A Holographic Environment Simulator, or holodeck for short, was a form of holotechnology designed and used by the Alliance of Nations (most notably, the United Federation of Planets). They were installed aboard starships, space stations, and at Starfleet institutions for entertainment, training, and investigative purposes. A typical holodeck consisted of a room equipped with a hologrid containing omnidirectional holographic diodes, enabling holographic projections through the manipulation of photons contained within force fields.
The most obvious function of a holodeck is to provide entertainment and diversion for the crew.
A holodeck can be used to create training simulations and exercise environments not otherwise available or safe.
The holodeck can be used as a laboratory to aid in analysis, such as recreating the scene of a crime or accident to aid in forensic investigations. They can be used to visualize a 3D scene from alternate data sources for analysis or used as a brainstorming tool.
A holodeck combines elements of transporter technology with that of replicators, by generating actual matter, as well as projecting force fields to give the objects the illusion of substance. It can be controlled from an exterior control or the interior arch control. This arch can be summoned at any time to change the parameters of a running holoprogram. Matter and energy are interchangeable as such objects created on the holodeck can be either matter or energy.
Starships with a holodeck normally had a vast list of holoprograms in their computer. Several notable programs included:
- A woodland setting, resembling Earth, which featured a rock-jumping challenge, some of which were seemingly impossible to complete.
- A New Orleans jazz nightclub.
- The Versai Folk Club, which was women want dancing, especially the Orions and Twi'leks
- Sherlock Holmes mysteries, where the user assumed the role of Sherlock Holmes and/or Dr. Watson
- First Battle of Geonosis battle simulator
- Café des Artistes – "Enjoy a meal at a French cafe."
- Charnock's Comedy Cabaret – "Laugh in 1999-2100 N.E century comedy club."
- The Big Good-Bye – "The 1940s world of gumshoe detective Dixon Hill."
- Cliffs of Heaven – "From planet Elane IV, a safe experience.
- Equestrian Adventure – "Horse riding in an open country..."
- Calisthenics Program of Captain BJ Blazkowicz– a swamp-like setting where various enemies tested ones fighting skill.
- The bridge of many starships – the user could select any of the bridges of the various allied ships
- Tauris Underground – a simulation where soldiers could prepare for missions on the Desert planet of Tauris.
- A game of sabacc where Lando Calrissian won and own the Millennium Falcon.
- Tantive IV battle recreation
- Duel on Mustafar
- Janeway Lambda one
- Paxau Resort
- Insurrection Alpha
- Advanced Combat Simulator
- The Adventures of Flotter
- The Adventures of Captain Proton
- Fair Haven
- Photons Be Free
- Holographic family
- A beach setting allowing for swimming.
- A woodland environment allowing for a nature walk.
- An arctic wasteland.
- An 18th century style hedge-maze.