All Or Nothing

All Or Nothing

This is it; the final battle.  You'll need to help Mr. House to gain full control of New Vegas (and the Mojave) again.

QUEST REWARD: 4000 EXP. 

Depending on which sidequests you did earlier, the following things can happen:

• If you made a deal between the NCR and the Great Khans, they'll fight along your side.  Otherwise, they might just turn up as a hostile group, but they are greatly outnumbered in any case.
• If you helped the Boomers, you'll soon enough spot Loyal's airplane which drops bombs on the Legion's troops.
• If you're hostile with the NCR, you'll have to fight them too.  Otherwise, they'll help you with your assault.

Head for the Hoover Dam Tower to the northeast, battling any hostiles along the way.  Inside, ride the elevator.  Search for the control room to the northeast, guarded by heavily armed NCR troops you'll need to dispatch before or after entering (or if you have 75 Speech, convince them to head elsewhere), and  access the large terminal here, using the Override Chip.  Head to the southeast area of the complex, dealing with NCR and Caesar's troops as you make your way to the switch you manually need to flip.  Open the door, check the right of the balcony and flip it.  Head to the north/northeast area to exit the tower.

Back outside, proceed over the dam and let the Securitrons handle the Legion Centurions as you eventually traverse southeast, uphill, towards the Legate Camp.  Inside, dispatch several Praetorian Guards and head up the steps on the far end of the camp.  Here you'll meet who you could call the final boss of the game in this scenario: Legate Lanius.  You have a whole lot of options in the dialogue, but ultimately you'll need 100 Speech or Barter to successfully make him retreat.

LEGATE LANIUS

Alternatively, and ultimately if you don't have a very high Speech and/or Barter skill, you'll have to fight Legate Lanius.  He's a tough, speedy behemoth with a huge amount of health and plenty of supporting Legion troops.

• Attempt to keep your distance and target Legate's legs to slow him down if you can manage to cripple one of his legs.
• Armor piercing ammunition will help tremendously in this fight as it'll at least help you damage Legate more than you normally would.
• Use Med-X, Psycho, and keep your health high with healing items and stimpaks at all times.
• Dispatch several Legion troops whenever you feel there are too many around you, and keep moving around to avoid getting cornered.

After finally defeating Legate, head back to the gate and general Lee Oliver of the NCR shows up.  You have several options now:

• Kill the general and his troops (by ordering the Securitrons to do so).
• Attempt a more friendly approach by saying you were hoping both sides could be pleasant about this.  The next speech challenge(s) require 100 Speech, but you can get him to leave by succeeding.

Mr. House then moves towards you as a Securitron and tells you that you've been a fabulous right hand, arguably the best he's ever had.  The game now concludes.

Taking the Hoover Dam for Victory!