All or Nothing

All or Nothing is the final main quest in Fallout: New Vegas, if the player chooses to side with Mr. House, It is also an achievement/trophy.

Synopsis
So much work and so many calculations have been brought together in this moment where Mr. House proves to the Mojave that the New Vegas Strip is his, and his alone.

Walkthrough

 * 1) Get inside the dam and install the override chip with the help of some Securitrons.
 * 2) Turn on the power to activate the Securitron army.
 * 3) Confront Legate Lanius. He can either be killed using conventional means, or he can be convinced to surrender with a Speech or Barter check of 100.
 * 4) Confront General Oliver and his entourage of six NCR Ranger Veterans. They can also be killed, or Oliver can be convinced to surrender with a Speech, Science or Barter of 100.
 * 5) Talk to Mr. House.

Bugs

 * If you kill Legate without talking to him, you will not be able to continue the quest and in certain occasions the Legate's model will start making awkward movements. This may be solved by either talking to the Legate and going through the normal speech options (if he still registers as alive) or by simply killing some Legion soldiers until the quest continues.