Laser

Cyclops and Marvel Girl fighting in the Danger Room, Earth-92131, with Cyclops using a laser beam from his eyes. (TV: Proteus (episode 1) ^[+]Loading...{"timestamp":"5:37","ep":"1","1":"Proteus (TV story)"})

A laser was, in a description posited by Leela and approved by the Fourth Doctor, a very powerful light. (TV: Horror of Fang Rock) The word "laser" was an acronym for Light Amplification by Stimulated Emission of Radiation. (PROSE: Time Lord Technology ^[+]Loading...{"page":"57","1":"Time Lord Technology (feature)"}) Many lasers were harmless and used in some games, but others were used as deadly weapons. During their campaign to recruit warriors, the Uvodni utilised harmless laser weapons in their interactive laser-tag game Combat 3000. However, on board their ship, the Kudlak warriors carried deadly blaster rifles that fired a yellow laser burst. (TV: Warriors of Kudlak)

Some weapons, such as Sontaran lasers, were called "lasers" despite travelling slower than light. (TV: The Sontaran Stratagem)

Uses of lasers

Lasers were frequently used in weaponry such as laser rays, beams, or guns. (TV: The Power of the Daleks, etc.)

Lasers could also be used for a defensive purpose to guard vaults or other secure locations. If the laser beams were interrupted by a person, they would trigger an alarm. This method of defense could be defeated by changing the refractive index of the air, or by using a prismatic beam. (TV: City of Death)

Outside of weaponry or defense, lasers were also employed for peaceful purposes:

• In surgery, lasers were found in laser scalpels (TV: Mindwarp) and laser saws. (TV: Children of Earth: Day One)
• They were also used for scientific purposes in material analysis, although the Third Doctor derided them as "primitive". (TV: Spearhead from Space)
• Holograms were created using lasers to project light. (TV: The Talons of Weng-Chiang)
• Laser scopes were used by the Daleks on Skaro as surveillance devices. (TV: The Daleks)
• Animals and their habitats could be converted into magnetic signals and held within laser crystals using a Continuous Event Transmuter. (TV: Nightmare of Eden)
• A laser cutter could be used to cut circuits or other objects. (TV: Earthshock) Similarly, lasers could be used to bore into the crust of a planet. (TV: The Runaway Bride)
• The Tenth Doctor claimed to have owned a laser spanner, (TV: Smith and Jones) which had a torch. (PROSE: The Mystery of the Haunted Cottage)
• Laser signals could be used to transmit information and to synchronise communications. (TV: Resolution)

Examples of laser weapon use

During his 43 AD scheme, the War Chief put his hypnotised prisoners to work constructing laser weapons of his own design for themselves, including unusually compact Laser Pistols. (GAME: The Legions of Death ^[+]Loading...["The Legions of Death (game)"])

The Third Doctor used a laser stick. (COMIC: Backtime) The Eleventh Doctor's sonic screwdriver was able to fire a defensive laser, capable of stunning a Cybermat. (TV: Closing Time) When the Twelfth Doctor left one of these screwdrivers in the possession of a young Davros, the Kaled increased the output of the laser into a true weapon, one capable of burning flesh. (PROSE: The Last of the Dals)

The Cybermen were armed with a wrist-mounted laser blaster that fired a red blast. (TV: The Pandorica Opens)

The Daleks used gunsticks which fired laser rays which could be modified into hand-held Tommy rifles. (TV: Evolution of the Daleks)

Graske on the planet Griffoth were armed with tiny laser pistols which fired purple blasts to combat intruders. (GAME: Attack of the Graske ^[+]Loading...["Attack of the Graske (video game)"])

The parallel Torchwood developed laser weapons, which destroyed Cybermen and could blast through a Dalek's shield. (TV: Doomsday) These weapons were later upgraded, to the point that they could destroy Daleks in one shot. (TV: The Stolen Earth)

Jack Harkness had a compact laser deluxe and once used components from a pair of androids to build a high-powered energy weapon out of a defabricator. (TV: Bad Wolf) During the subsequent Battle of the Game Station, Jack set up a laser defence grid to hold off the Daleks only for the invaders to override it. (TV: The Parting of the Ways)

The Sontarans utilised laser rifles during their invasion attempt. In addition, Sontaran batons fired a laser that could cripple their victims. (TV: The Poison Sky)

The Judoon carried hand-held blaster pistols which fired a red disintegrator beam. (TV: Smith and Jones)

The Toclafane had laser blasters built in to their casings. (TV: The Sound of Drums)

Chantho used a laser pistol to shoot the Master. (TV: Utopia)

Eva Saint Julienne used a laser pistol to shoot the Jagrafess. (TV: The Long Game)

Novice Hame carried a laser gun for protection when searching for the Tenth Doctor. (TV: Gridlock)

The Master occasionally used a hand-held laser gun. (TV: The Claws of Axos, Colony in Space) The Saxon Master used a laser screwdriver as his primary offensive weapon. (TV: The Sound of Drums, Last of the Time Lords, The Doctor Falls)

The Slitheen-Blathereen family used bracelets which fired orange lasers. (TV: The Gift)

The Merons carried a trident-shaped weapon which shot three green beams. (TV: Liberation)

The Korven had laser weapons on their palms. (TV: The Korven)

Ahab made use of a laser lasso. (TV: The Bounty Hunter)

CCPCs were armed with a palm-mounted laser blaster that fired a red beam. (TV: Aeolian)

The Chameleons threatened the Second Doctor's and Samantha Briggs's lives with a laser beam. (TV: The Faceless Ones)

The zuqaqip were armed with lasers capable of melting rock. (PROSE: Timewyrm: Genesys)

After they went mad and started killing people, the robots who briefly replaced the teachers at Lucy Wilson and Hobo Kostinen's school were equipped with deadly lasers. (PROSE: The Robot Invasion)

As an ability

Some humans who the Rani injected with a "super gene" were able to shoot laser beams from their eyes. (GAME: The 'X' Factor ^[+]Loading...["The 'X' Factor (game)"])

Other realities

Earth-92131

In Earth-92131, some mutants were able to make use of laser beams, such as Cyclops, who could fire beams from his eyes. (TV: Proteus (episode 1) ^[+]Loading...{"ep":"1","1":"Proteus (TV story)"})