Second Battle of Hoover Dam

The Second Battle of Hoover Dam is the conjectural name applied to the second offensive mounted by Caesar's Legion against New California Republic forces entrenched on Hoover Dam in 2282, as well as on the surrounding Mojave Wasteland.

Prelude
After the First Battle of Hoover Dam, Mr. House knew that as soon as either the NCR or the Legion became victorious at the Dam, they would turn their attention to New Vegas. In an attempt to stop this and allow the city remain under his control, he had Victor hire a courier to retrieve his Platinum Chip, a data storage device capable of upgrading the city's defense systems and activating a massive army of Securitrons. This would give House the ability to single-handedly crush the Legion and intimidate the NCR into a retreat. However, the leader of the Chairmen, Benny, learned of this plan and ambushed House's courier outside of Goodsprings, shooting them in the head and leaving them for dead in a shallow grave and taking the Platinum Chip, throwing House's plans into disarray.

The Courier survived, however, and began a journey to the New Vegas Strip to find Benny and get revenge, in the process learning the true purpose of the Platinum Chip and its power. The Courier was faced with the choice of either giving the Chip to House or destroying the Securitron army, or even using it to create an army of their own. The Courier's journey attracted the attention of the NCR and the Legion, both wanting such an influential individual on their side. Also in preparation, the Courier traveled the land looking for other tribes and factions to ally with.

New California Republic

 * General Lee Oliver, commander of the Mojave Campaign (Dam)
 * Colonel Cassandra Moore, commander of the Hoover Dam (Dam)
 * Chief Hanlon, commander of the NCR Rangers (Dam)
 * NCR Ranger Veteran Commander, commander of Ranger Alpha Squad (Dam)
 * Colonel James Hsu, commander of Camp McCarran (McCarran)

Troops

 * New California Republic Army troopers equipped with basic armor, frag grenades, combat knives and a firearm (.308 sniper rifle, 12.7mm pistol, Marksman carbine, assault carbine, riot shotgun)
 * New California Republic Army heavy infantry equipped with NCR salvaged power armor, a super sledgehammer and a heavy weapon (hunting rifle, missile launcher, flamer, heavy incinerator, light machine gun or minigun)
 * New California Republic Rangers equipped with NCR Ranger patrol armor and a long range rifle (.308 sniper rifle, hunting rifle, Marksman carbine)
 * New California Republic Rangers veterans equipped with NCR Ranger combat armor, combat knives and a high powered firearm (hunting shotgun, hunting revolver, Ranger Sequoia, brush gun, trail carbine, assault carbine, anti-materiel rifle)

Caesar's Legion

 * Legate Lanius, supreme commander of the Legion (Dam)

Troops

 * Caesar's Legionaries equipped with basic, intermediate, or veteran armors, throwing spears, pistols (9 and 10mm pistols and .357 and .44 Magnum revolvers), rifles (cowboy repeaters, hunting rifles, and Marksman carbines) and assorted melee weapons.
 * Legion Decanii equipped with basic and intermediate armors, throwing spears, caravan shotguns, 9 and 10mm submachine guns and machetes
 * Centurions equipped with elite metal armor, machete gladii, chainsaws, thermic lances, hunting shotguns, super sledges and Marksman carbines.

Independent

 * Mr. Robert House, sole proprietor of the New Vegas Strip
 * Courier, aid to Mr. House and commander of independent forces.

Troops

 * Securitron army equipped with X-25 Gatling laser and M-235 missile launchers.

Hoover Dam
The Courier's role in the battle depends greatly on which faction they have sided with.

If the Courier sided with Mr. House or Yes Man, the battle plays out in a similar fashion, both involving the activation of the Securitron army. From there, the Courier is forced to fight their way across the dam and into the Legion Camp.

The New California Republic quest has the Courier perform the same basic task: fighting through enemy forces to get to the Legion Camp on the other side of the dam.

While traversing the dam, any aid the Courier had enlisted will be acted upon by the corresponding faction. Once the Courier reaches the other side of the dam and enters the Legate's Camp, they will face off against Legate Lanius. The resulting confrontation will either have the Courier fight and kill the Legate, or solve the confrontation diplomatically. After dealing with the Legate, the Courier returns to the main gate, at which point General Lee Oliver and his men destroy it. If siding with the NCR, Oliver will congratulate the Courier; however, if siding with Yes Man or Mr. House, the Courier will be forced to confront General Oliver, either having to fight and kill Oliver and his men or solve the issue through diplomacy.

If the Courier sided with the polar opposite, Caesar's Legion, the battle plays out in a similar fashion to the battle involving the Courier siding with the NCR, only it will playout in reverse; the Courier starts at the Legate's Camp, and then fights their way across the dam to reach the NCR's position, confronting General Oliver. Once again the Courier is forced to choose between killing the General or convincing him to leave without fighting through diplomacy.

Elsewhere
The details of the battle at Hoover Dam are unclear, however the fighting was not just limited to that relatively small location; violence engulfed the entire Mojave Wasteland as Legion forces and its allies attacked NCR targets and locations across the region, with varying levels of success:
 * The NCR Embassy on the New Vegas Strip was bombed, and if they had not been stopped by the Courier already, the Omertas attempted a coup d'état but were stopped by the Chairmen as well as the Securitrons.
 * Rioting broke out in Freeside, although its severity is unclear; if the Courier forged an alliance between the Kings and the NCR, the riots were far more tame.
 * The Fiends attacked Camp McCarran, but if the Courier killed their leaders beforehand, they are easily repulsed.
 * Camp Forlorn Hope was attacked by the Legion, but if 1st Recon were present and the Courier managed to solve the camp's many problems, the NCR soldiers were able to fend off the attack.
 * The Frumentarii made an attempt to bomb the monorail outside McCarran, whether it was successful or not depends on whether the Courier uncovered their plot.
 * Camp Golf was attacked, but the Legion were, due to a heroic effort from the Misfits (if they were trained by the Courier), easily defeated, otherwise Chief Hanlon and the other rangers stationed there are able to fend off the Legion assault on their own.
 * Novac was attacked by the Legion and many of its citizens were said to have died in its defense, but if the Bright Brotherhood was aided in starting on their pilgrimage, they returned in time to help evacuate the citizens.

Appearances
The Second Battle of Hoover Dam is the finale of Fallout: New Vegas.