Wild Card: Change in Management

Wild Card: Change in Management is a main quest in Fallout: New Vegas.

Synopsis
If the Courier is going to establish an Independent Vegas with the help of Yes Man, some people will need to be fired, namely CEO Mr. House.

Quick walkthrough
This series of quests leads to one of many Fallout: New Vegas endings. Once the Courier discovers Yes Man, he will explain Benny's plan to kill Mr. House and take over New Vegas. The player character will then be able to choose either to continue with Benny's plans or take on this quest, killing Benny. The Courier will have to head towards the Lucky 38 penthouse, locate the chamber in which Mr. House actually resides, and either choose to disable him or kill him. If one chooses to kill Mr. House, meet Yes Man at The Tops casino and accompany him to Lucky 38.

Detailed walkthrough
After entering the Lucky 38 penthouse, find a terminal on the wall near Mr. House. This terminal will allow one to unlock a hidden door (named the antechamber) leading to Mr. House's chamber. Unlocking the terminal requires either:
 * 75 Science
 * A Lucky 38 VIP keycard from the H&H Tools factory (top floor) or from the top of Chief Hanlon's desk in his office (inside the main building at Camp Golf).
 * The Platinum Chip.

After activating the door, an alarm will sound and the securitrons will become hostile. Behind the hidden door are two more terminals. The terminal on the right in the back allows a "Security Override" to be performed which will stop any remaining securitrons from attacking on sight. The second terminal, on the left near the elevator, is used to unlock the elevator. Activate this to head on to the control room.

Once in the control room, there is one final terminal. Activate it to release Mr. House's isolation chamber and expose him to the outside world. The player character can then talk to him, and he will tell them how your "Vanity Project is doomed to fail." His fate can be decided by going back to the terminal and choosing to either kill him (also possible via the "sterilize chamber" option) or leave him helpless, both of which result in loss of Karma. Note that once the isolation chamber has been opened, regardless of the fate you decide for Mr. House, he will die within a year from exposure to outside contaminants. Alternatively, after the player character has opened the chamber, they can attack him.

To pass the initial terminal, one can choose to either pass a Hard difficulty hack or execute an executive override and obtain the password to the terminal from either H&H Tools factory or the hotel in Camp Golf.

If the Courier decides to kill Mr. House, they will receive the note A Tragedy Has Befallen All Mankind, and the quest The House Has Gone Bust! will instantly be started and failed.

Once the Courier has killed Mr. House, it is time to meet Yes Man. Return to Benny's suite at the Tops - he's in the room beyond his bed. Talk to him and he'll agree to meet the player character at the Lucky 38.

Sometimes, Yes Man disappears after you kill Benny, if the Courier leaves Benny's apartment and returns later. He can be found standing outside of The Tops casino. He can be told to meet up at the Lucky 38 without incurring any faction penalties. Once the player character meets him in the Penthouse of the Lucky 38, where House's avatar formerly spoke to Courier the first time, the installation of Yes Man is triggered. This triggers two quests: Beware the Wrath of Caesar! and Don't Tread on the Bear!. This puts the player character on notice that working with Yes Man further will cause the player character to be unable to work with those factions.

After installing him on the Lucky 38 mainframe, he will make the demonstration about the Securitron upgrades at the Lucky 38 basement.

One can let Yes Man wait for them at the Lucky 38 until the player character finishes most of the other quests with the NCR and Caesar's Legion and are ready to proceed.

Bugs

 * Sometimes, when Mr. House is killed and you return to Yes Man to take over, Yes Man will go towards the Lucky 38 and disappear. This will cause the game to glitch when returning to the Lucky 38, making a fade out and fade in effect, when a cutscene with Yes Man should normally play. The player will then be unable to move, but can still look around on the spot and the Pipboy will be unaccessible. This can sometimes be fixed by completing Wild Card: Side Bets first, and then returning to Yes Man, or entering the Cocktail Lounge via the Lucky 38's main elevator.
 * If, after informing Mr. House you're keeping the chip no matter what, you leave the Lucky 38 without killing or disabling him (and even if you killed Victor in the ensuing fight) an unarmed Securitron with Victor's face will chase you around the strip, punching you. He can't follow you into Strip establishments, but people all around you panic as if he were there.
 * Sometimes you will try to access the Penthouse terminal to enter the inner chamber, but it will not trigger. Also sometimes the terminal doesn't open immediately (just beeps) but if you turn away the terminal screen appears wherever you are in the room. It may just require waiting several minutes after using the open command to begin using the terminal.
 * You discover Yes Man after you have killed both Benny and Mr House, as well as destroyed the Securitron bunker, and you tell Yes Man about your actions (it may not matter if you say anything). A flashing waypoint will lead you to Yes Man once you leave dialogue. You cannot enter a dialogue, but Yes Man tells you he can't wait to get into the mainframe. Completing the quest Wild Card: Side Bets may resolve this bug.
 * After observing the Secturitron upgrades and being returned to Yes Man, speaking to him again to receive the note regarding the Secturitron bunker at the Fort will cause the Wait and 3rd/1st person view buttons to become unresponsive. This makes waiting and toggling 3rd/1st person view permanently unavailable. It is possible to completely avoid this conversation, as it is not a requirement for carrying out Wild Card: You and What Army?
 * Sometimes, after you have killed Mr. House there will be no marker leading you back to Yes Man to ask him to meet you at the Lucky 38 Casino, however this does not affect progress as the lack of a marker does not affect progression.