroyo while mobilizing it's forces in full becomes the new home for the Followers of the Apocalypse. With years of growing NCR discrimination and right before the Fall of Boneyard, the Followers decided that it's headquarters was to be evacuated, a wise decision as in less than a day after their departure the settlemet was sorrounded. They started a march to the north, being ill welcomed at the Hub and out right rejected to enter it's capital doors at Shady Sands, the Followers decided on a desperate exodus to their small New Arroyo outpost as the Chinese Forces always seamed to be a step behind them. The New Arroyo people welcomed and accepted them with open arms even with the posibility of a small resource stretch on their part.
NCR besides having been dealth a devastating surprise blow by the sudden invasion and having their supply,communication and traveling lines severely interrupted by Chinese Infiltrators and Small detachements, the state of the NCR itself at the point of invasion was against it. The NCR has been fighting successive wars with the Raiders, Enclave, The Brotherhood and Caesar's Legion that had bled the NCR of it's men and resources along the years despite their ever more imperialistic growth.
--End of Tactical Situation.
The Courier soon learns that it's help alone won't be enough to get the NCR out of the gutter hole and is driven to northen lands to convince the fresh New Alliance between Vault City, Gecho and the Brotherhood of Steel Remnants and possibly New Arroyo. The New Alliance is higly trained and very well equipped with modern and quality weaponary and with advanced combat armors and Power Armors and have plenty of medicine to provide for every one of their men. New Arroyo is now quite a large and bustling settlement with a very long range scouts and good trained troops with decent armor and weaponary.
The Courier absolutely needs the assistance of the New Alliance for any hope of saving the NCR and repelling the Chinese, while New Arroyo is not vital for the war but it's assistance would be very helpfull to the war effort.
If one or either of them are convince then they will assist the Courier with their already mobilized forces in aiding Modoc and Redding and liberating the Den and Klamath, essentially relieving the stress along the Arroyo-Alliance sphere of influence.
Meanwhile as the chinese weren't enough of a threat the lack of enough troops in New Reno sparks a civil war among the gangs and the NCR garison as martial law is set in. New Reno becomes the scene of a brutal civil war that some chinese forces find themselves entagled inside while most of the chinese are mopping the outskirts of the town waitting for the fighting to calm down and then take over.
Also in this time a large force of the Chisene ammas from San Francisco and steadily makes it's way directly to the Capital of the NCR, Shady Sands. This large movement of Chinese is aspeacilly acompanyed with heavy guns, a few tanks and a number of communist soldiers in a crude variant of Chinese Power Armor. By now the NCR desperately try to ammas forces for the capital while trying to maintain the southern integrity of the NCR which is in a horrid state of affairs.
Now The Courier along forces from Arroyo ,the New Alliance and a small NCR force march on south, repell the chinese forces around New Reno and almost raze what is left of the city in order to bring order to the chaos, few NCR troops survive from the Reno Civil War and fewer civilians do, the gangs that once inhabited this city of vice are forewer erased from the Wasteland.
The Courier and the forces he gathered continue their trek south untill they arrive near Shady Sands in the nick of time, having a few hours to spare before the Chinese thrust of the west finally hit in full force at the NCR's home steps.
Here at the outskirts the Courier finds himself meeting with some NCR forces that had been spared from southern parts, and, has the opportunity to meet with a few familiar faces if the Courier played his cards right originally in New Vegas. These familiar faces are the Fours Misfits if the Courier helped them train properly and assuring their survival in New Vegas. Now Captain Mags, Loutenant Poindexter, Sergeant Razz and O'Hanrahan, who will be more than glad to see you and even more gratefull that you are on their side. But you will also meet Commander Cassandra Moore in charge of the southern reinforcements.
If the Misfits are present then the four of them will decide to hold the atack if the Courier wants to but only for untill the middle of the battle, or else the Misfits along with their men will march on in a suicide atack to liberate the capital.
Cassandra Moore on the other hand will disregard the Courier's opinion and will charge immediately for NCR, but he can persuade the Misfits to his side and go by the Courier's plan with almost half of all the NCR forces following them. Cassandra infuriated by the Missfits choice if so will charge no matter with the other half of the NCR forces to certain doom.
Here the player has three opportunities:
The First Opportunity is to charge immediately with all the Allied forces combined to help the Capital repell the Chinese Forces with the maximum of forces gathered. This will help the capital have a more likely chance of survival.
The Seccond Opportunity will be to wait for the Chinese to completely sorround and smash the defences of the Capital and actually invading it. Letting all the barons and the corrupt senators and leaders die in the event as they gathered in what they thought was the safest place in the whole of NCR. Cassandra Moore that will had gone alone in the First Opportunity will be reppelled and sorrounded themselves for the slaughter in the process. This will somewhat put the Chinese at ease thinking this was all the reinforcements that the Capital would get, making the actual intervention a surprise atack from the Courier's forces. This choice will leave the Capital in a major ruin.
The Third and last Opportunity will kick in if the other two haven't been sellected. The Missfits that would have left for the Seccond Opportunity will also be defeated by the sheer numbers and firepower of the Chinese Forces. But this option will grant the Courier with the satisfaction of complete anihilation and massacre of the NCR capital before finaly liberating the rubble.
At this point at choosing how to liberate the capital of Shady Sands the Courier might get a message from Mr House coordonating with the Boomers who are ready for another test flight of their packed full bomber with major ordonances heading for Shady Sands, along with a repaired airplane from the McCarran Airport by the Boomers who are heading to the outskirts to Vault 15 with some vital war supplies, a few sentry robots and securitrons for the Courier's personal use.
After the Courier decides how to handle Shady Sands the march of the combined forces continues westwords toward San Francisco, the main settlement and base for Chinese operations.
This march will cut in half the chinese forces in the south running almost rampant and those in the north being squeezed with a tightening grip.
With the march and the settlements in the north secure the chinese there being deterred and outgunned decide in an angry manner to finally mobilize all it's forces in the area and completely overrun the NCR Navarro, ironicly as the NCR did when it was under Enclave banner. There they staged a minor base while most of the forces headed south to greet the Courier's Ragged Tagged Alliance heading to San Francisco.
Eventually San Francisco is taken with the help or not of the original chinese population which the Courier may persuade relatively easilly against their communist counterparts, and capturing some of their major vessels still in the port.
From there on it becomes a mop up operation with the coast, trapping the remainning chinese forces in the mainland and dealing with them step by step by the Allied forces though NCR receive the most cripling and devastating blows south of their capital.
The major factions of the plot are: 1-The New California Republic, 2-The Alliance of Vault City & Remnant BOS (and Vault City's old ally Gecho) , 3-The Invading Chinese forces.
Other Factions will be: The Followers of the Apocalypse, The Boomers, New Arroyo, Mr. House.
The plot\game Endings:
1.NCR-The Disintegration of the NCR as many of it's states and cities are either destroyed or later decide to cecede from the NCR or join the new Alliance. (Happens if you decide to delay them assistance intentionally, crippling the NCR for decades to come)
2.NCR-Battered and Bruised but still Standing, The NCR came out from the war in a bad shape but still standing, the new leaders and gouverment almost unanimously decide to gouvern the NCR the way Tandi did, growing slow & steady only as much as they can permit securing and providing for everyone, less imperialistic. (Letting key figures die, and keeping some key figures alive and delaying assistance only for a very short while)
3.NCR-Battered & Out for More, The NCR comes out the least battered and remains with the same imperialistic and selfish agenda. Nevertheless Vegas continues to have a good influx of clients.
The Vault City & BoS Alliance
1.Vault City & BoS form a new united power in the wasteland including VC, some BoS Bunkers, Gecko and New Arroyo and soon many other. After NCR emerged severely crippled the new alliance quickly put up a policy to deter NCR ever going back again on it's feet by negating trade or putting it against their advantage, many new cities and villages close to the alliance cecede the NCR and join the Alliance as it emerges as the new stable power overshadowing the NCR. (If the NCR emerges in the worst state)
2.Vault City & BoS form a new united power in the wasteland including VC, some BoS Bunkers, Gechk and New Arroyo, they maintain cautious but good relations with the NCR as the Alliance emerges as a new power in the wasteland with some of the former settlements that have been liberated from the chinese joinning the new advanced and stable power.
(If the NCR comes out Battered but Standing)
3. Vault City & BoS form a new united power in the wasteland including VS, some BoS Bunkers, Gecko and possibly New Arroyo. After the chinese are defeated the Alliance is ever looking over it's shoulder over it's NCR neighbour, always weary of a new possible invasion from their side, nevertheless the Alliance steadily grows and becomes a balancing power against the Imperialistic NCR. (If NCR emerges the least battered)
Shady Sands, the capital of the NCR itself can end in 3 ways:
1-Shady Sands Overwhelmed and later Razed to the ground in the face of the NCR cavalry and the Alliance forces. Almost nothing and no one remains of the Capital of the NCR as the Chinese quickly implemented a scorched Earth policy in front of the advancing Alliance and NCR forces. (Don't help NCR organise it's forces, held back the Alliance forces, step in at the last moment after the capital is completely taken over)
2-Shady Sands Overwhelmed and quickly Liberated by the Alliance Forces ,NCR reinforcements & The Courier. The Capital emerges severely ransacked and destroyed after it's liberation, a mere sad and pathetic shadow of what it once was. (Delay the reinforcements untill the Chinese forces breaks into Shady Sands and then send the cavarly in)
3.-Shady Sands stands firmly against the Communist Threat! A sturdy defence is put on that breaks the spier head of the Communist Forces, the outer walls and defences crack but the assault eventually stalls and is broken off, Shady Sands forces ammas and later prepares to march on to San Francisco while dealing with the few pockets of infiltrators left inside the capital. The capital remains largely intact. (Organize the defence of the capital and the battle plan the most efficient way)
New Arroyo, one of the most advances and prosperous settlements of the wasteland:
1.-New Arroyo is convinced to ally itself with the new Vault City & BoS alliance
2.-New Arroyo takes part in the war BUT remains neutral.
Mr. House ending speech:
1.-Mr House is displeased that the NCR is almost but destroyed as it will cripple New Vegas financially but pleased that a new avenue from the New Alliance will be oppened. (If NCR is in the worst state)
2.-Mr House is most pleased at the outcome of the war as the Courier surpasses even House's most acurate predictions. With a stable and less imperialistic NCR and the emergence of the New Alliance trade and the influx of tourists will be on the rise. This is the most beneficial ending for New Vegas. (If NCR comes Battered but Standing)
3.Mr House is pleased with the result of the war even though NCR remains a selfish imperialistic power, as the New Alliance rises as a stabilizer in the region. Relations with NCR continue as New Vegas signs several treaties of trade and security in case NCR decides to make a hostile move on either of them.
(If NCR comes out the least battered)
San Francisco reluntactly joined their bretheren in the war, and their outcome can be:
1.-San Franciso comes under NCR-Alliance rule, later the call for independence from the City's population result in the peacefull ousting of the NCR as it is in no major condition to keep a tight controll on the city and it's people, but a small force of the Alliance remains in the original BoS outpost as several agreements of cooperation and development are signed between San Francisco and the new Alliance. (NCR is nearly destroyed)
2.-San Francisco remains for some time under NCR-Alliance rule after which the city is granted it's independence through peacefull means, it maintains shy but good relations with both factions. (NCR is battered but still stands)
3.-San Francisco is annexed, and abused by NCR forces for years to come, the Alliance small garison and base at the old BoS bunker stay neutral and defiant of the NCR. As time passes San Francisco plunges more and more into a civil war against the brutish and imperialistic NCR presence.
(NCR comes out the least battered)