Hologram



A hologram is a projected three-dimensional representation of a person or object. It is a highly advanced, experimental technology that was never widely used before the Great War.

Background
 It's believed Holograms stemmed from Stealth Boy technology rising from scientific drive to match the chinese stealth armor, but the hologram technology never achieved the same level of prominence, notably due to the excessive energy constraints.

They were used in various government facilities, but the technology was never perfected except by a company known only as "N.E.", who sold the technology on an exclusive contract to Frederick Sinclair for use in the Sierra Madre casino. Because of the exclusive contract with Sinclair, scarcity and cost of energy, the hologram technology never became popular in the pre-War era, virtually unknown to the rest of the population and remained a rare technology.

They were to be used as greeters, vendors and as security, but their 'Emergency Broadcaster Emitter' systems meant that on the night of the Great War, the casino was locked down and the guests of the Sierra Madre Gala Event were massacred by them. The holograms have stood as the casino's guardians ever since. Elijah sought their technology because of their immense power - one, deployed in the right place, would become a one-man army, impossible to be destroyed until its emitter is found. 

Outside of the Sierra Madre, Professor Calvert used hologram technology to communicate with the tribals in the Fallout 3 add on Point Lookout, and the aliens aboard Mothership Zeta seem to have perfected the technology but do not use it as a weapon.

Vault-Tec also seemed to have an interest in this technology just before the Great War, as a holographic prototype system, allowing a person to use a holographic point for appearing on a another holographic point, giving a holographic appearance to talk only, is found in the Vault Prototype and the Secret Vault.

Characteristics
Service protocol holograms perform a specific function - greeters, simple vendors, or in the case of the Sierra Madre casino itself, even monitoring gambling tables. These service holograms follow simple routines, and are incapable of performing any security function. Holograms cannot move beyond range of their emitters and are best when used for a simple, localized function.

Security protocol holograms do just as the name implies: provide security. They perform this function better than most conventional security guards. Not only do security holograms look like Sierra Madre personnel, they will respond to threats or unauthorized personnel just as conventional security guards would.

Security holograms use field of view sensors to perceive their environment and to aid in pathing. The memory cells in hologram emitters can only perceive their environment in a cone in front of them. They can, however, change facing as needed and scan their environment for unauthorized activity. Security holograms are often found in pairs to cover a full view of the environment, as trespassers could conceivably use hologram blindspots to gain access to unauthorized areas.

If security holograms detect unauthorized guests or detect criminal action, they will display a warning "caution" color to the target. If the behavior persists, they will enter engagement mode, turn red, and attempt to subdue targets with their discharge beams.

Often, an intruder's natural response is to attack a security hologram, either with fists or with a weapon. Unfortunately, all such assaults are useless against security holograms. They cannot be wounded, damaged, or harmed unless their emitter is destroyed. Attackers spending the time to look for emitters will usually be rendered unconscious by a hologram's discharge beams before they can disable them.

As with service holograms, security holograms cannot leave emitter range. They will pursue a target to the emitter's perimeter, however. Hologram emitters are sturdy, yet can still be damaged or broken if enough force is applied. In addition, while they are protected inside sturdy space age alloys, their circuits are vulnerable to being tampered with.

Appearances
Holograms appear in Fallout: Brotherhood of Steel, Point Lookout, Mothership Zeta and Dead Money.

They were also part of the cut Environmental Protection Agency in Fallout 2, and Diana Stone would have used a hologram to communicate with Twin Mothers in Black Isle's canceled Fallout 3.

Bugs

 * When seeing a Hologram and then quickloading the game, the Hologram's color can go dark. They still flicker, but they won't be blue anymore, and it may be hard to see them. Only way to fix this is to open console click on the hologram till the hologram NPC's ref. ID shows up and type "resurrect".
 * Rarely, they can be killed with gas bomb, frag grenade or C4 and give 10-20 xp.