Yes Man

Yes Man is an AI program that serves as Benny's assistant and right-hand man in 2281, and is an integral part of Benny's scheme to take control of New Vegas. Yes Man appears to be a modified Securitron. More specifically, his personality program has been put into a PDQ-88b Securitron; although he may later assist the Courier in the "independent" New Vegas options for the game's ending as the Lucky 38's mainframe.

Background
Yes Man was originally a generic Securitron robot programmed to work for Mr. House like all the other Securitrons found on The Strip. He was recovered by Benny and several of the Chairmen after being damaged by a pulse grenade. Following this incident, Followers of the Apocalypse member Emily Ortal examined the Securitron in order to learn Mr. House's secrets in exchange for reprogramming him for Benny's personal use.

The reprogramming was extensive, and resulted in Yes Man being designed to do exactly as he is told; thus, Yes Man is not just the program's name, it's also its job description. Yes Man is completely incapable of declining any order or withholding any information he is asked for, no matter who he is interacting with. Benny's plan was to dispose of Mr. House and install Yes Man's A.I. onto the Lucky 38 mainframe, putting Yes Man (and by extension, Benny) in control of all the Securitrons on the Strip. The next step was to take the platinum chip to the Fort, take control of the great weapon he suspected Mr. House of having hidden away (as he did not know exactly what was stored there), and use this "weapon" to assume control of New Vegas and Hoover Dam.

Location
Yes Man is initially located in Benny's suite in The Tops casino. To gain access to Yes Man, the Courier must either kill Benny in the casino, sleep with him (needs Black Widow perk), present Swank with evidence of Benny's treachery, or confront him and force him to flee to the Fort.

To find Yes Man, enter The Tops casino and proceed straight ahead past the casino floor to the elevator bank (near the sign that says "Elevators out of Order"). Take the second elevator on the right to the 13th floor. Exit the elevator, turn right, and enter the third set of doors on the left side of the corridor (double doors with potted trees flanking them). Go into the room and through the hole in the wall in the back of the room.

After the player finishes Ring-a-Ding-Ding!, Yes Man will have moved to the front of The Tops casino in order to begin communication and further mission progress with the Courier.

Quests

 * Wild Card: Ace in the Hole: The Courier meets Yes Man for the first time. As there is no restriction on who Yes Man can help, the Courier can interrogate him to find all the details of Benny's plan, and even continue it themselves.
 * Wild Card: Change in Management: The Courier must obtain the platinum chip, assassinate Mr. House, and install Yes Man's A.I. in the Lucky 38 mainframe.
 * Wild Card: You and What Army?: The Courier must travel east of the Colorado River to The Fort and activate an army of Securitrons locked away in House's secret Securitron vault.
 * Wild Card: Side Bets: The Courier can meet with the various tribes of the Mojave and decide who will be spared in the upcoming battle for Hoover Dam.
 * Wild Card: Finishing Touches: The Courier must convince Julie Farkas to support an independent Vegas; (optional) protect President Kimball against an assassination attempt; and use an override on the El Dorado substation in order to power the Lucky 38 and allow it to broadcast the Securitron operating system upgrade.
 * No Gods, No Masters: The Courier must power up the secret Vault, allowing the Securitrons within to break out and crush the Legion, before convincing the NCR to leave the Dam to Vegas - by force, if necessary.

Effects of the player's actions
After the assault on Hoover Dam, Yes Man informs you that he has found pieces of code within Mr. House's mainframe that will "change his personality," and that he will seem to be offline for a little while until his personality change is complete. This personality change makes him more assertive, meaning that he will take orders only from the Courier in the future.

Appearances
Yes Man appears only in Fallout: New Vegas.

Behind the scenes
A "yes man" is someone who agrees to everything suggested by their superior, no matter what the task.