Hologram

A hologram is a volumetric, three dimensional image displayed by an advanced projector that utilizes holographic technology.

Background
 During the Sino-American War, research efforts were undertaken to weaponize holography, most notably at the Big MT research facility. Basing on RobCo Stealth Boy technology reverse engineered from captured Chinese stealth suits, the researchers attempted to create a design capable of matching the Chinese technological edge. Despite promising initial results, holograms required excessive amounts of electricity to power, greatly limiting their potential. Actual, mobile holograms never reached any popularity in the United States.

In fact, the entire program teetered on the brink of cancellation. However, the insistence of Frederick Sinclair, his money, and support from National Electric kept it going. The researchers at Big MT's Z-38 lightwave dynamics research facility developed the first working holograms, although their functionality was limited. They were only good as holographic greeters and walking cameras, unsuited for combat. Contrary to their expectations, National Electric not only managed to weaponize holograms with their proprietary Emergency Broadcast Emitter (EBE) technology, but also commercialize it. However, they only managed to deliver their technology to one client: Frederick Sinclair and the Sierra Madre Casino. The EBE allowed holograms to attack identified threats with lethal force, while remaining practically invulnerable to retaliation. Their only weak point were emitters, which could be destroyed despite their space age alloy housing or disabled if someone tampered with circuits. However, if the emitters were safe, custom energy recycling emitters could keep them going indefinitely. 

Characteristics
 Sierra Madre holograms, as projections, rather than actual physical entities, are invulnerable to damage. They are divided into two distinct groups: Service and security holograms, all modeled after actual Sierra Madre personnel. The former are simple utility projections, providing the automated systems of the Villa and the Casino (such as vending points or casino games) with an user-friendly interface. These are non-hostile and are not equipped with an EBE device. In case of an emergency, the service holograms are disabled and replaced with security variants.

The security holograms are a completely different affair. As invulnerable as the service holograms, they are designed for enforcing order and security at the Casino and the Villa, designed to supplant traditional security guards. Their security protocols allow them to perceive their environment in a roughly 90 degree cone in front of them, with the planned 360 degree perception arc upgrade never materializing due to the war. National Electric recommended the purchase of two emitters to allow for paired deployment in a kind of robotic buddy system. These blindspots represent the only advantage an unauthorized invader has over the holograms, as staying out of the hologram's field of view will prevent retaliation.

If detected, the holograms will first display a warning color (changing their silhouette to yellow), and then transfer to engagement mode (signified by a red colored silhouette), attempting to subdue the offender with their discharge beams. The holograms were programmed to engage intruders and people committing criminal activities. All holograms in the Sierra Madre have their EBE systems configured to kill, rather than subdue. If the target evades the hologram, it will resume its normal routine after some time. This is made easier by the fact that the emitters have a limited range and will only pursue the target as far as their perimeter allows.

The only way to permanently disable a hologram is to destroy its emitter. Although housed in space age alloys, they can be destroyed with blunt force or disabled by tampering with their circuits. The latter generally meant having to contact National Electric for repairs, as user maintenance was strongly discouraged. 

Appearances
Holograms appear in Fallout 3 add-ons Point Lookout and Mothership Zeta, in Fallout: New Vegas add-ons Dead Money and Old World Blues, and in Fallout: Brotherhood of Steel.

They were also to appear in Fallout 2 in the cut location Environmental Protection Agency, and in Van Buren, the canceled Fallout 3 by Black Isle Studios.