Force field

A force field (sometimes known as a "force shield") was an item of defensive technology that could be used to protect an object, person, or space. It was mostly employed to deflect outside forces, but could also be used to keep things in, such as oxygen or heat. Force fields had limitations. The larger the space one needed to protect and the more energy the force field was required to deflect, the higher the energy requirements of the force field. (TV: The Armageddon Factor) Article 57 of the Shadow Proclamation stated that enclosing a Level Five planet in a force field was illegal. Despite this, in the early 21st century the Atraxi enclosed the Earth in a force field in preparation for its destruction in order to capture Prisoner Zero. (TV: The Eleventh Hour) The term "force field" was used to cover a wide variety of defensive technologies based on an energy barrier. In the mid 1970s on Earth, Cessair of Diplos was capable of creating a static electric force field, (TV: The Stones of Blood) whilst it would take until the mid-21st century for force field technology to be common place on human-based space craft. (TV: The Wheel in Space)

Force fields could be used in a passive form of aggression, such as preventing a ship from leaving a planet. (COMIC: Mission for Duh)

Most space faring species had some form of force fields for protection, such as the Rills (TV: Galaxy 4) and the Daleks. (TV: Victory of the Daleks)

Craft-based forced fields
In the 15th century the Exxilons used force fields on their ships to protect the fuel pods (fuelled by plutonium) against radiation exposure. (PROSE: The Left-Handed Hummingbird)

The Doctor's TARDIS had a force field generator. In the 1970s the Second Doctor's recorder was protected from being converted into antimatter, because it was inside of the force field generator. The Doctor gave the recorder to Omega, causing his antimatter world to be destroyed, along with the TARDIS' force field generator. The Third Doctor decided to remain on Earth until the force field generator was rebuilt, even though the Time Lords had lifted his exile on Earth. (TV: The Three Doctors) By the Doctor's ninth incarnation, he no longer had a force field generator, and instead used a tribophysical waveform macrokinetic extrapolator. (TV: The Parting of the Ways) During the Eleventh Doctor's life, the TARDIS again had a force field that it used to protect Clara Oswald in the time vortex when she was locked out of the TARDIS but refused to let go of the doors. (TV: The Time of the Doctor)

In the early 21st century, space craft such as the Titanic were equipped with force shields to protect them from space-based hazards such as asteroids. Warnings on the bridge would be sounded should they be lowered in the face of such dangers. (TV: Voyage of the Damned) Also in the early 21st century, the airborne military carrier the Valiant was equipped with force shields. They were defeated by Dalek weaponry. (TV: The Stolen Earth)

In the latter part of the 21st century the Space Station W3 was armed with a force field in addition to an X-ray laser. (TV: The Wheel in Space)

In the 42nd century many human ships and bases had force fields to protect them from the effects of space. (TV: 42, The Impossible Planet)

By the year 200,100, the Game Station was protected by a force field which prevented the invading Dalek Fleet from blasting it out of the sky, but it didn't stop the Daleks from boarding the station. (TV: The Parting of the Ways)

By 5,000,000,000, Platform One was protected by a force field so that no damage would come to the station when the Earth was engulfed by the sun and destroyed. (TV: The End of the World)

The War Lords and the Time Lords were both capable of creating forcefields within their craft or facilities that were similar in appearance. (TV: The War Games)

Device-based force fields
The Sontaran Styre imprisoned Sarah Jane Smith in a force field on the Earth of the 30th century. (TV: The Sontaran Experiment)

In 2006 Margaret Blaine stole a tribophysical waveform macrokinetic extrapolator that could generate a shield powerful enough to protect her from a nuclear meltdown. (TV: Boom Town)

In 2007 Torchwood Three owned a portable prison cell that could generate a funnel of energy around its captive. (TV: Day One)

Last Great Time War-era Dalek prison cells used force field technology to hold their captives. (TV: Journey's End)

Mr Smith was able to project a force field of limited range and power inside of Sarah Jane's attic. It was also capable of draining the power of any devices inside it. (TV: Enemy of the Bane, Goodbye, Sarah Jane Smith)

In the year 4000, when Bret Vyon was within the Doctor's TARDIS, the First Doctor created a 'magnetic chair', which had a force field strong enough to restrain "a herd of elephants". (TV: The Daleks' Master Plan)

On Wengrol, Yend scientists used force fields to restrain specimens. (PROSE: The Sons of the Crab)

Individual-specific force fields
Encountering the Celestial Toymaker in 1980s Blackpool, the Sixth Doctor trapped him within a self-sustaining force field maintained by the Toymaker's own mental abilities. (PROSE: The Nightmare Fair/AUDIO: The Nightmare Fair)

In 2002, the Seventh Doctor created a force field generator which could tune into the Fearmonger's wavelength and used it to destroy the creature without harming its host. (AUDIO: The Fearmonger)

In 21st century Cardiff, members of Cell 114 were protected by a force field that was one nanometre thick, mostly around the location of the implant. (TV: Sleeper)

In 2050 K9 Mark 2 encountered the Bodach, a species that created a force field around themselves. (TV: Dream-Eaters)

Species-specific force fields
Daleks from the Last Great Time War era were surrounded by force fields that prevented bullets and energy weapons from making contact with their casings. (TV: Dalek, The Parting of the Ways, Doomsday, Daleks in Manhattan, The Big Bang)

The Korven were capable of creating immobilising force fields. (TV: The Korven)

Location-based force fields
On Gallifrey in the Death Zone, the Dark Tower was protected by a force field that prevented entry to it via transmat and by TARDIS. It could be disabled from within the Tower however. (TV: The Five Doctors)

The Dalek Asylum was protected by a force field, covering the entire planet. Despite wishing to preserve the Daleks contained there, when the security was compromised by a crashed star-liner, the Parliament of the Daleks sent the Eleventh Doctor and his companions to lower the asylum's defences so they could destroy the asylum. Although the force field prevented the Daleks from destroying it, they managed to breach the force field via a gravity tunnel which allowed the Doctor and his companions to be sent there. The force field was eventually deactivated by Oswin Oswald, a human who was converted into a Dalek, allowing the Parliament to destroy the asylum and the Daleks imprisoned there. (TV: Asylum of the Daleks)

The Papal Mainframe put a force field around Trenzalore to prevent the Time Lords from returning to the universe should the First Question be answered. The force field also kept numerous species such as the Daleks, the Cybermen, the Sontarans, the Terileptils, the Slitheen, the Judoon and the Silurians out as they were prepared to attack the Time Lords and begin another Time War. As many of the species tried to pass through the force field, the Daleks called for reinforcements and attacked the Mainframe, learning how to break the force field by torturing and killing Tasha Lem "several times". The Siege of Trenzalore then became a war as the species orbiting the planet descended and fought against the Doctor and the Church's Silent priests. All combatants except the Daleks died or retreated in the fighting. (TV: The Time of the Doctor)

Other uses for force fields
Force fields could be used to form air corridors, allowing the passage from one ship to another without the extension of any form of docking tube. These force field extensions could be filled with air to allow normal passage. (TV: The Horns of Nimon)

Similarly, in 2008 when the Judoon used an H2O scoop on the Royal Hope Hospital, transporting it to the Moon, they surrounded it with an airtight force shield. (TV: Smith and Jones)

By the 30th century humans could achieve this form of technology. On Earth's moon they were able to project "force bubbles" onto the moon's surface, allowing for work to be conducted within an atmosphere. (PROSE: The Dust of Ages)

Other forms of energy field
Gallifrey was protected by a transduction barrier. This was similar to a force field. (TV: The Invasion of Time)