Type-27 hologram

The Type-27 Responsive Holographic Form Emulator, often shortened as "Hologram" or "T-27 Decoy package", is a piece of Covenant decoy technology. It was reverse-engineered by the UNSC, and is utilized by SPARTANs.

Overview
The only known Covenant species that uses the emulator are the Skirmishers, namely only the Skirmisher Champions and Commandos. Sometime before or during 2552, the emulator was reverse engineered from Covenant technology and was later integrated into the MJOLNIR Powered Assault Armor. The emulator creates an holographic copy of the user and can be commanded to move to locations chosen by the user. It is often used to deceive enemies.

To allies, the holographic copy would appear as a white dot on their motion tracker. The ability functions by pointing the targeting reticule at a destination and deploying it like other armor abilities. When activated, the hologram will run in a straight line to the destination and stop once it reaches its designated location. The hologram will flicker away if it is either damaged enough or if it reaches its lifespan limit (10 seconds). However, a new hologram can be produced after just 7 seconds, which would immediately dissipate the old one.

Disadvantage
The decoy can be identified by the thermal enhancement on the SRS99AM Sniper rifle's Oracle N-variant scope. On the scope, decoys appear as flickering white solids.

Halo: Reach

 * The hologram is useful in Campaign, since most enemies will fall for it. It is an effective way to test the number of enemies ahead of the player's position.
 * In multiplayer, one can evade a Energy Sword lunge by deploying a hologram at the last second. In Infection, this gives one a chance to attack the infected.

Halo 4
In Halo 4, projecting a hologram onto a corpse will cause the hologram to crouch up and down, humping it. The effect is not only humorous, it also increases the plausibility of the decoy.

List of appearances

 * Halo: Reach
 * Halo 4