THE CHILDREN OF GALLIFREY
The Biology of Modern Gallifreyans

Gallifreyans are bipedal. Aside from two extra ribs (for a total of 26) a Gallifreyan's skeleton is almost identical to a humans. Their teeth are immune to normal forms of tooth decay, so they never needed to brush their teeth. However, when damaged, they can end up needing fillings inserted in their teeth. These fillings are supposed to regenerate when their body regenerates (though this process isn't perfect). By human standards, most Gallifreyans are 1.5 - 2 meters tall, with solemn, learned faces.

Gallifreyans have got multiple organs of virtually everything. They have 2 of most of the organs that humans have only one of, and 4 of the organs that humans have only two of. Some sources say the have only one liver, others say two (this could vary from House to House?) The also have several organs that have no real analogue with those found in humans. Indeed, despite looking like humans from Sol III, biologically speaking Gallifreyans have much more in common with Chelonians. Just about every one of their organs are much more efficient and effective then a human’s equivalent. Their internal body temperature is 15 (or 16) degrees Celsius (59 to 61 degrees Fahrenheit) however their skin temperature is only a little below the human norm. With a a fair amount of concentration, a Gallifreyan bring their body temperature down to 34 degrees Fahrenheit, though their attention span is greatly reduced. By speeding up their heart rate a Gallifreyan can raise his body temperature to levels high enough to steam dry their soaking wet clothes in 20 minutes. This heat is such that it can become uncomfortable for humans who have to touch a Gallifreyan for a long period of time.

Gallifreyans tend to find a room temp of 20 C to be uncomfortably hot. Despite this, adult Gallifreyans are capable of withstanding extreme temperatures at both ends of the scales. Due to their low body temperature, spending several minutes immersed in ice filled water feels briskly refreshing to a Gallifreyan. They can withstand 200 degrees C for up to 3 minutes and remain aware and physically active in the -270 C cold of outer space for 6 minutes (though they can be permanently blinded if their eyes aren't protected). Temperatures of several hundred degrees below 0 C will cause a Gallifreyan to lose control of their body and appear dead. But even in this state their mind is infact very active. They can't experience true thoughts or memories at these temperatures, but emotions and impressions from there senses can be perceived. Freezing a Time Lord for millions of years is likely to cause temporary amnesia. Gallifreyan's with only one heart suffer chills much more easily and probably find extremely low temperatures to be significantly more painful.

 Gallifreyan probably have tonsils and its not probably not unknown for them to have to be removed. Gallifreyans have more than one stomach and are not as vulnerable to malnutrition as Humans are. Gallifreyans eat breakfast in the morning, but some, if not all, believe that only one meal a day is perfectly normal. Despite this their metabolism is relatively close to a humans and they can eat the same foods. They don’t have to worry about eating too much fried food due to the biogenic molecules that clean the arteries. Some Gallifreyans can use their stomachs to interpret human memory RNA and producing the Gallifreyan equivalent. They and can easily go two days without water and a week without food is not a major strain. While they sometimes sit in thought for days without food or water, Gallifreyans tend to be cranky if they don’t eat regularly. There are limits, 40 days without food or water will make a Gallifreyan delirious. Gallifreyans normally have blue kidneys. They need to urinate every few days. Like the Shobogans of ancient times, Modern Gallifreyans possess the ability to detoxify many types of poisons and toxins. Gallifreyans metabolize alcohol very quickly so it is almost impossible for them to become drunk or suffer the effects of hallucinogens. Thus can easily drink 10 pints of beer without showing any ill effects. It takes roughly twice the normal amount of sedatives to knock them out. Some Gallifreyans can use special meditations to regulate their metabolism. This gives them a very fine control over the rate at which they metabolize alcohol, making inebriation or hallucinations possible. However Ginger pop has a severely deleterious effect on any Gallifreyan metabolism. This allows them to be easily effected by any alcohol they might have consumed. 

Arsenic is toxic to Gallifreyans and will inhibit their enzymes. If a large source of protein, salt, and other chemicals (found in ginger beer) are available a Gallifreyan who has been poisoned with arsenic can use a major shock or surprise to trigger Detox. This detoxification allows their stomach to stimulate inhibited enzymes to reverse and release all toxins a gas that can be exhaled. Detox can render psilocybin harmless by modifying its chemical structure. They can detox some types of poison gas using a chicken chocolate sandwhich. Aspirin is incredibly toxic to Gallifreyans. When exposed, an allergic reactions occurs when aspirin begins to interfere with hormone receptor intermediaries,stops platelet aggregation, and interferes with a Gallifreyan's genetic structure. All of this causes a massive pulmonary and cerebral embolism, severe enough to prevent regeneration. Even touching Aspirin can be dangerous. Detox can be used to negate aspirin poisoning if the Gallifreyan can consume some chocolate. The simple triglycerides in the chocolate combats the anti-platelets effect of the aspirin. While aspirin (and many other human medicines) is toxic to a Gallifreyan metabolism, they can handle 20th century broad spectrum antibiotics without significant trouble. Some Gallifreyans perform regular detoxes to improve their health. The Detox procedure doesn't work for all toxins.

Adrenalin significantly improves a Gallifreyan’s coordination. They have endorphins that are produced up when they are feeling exhilarated, but are not released while exercising (unlike in Humans). Kicking their two hearts and bi-vascular system into overdrive lets their whole body run at double a human's rates. This causes them pain and some dizziness – but gives them vast reservoirs of stamina. Gallifreyans don't have prostate glands. When trained they can control their adrenaline, blood-sugar levels, heart rate, respiration, and perspiration to the point where they can fool 23rd century medical diagnostics into thinking they are human. They can even switch off any of their organs at will.

They also have control over the speed and location of their hair growth. They can grow hair faster then humans or stop the growth completely. Despite this some Gallifreyans still shave their faces. The most common hair colors are black, brown, blond, and white.

While a Gallifreyan's skin often smells like honey, they can easily change their scent at will using olfactory misdirection. This allows them to hide from predators that hunt by scent. They have a wide range of smells they can pick from. Some Gallifreyans can make their skin appear pale and sickly at will. Racism based on skin color appears to be near inconceivable in modern Gallifreyan culture. Their skin has extra subdural and subcutaneous layers that will eject foreign objects such as subcutaneous implants. In order to keep an implant inside a Gallifreyan it must be attached to the cartilage. All of this makes their skin very resistant to radiation, physical damage, poison ivy, sunburns, and tanning. Gallifreyans can resist radiation that will kill a human in 4 minutes for 2-12 minutes before they start to take noticeable damage, and they are completely immune to some types of radiation. They can easily absorb 50 times the output of a 21st century medical X-ray machine (approximately 50 rems of Roentgen (aka X-Ray) radiation) and them expel it into any object they they can touch. A radiation level of Q15241 is not dangerous to a Time Lord. And a level of Q34911 is only safe for a short period. While black sun/star radiation drives most sapient beings murderously insane it has no affect on Gallifreyans.  A major exposure to radiation (approximately 2,000 rems for 1 hour) will take 23 days in a healing trance to expel. Any higher dose will require a regeneration. Incarnations which appear to be physically younger are much more resistant to radiation then older bodies. However 500,000 rads will kill even a Time Lord within a few hours.

Like the Shobogans of ancient times, modern Gallifreyans can erect non-porous barriers around their noses, ears and eyeballs that prevent any intrusion on the molecular level. Combined with the enhanced skin, a Gallifreyan can easily survive twice as long as a a human can in most hostile environments. With an oxygen supply this allows them to remain conscious for 6 minutes and survive up to 20 minutes in space unprotected. Without an oxygen supply they will only have 3 minutes of consciousness. Despite the above mentioned barriers, an unprotected Gallifreyan's eyes will be permanently destroyed if exposed to the cold and vacuum of space for too many minutes. Most humans are stronger then the average Gallifreyan (but, due to their second heart, and exposure to the Untempered Schism, Time Lords have incredible strength for their size) They can remain conscious when exposed to G-forces that would kill a human.

Gallifreyans need far less sleep than most humanoids. Popular concensus is that 1 hour sleep a day is more then enough. This is because a Gallifreyan can enter self-induced trance where they can ponder complex ideas without any outside distractions. 20 minutes in this state is equivalent to 8 hours of sleep for a human. Thus they only need about 1-6 hours of sleep every 2 days and they have the advantage of not requiring to take their rest in bulk. A ten minute doze here, a half hour snooze there, is a valid contribution to their three hour quota. While some become tired after only being awake for only 4 days, others have periods of hyperactivity followed by days of sleeping. While most prefer 1-3 hours of sleep a day, some Gallifreyans can even get by on a decade of sleep every 100 years. Gallifreyans might be able to sleep standing up. Gallifreyan's with only one heart will find that they need much more sleep then a two hearted Gallifreyan. Gallifreyans rarely dream, but when they do, they sometimes dream of choosing their next bodies, being able to fly, becoming the opposite sex, and bearing childrene. Because dreams can access the astral vortex, Gallifreyans who have nightmares (a very rare occurrence), or find themselves in near-death states, sometimes meet their Gods (Time, Death, Pain, etc). Often a deal or agreement is made and sometimes the Gallifreyan becomes that Eternal's Champion. Gallifreyan who have regenerated in that last few days will require a lot of sleep, even by human standards. 

REGENERATION - Telebiogenesis, Face-Lift

NOTE: Several sources claim that Time Lords are the only Gallifreyans who are capable of regeneration. But several other (equally valid) sources show normal (ie non-Time Lord) Gallifreyans regenerating without anyone considering it unusual. Depending on your point of view on this issue, one could argue that this section should be located on the Time Lord page and not the Gallifrey Biology page.

On a deserted world on the far edge of another galaxy Gallifrey's first space traveller, the Shobogan Tecteun, discovered a gateway to another dimension or inexplicable alternative universe. Near this gate she found a child (later known as the Doctor) who had been thrown through the gateway and abandoned. This child was capable of regenerating their entire body whenever they were on the point of death and became known as the Timeless Child. Like the Untempered Schism, the gateway might have surrounded the Child's body with bio-plasmic fields of regenerative chronon energy. Tectaun realized that the Child's abilities were connected to the immortal, self-regenerating nature of the Universe. The Timeless Child appeared to have timeless, perpetual, bodily regeneration (however he once claimed he could only regenerate 507 times).

Attempts to steal the Timeless Child's biogenic molecules and inject them into another species’ body immediately resulted in the creation of iron and silver crystals within the subject’s circulatory system – killing them within minutes. Studying the defiance of the thermodynamics of this phenomenon eventually led Tecteun to devise a way to safely splice into herself the genes nessecary to give her the ability to regenerate. In order to extend the already long Gallifreyan lifespan, the Shobogan leadership of Gallifrey decided that future generations of Gallifreyans living in the Citadel would have their DNA altered to give them the gift of regeneration (sometimes known as the Legacy of Rassilon).  Rassilon and Tecteun chose to limit the number of regenerations for this new race of Time Lords to only 12 (though this number would be expanded to well over 60 during the Time War). Some historians speculate that that Rassilon wanted this limit because he didn't want any Time Lord to become immortal and possibly become greater than him. At first only Time Lords were given the gift of regeneration, but later it would be shared with all Gallifreyans. All of them carry some of the child's genes. Virtually all records in the Matrix concerning the Timeless Child were later redacted leaving a fictitious history about the Immortality Virus being created by the biosynthesist named Thremix.

Modern Gallifreyan bodies are filled with an imprimature of self-replicating/regenerating bio-genetic molecules (sometimes known as the Immortality Virus, the Legacy of Rassilon). They can be found in every cell in their body. These permanently carried nanites work ceaselessly to repair and prune diseased, damaged,  malformed, and decaying cells. They also clean out arteries if too much fried food is eaten. Because of this it takes hundreds of years for a Gallifreyan to show signs of aging. Gallifreyans should avoid primitive germ decontamination technology as these 'germs' are half of the things that keep them alive. Gallifreyans usually recover from unconsciousness faster than humans and are immune to Dalek Nanogenes. The biogenic molecules allow the body to dispose of foreign objects and implants fairly quickly. The molecules are a variation of symbiotic nuclei and (probably using sonic waves) gives all Gallifreyans a symbiotic self-renewing cell structure. The biogenic molecules are aided by temporal platelets which cluster around any wound, accelerating time in that area to speed the healing. Gallifreyan's with only one heart will find their healing rates greatly slowed. If a Gallifreyan's symbiotic cell structure was ever deactivated they will not be able to regenerate.

When exposed to extreme pain or a sufficiently strong audio-visual barrage, a Gallifreyan will automatically retreat into a healing trance. With some training, it is also possible to voluntarily retreat into a healing trance. The mind will essentially switch off, and body will begin drawing large amounts of heat into the core of the body from the outside world. This thermal energy might have something to do with entropy manipulation, or perhaps it is used to power the biogenic molecules. Depending on the severity of the wounds, this heat transfer can cause the body's temperature to drop so far below zero that frost forms on the skin. Only one heart will continue to beat about once every 10 seconds. They will appear dead to most humanoids, but other Gallifreyans can tell they're alive. Using the trance, a fall from over 200 feet can be survived without losing consciousness or seriously breaking any bones. This is accomplished by a combination of bone relaxation and cellular break down and regeneration (similar to what happens in larval pupa). A healing trance allows most injuries (such as burns and diseases) to be healed in a day. A broken leg can heal in anywhere from a few hours to 4 days depending of the severity of the break. Most nonlethal bullet wounds heal in a day (the bullet is ejected from the body). Bullet grazes heal in a few hours as does the damage from some energy pistols. A combination of a bullet hole through the frontal lobe, a broken nose, jaw, femur, and collarbone will take a Gallifreyan 6 months to heal. While in the trance they can metabolize many types of poisons and drugs using Detox. It can take 23 days in a coma to deal with Polonium 210 poisoning. They can selectively regenerate specific organs while in the trance and (given several months) a Gallifreyan can grow a new heart (should one of their originals be removed). It might be possible for them to grow new limbs. If kept alive, a Gallifreyan’s severed body part can be used to detect whether that specific Gallifreyan is in the area. 

These rates of healing can be enhanced if the Gallifreyan is kept near (or inside) a TARDIS. Gallifreyan Medical Science has devices that can heal skin wound a few inches across in under half an hour. Bruises and cuts from a major brawl can be healed in 15 minutes. Their science can clone Gallifrey limbs from a single spit sample. It takes 2 days or less to create a hand. The patient must be sedated to have the limb re-attached, and the process leaves a thick pink scar at the seam. Unfortunately they can not regrow lost hands or limbs on humans because their technology isn't advanced enough yet. This is one of the few medical problems they haven't solved. For extensive body repair the patient's mind can be held in the Matrix for the duration of treatment. Gallifrey technology can't heal micro aneurysms inside a brain stem.

At age 8 every Gallifreyan is exposed to the Untempered Schism which surrounds their bodies with bio-plasmic fields of regenerative cronon energy. The bio-plasmic fields are distributed across their bodies but centered at the top of the spine. These fields protect a Time Lord as they travel from one time stream to another. Without exposure to the Untempered Schism Gallifreyans wouldn't have the energy for regeneration a Gallifreyan would eventually age and die. The fields of a Time Lord will protect their clothes (and the stuff in their pockets) from temporal shifts. These bio-plasmic fields have to be very active to adapt to the trauma of Regeneration. So much so that if a member of a lesser species is exposed to a Gallifreyan for several months the bio-fields will 'infect' them providing the same protection from the time stream, rejuvenating their cells and replace their telomeres. As a result the primitive will age very slowly and live for centuries. If this alien was to leave Gallifrey they will start to age at the rate of a year for every day.

It is possible, for a Gallifreyan to divert some of the chronon energy of their future regenerations from their bio-plasmic fields into a artron power cell or even another Gallifreyan. Such donations reduce the life-span of the Gallifreyan and, if the donation is big enough, runs the risk of causing error or even failures of future regenerations. When done with another person this process is known as genetic fusion, and allows the other Gallifrey to trigger the healing part of a regeneration, without fulling transforming into a new body. The transfer is not very efficient. A significant amount of regenerative energy is required to heal a broken wrist, and healing blindness could leave the Gallifrey missing some limbs or stature in a future regeneration. Healing a major bullet would use up an entire incarnation, and it would take all of the donor's unused regenerations to heal a major mortal wound. Even with Gallifreyan gene-splicing science this is still an imperfect and unreliable technique.

With the help of the biogenic molecules, a single body can last over 1,200 years. But if the body is subjected to great stress, such as a severed limb, extreme illness,(or perhaps extreme boredom) the limbic (or lindal) gland releases the hormone Lindos to trigger Regeneration. It is also possible for some (all?) Time Lords to will their own regeneration without stress or injury. It should be noted that Tecteun saw regeneration as a way for Gallifreyans to avoid aging and death. She didn’t intend for it to be used to escape violent death. While there is significant chance of regenerative failure when a regeneration is trigged by damage, a voluntary regeneration has a very high chance of success. Gallifreyans are educated in how to control their regenerations at their chapter's academy. By enacting the proper meditative techniques a Gallifreyan can temporarily delay the triggering of their regeneration. Most Gallifreyans can do this for 30 to 40 minutes but some can delay things at least a couple weeks. Chemical and telepathic signals from a trained Gallifreyan can be used to help trigger and guide someone who is badly wounded. But this will be ineffective on somebody who is conscious and refuses to regenerate. Under such circumstances, a regeneration can be forced using massive amounts of power (more then a TARDIS can produce). Such Forced Regenerations are used a punishment for many violations of Time Lord law. Forced Regenerations take longer to settle down and recover from then regular regenerations. Unfortunately, temporary post-regenerative amnesia often occurs if a regeneration is delayed too long after suffering a mortal wound, especially if they died first. This amnesia can last for several hours and give the Gallifreyan a paranoid and fearful attitude. Adrenalin can help with recovery from the amnesia. 

Gallifreyans who are exposed to the vacuum of space for several minutes, are unlikely to regenerate. But if they do, they will continue to regenerate over and over as the lack of air kills them, until their cycle is exhausted. Under such circumstances mutations are likely as the body tries to find a form that can exist in a vacuum. Likewise, Gallifreyans who have had both their hearts punctured or destroyed, suffer a disabling attack on their entire nervous system, or suffer a direct hit by a Dalek Neutraliser can not usually regenerate. It is possible to regenerate from a glancing hit by a Dalek Neutraliser. Large amounts of anaesthetic gas can delay or even stop the triggering of a regeneration. Some types of radiation exposure can interfere with or prevent regeneration. Exposure to dense time will weaken and age a Time Lord – possibly to the point where they will not survive a regeneration. Since the bio-plasmic fields are centered at the top of the spine, damage to that location can prevent regeneration. For this reason, regeneration after decapitation is unlikely but possible. If successful, the Gallifreyan will grow a new head (that will probably have the same memories as the original). Even if a Time Lord has had both hearts and all three brain stems stopped and been given a cellular shockwave to abort their regeneration there is still a remote possibility that life could be renewed in the body sometime in the next thousand years. This is because the individual cells in the corpse can often keep the body in a near death state for days while trying to regenerate. This can happen even if regeneration is impossible. Because of this Gallifreyans worry about being greviously injured while on another world since the locals might dispose of their body before a regeneration can occur.

Once triggered, the Lindos hormone travels throughout the Gallifreyan's body. The subject will begin to feel weak (especially if this is his first regeneration). As the body prepares to lose solidity, there will be a moment of hallucination (that can seem like hours to the Gallifreyan). At this point the Reset begins. The self-replicating biogenic molecules heal the body of its wounds, viruses, poisons, and aging, restoring its youth. In most cases, once all the cells have been healed, the regeneration of the body will proceed immediately. Its possible that the two stage Reset, then Regenerate process was implemented in the last few thousand years to purge the subject of alien contamination before creating the new body.

With great effort, it is possible for a Gallifreyan to temporarily delay the second phase of the regeneration for at least 30 minutes and occasionally a few hours, during which time they will slowly grow weaker as their body fails. Doing so can sometime cause minor alterations the Gallifreyan's physical appearance (this is why the Hartnell Doctor looks like David Bradely in Twice Upon a Time). Beyond this point the regenerative energy will have to be used or it will kill the Gallifreyan. If the second phase of the regeneration finally does go forward the result will generally be a 'slow explosion' regeneration that can cause a lot of collateral damage.  If the regeneration was triggered by an injury, and a suitable bio-matching receptacle (a spare hand that had been amputated for example) is available, the Gallifreyan can abort the Regeneration after the Reset process is complete by siphoning off all the extra energy into the receptacle. This is a rare occurrence as regeneration was never intended to be used to heal injuries (and bio-matching receptacles are rarely available).

After healing, the regeneration proceeds and the subject's body (and to a lesser degree the mind) will be completely restructured. The extra third strand of the tri-strand DNA was added by Rassilon to hold the elements that make Regeneration possible. This strand stores the regenerative information within the Gallifreyan's bio-plasmic morphic fields that surrounds their bodies. Empowered by the cronon energy from their exposure to the Untempered Schism, the regenerative information is conveyed from the destabilizing morphic fields to the biogenic molecules via a bio-language called Nucleolingua Symbiotica. If the subject is killed after the healing reset, but before the restructuring of the body, the rengeration is likely to fail and leave the Gallifreyan dead.

When a regeneration does occur the permanently carried self-replicated biogenic molecules rebuild the body in a violent biological eruption of artron energy. Normally this energy comes from the Lindos hormone, though other sources of artron energy can be used as well. The process usually begins with the hands. Using this energy every molecule in every cell is adjusted, displaced, rearranged causing a complete renewal and healing and consuming the rest of the energy. A regenerating Gallifreyan releases lots of heat. The burst of energy from a regeneration causes that area to be partially time locked. So, no matter how a Gallifreyan's history is altered, it will have a tendency to be put back on track when they reach the moment of their regeneration. Regeneration also restructures the biodata of the subject, thus it could affect the subjects past as well as its future. Because of this some Time Lords will catch glimpses of their entire past and future during the final tremors of their regeneration. This is known as a Memory Vortex. Most regenerations take between 10 seconds and 2 minutes and release a great deal of heat.

In any event, Regeneration is an exhilarating experience akin to driving a car very very fast. Some find the event to be filled with images of horror from their own past, and have compared the regeneration experiance to a bad LSD trip. During this time some of the old neural pathways close and many new ones are created. A blinded Gallifreyan will regain their sight after after a regeneration if the neural pathways controlling his sight are intact. Even damaged synapses are repaired. At the first regeneration the nanomachines are programmed to build into the new body a number of improvements and backup systems including a new heart. For this reason the first regeneration is usually the most painful. At the end of the regeneration the comatose Gallifreyan is awakened with by an automatically triggered electroencephalographic shock. But a particularly stressful regeneration will leave the Gallifreyan unconscious for over an hour. Gallifreyans typically have no memory of the exact moment of their regeneration. It takes about 10-60 minutes for the body to "gel" completely which allows Gallifreyans of New Blood Houses some time to try various genetic configurations and chose their physical forms. Things like hair length can sometimes alter multiple times over the next few days due to regeneration. If a Gallifreyan develops an immunity to a virus that immunity will persist in each new incarnation.

When a child regenerates their new body is also a childe’s body. However it is very dangerous for Gallifreyans who haven't passed First Maturation (ie teenagers) to regenerate. For this reason it is usually forbidden for Gallifreyans to regenerate until they are 500 years old.

For most Gallifreyans of the Old Blood Houses the form of their body is out of their conscious control, and instead picked by their subconscious. Gallifreyans of some house tend to keep the same racial and sex characteristics through most, but not necessarily all, of their incarnations. The Gallifreyan will often find that with a new body comes new levels of awareness, coordination, and physical strength. The amount of trauma and/or stress a Gallifrey is experiencing has been know to exacerbate the degree of physical change the subject undergoes.  Occasionally two different Gallifreyans will end up with bodies that look the same. This has been witnessed on at least 1 (or 2, or 3) occasions. On other occasions Time Lords have copied the bodies of humans they have seen. Under some circumstances an adult Gallifreyan can regenerated into a childe. It is possible for a Gallifreyan's sex to change during regeneration if the regeneration is particularly traumatic (often if the Gallifreyan regenerates by choosing to committing suicide). This is known as a Sex Change Regeneration. Approximately 10% of Gallifrey's population is female.

Gallifreyans from Newblood Houses have amazing control over there regenerations which allows them to try on several different genetic templates (and appearances) during the first 60 minutes of a regeneration. This technique can be taught with some success to Gallifreyans from the Old Blood Houses. Some are even capable of temporarily regenerating their genetic makeup enough to fool some types of gene scanners without inducing a regeneration, but this consume a lot of chronon energy. Forced Regenerations take even longer to settle down and recover from then regular regenerations.

While Regeneration often causes temporary memory gaps the new body should have all the same memories. However, because of the new personality, he will tend to draw different conclusions from those remembered experiences. Gallifreyans often find remembering events that occurred to previous incarnations causes headaches. While most levels of skill and abbility remain the same, some changes are possible. After regeneration, Gallifreyans often don’t know which skills they’ve kept and which ones’ they’ve ‘lost’ until they try to use the skill. It appears that many hand/eye coordination skills need to be "relearned" (at a fairly quick rate) due to the difference in body design. A Gallifreyan's handwriting remains more or less the same throughout all of their incarnations. After violating the 7th Law of Time, it’s possible that any regeneration blocks any lingering memories a Gallifreyan has of events from his own future.

Due to the chemical changes in their brain, and the opening and closing of neural pathways, the new body will often appear to have a different personality. This personality is often heavily emphasized for the first few hours. In truth, the new personality is simply the expression of a different aspect of their fundamental personality. Again, the amount of change often correlates to the level of stress/trauma that caused the regeneration.

After a regeneration, a copy of the previous personality is stored in the memory space for eventual transfer into the Matrix. Officially each copy is kept 'sleeping' in their minds, but in reality some of them become Guardians of the Edge. They function as gatekeepers for the point of no return that a Gallifreyan mind crosses when a regeneration occurs. Past incarnations sometimes wish they could have lived longer. Some struggle so much they need to be locked away in a mental room with no doors. In very rare cases of Regenerative Dissonance the copies of the previous personalities are left active and have just as much control over the Gallifreyan as the current personality. Most Gallifreyans with this condition quickly arrange a permanent suicide - usually before their seventh incarnation. However the Time Lord sometimes known as the Twelve successfully reached her 12th incarnation. Some Time Lords of the first rank can intentionally achieve a temporary mental Retro-Regeneration and temporarily summon the skills and personality of a former incarnation. A TARDIS's Telepathic Circuits can help a Time Lord achieve this. As the number of personalities build up in the subconscious the Gallifreyan mind can risk breaking under the strain. There is also Gallifreyan Technology that allows a Time Lord to borrow biodata from their own future to overcome a current physical or mental disability for 20 minutes. But it dangerous to use. Possible complications include: all future incarnations having the same disability, the loss of the ability to ever regenerate, or burning out the user’s brain and killing them at the end of the 20 minutes.

The random nature of regeneration terrifies most Old Blood Gallifreyans. Until recently Regeneration was still a relatively risky procedure. While regenerating a Gallifreyan's body might be infiltrated foreign materials it comes in contact with. The biogenic molecules might incorporate the foreign material allowing the Gallifreyan to change species. Thus a Gallifreyan could regenerate and find himself to be half human. It is also possible for them to regenerated in an animal like a talking dog (which could change breeds with every subsequent regeneration) or a cat. Originally the more primative regeneration cycles would lead to contamination when a Gallifreyan regenerated on an alien world. The local biosphere and morphic feilds of the world would turn them into new creatures that were adapted to that environment. Legends tell of regenerations that had only regenerated half of the body (which can happen if the subject regenerates in a strong time dilation field), regenerations where the body was changed but not the brain, regenerations that turned the subject inside out, regenerations that reverted the Gallifreyan into a time-tot and other monstrous variations. There are rumors and heresies that, at one point in Gallifrey's history, a Shadow House existed which would hold Gallifreyans whose regenerations have failed in some way. These problems were only corrected within the last several thousand years. It was Tecteun herself who revised things so that Gallifreyans will always stay Gallifreyan, no matter what environment they regenerate in. The Reset phase of regeneration might have been implemented to purge the body of any mutations caused by from contaminating biodata. Now physical contamination only leads to the development of severe allergies (for example to gases in the praxis range or extremely humid air). Even with the Reset, regeneration destabilized their morphic fields comprimising their immune systems. This makes their biodata vulnerable to paradox viruses or other types of minor temporal paradox, which can lead to all sorts of complications. Damaged genetics during a regeneration can leave the subject with unstable DNA leading to cellular degradation. This requires frequent consumption of the artron life energy of others to survive, but with each live consumed the period of stability shortens. Major injuries can lead to a potentially fatal regenerative collapse. The Free Time organization created the Dogma Virus. This virus would remain dormant in Gallifreyans until they regenerated, at which point the subject’s new incarnaiton turned into a violent mindless being.

After regenerating most Gallifreyans will retreat into a healing trance for up to 6 hours. Particularly violent incidents generally require more time in the trance. A Gallifreyan's blood pressure can drop to 70/70 millimeters of mercury during this time. Waking a Gallifreyan from this healing trance can cause a neural implosion, which significantly increases the amount of time the trance will be needed. While sleep and healing trances are perfectly safe, being violently rendered unconscious shortly after a regeneration can induce a second regeneration. A Compressed Sleep Unit can reduce a Gallifreyan's time in a healing trance - sometimes to mere minutes. Within the first 15 hours of regeneration a Gallifreyan will still have enough residual cellular energy to cause several unpredictable effects. This energy can be used to heal many types of physical damage. Deadly falls, and multiple bullet wounds will heal near instantly, and they might be able to survive a gun shot to the head. Recovery is fast enough that even severed arteries generaly won't have time to bleed. They can even regrow a severed body part, such as a hand. The energy can be discharged causing destructive effects to people or objects that are hit by it. The new body part might be designed to prevent whatever caused the loss of the original. Shortly after regeneration Gallifreyans will often experience bursts of superhuman strength and speed while the new body stabilizes.

Regeneration is quite energy draining and Gallifreyans will often need to consume large meals to return to their normal biological energy levels. They often find their own minds to be tricky to navigate after a regeneration. Because their body is still working on overdrive many Gallifreyans also experience disorientation and confusion due to the ambient complexity of the area. The ambient complexity consists of the number of sapient minds in the local area (which generate psionic fields) and the amount of technology (which generates electro-magnetic fields). If the Gallifreyan regenerated in an environment with excessive ambient complexity it can cause a Regenerative Failure. And even after the regeneration has been completed, ambient complexity can causes erratic and volatile mood changes. While extreme heat combined with adrenalin can temporarily stabilize a newly regenerated mind and recover from amnesia, the only reliable way to halt the failure is to move the subject to a zero environment. Once in a Zero Room, a Time Lord can enter a healing trance while waiting for their body to stabilize. 

It is very rare that the environment on Gallifrey or inside a TARDIS will trigger regenerative failure and its almost unheard of inside the dome of the Capitol. But forced regenerations (whether by violence or other means) generally leave the subject in an extremely erratic mental state for some time. In some cases Post-Regenerative Trauma can cause severe personality instability. This can even leave them permanently psychotic and under the control of the dark side of their mind. In most cases the Gallifreyan's mind will synchronize properly within 4 days returning their strength, reflexes, and personality to normal (for their new incarnation). Sometimes, in the absence of a Zero Room, the subject never synchronizes properly. Both Metamorphic Symbiosis Regenerators and Zero Rooms can assist with regenerative trauma and ambient complexity. The numismaton gas found in the Elixir of Life on Karn can also solve a variety of regeneration problems by assisting in the mutations of the subject's genetic structure. Anesthetic can delay or destroy the regenerative process and cause post-regenerative amnesia.

For all these reasons regenerations are usually planned months to years before the actual event. A low-grade telepathic field (like the inside of a TARDIS or a boost generated by another Gallifreyan) is essential to ensure survival during a regeneration especially if the subject has suffered radiation damage. Without such assistance an injured Gallifrey runs the risk of the regeneration aborting halfway through leaving the subject looking like some sort of multi-limbed monster, and destroying their ability to regenerated again.

Going through 7 regenerations in less then 700 years is considered to be incredibly wasteful, but some seedy Gallifreyan Cardinals hang themselves to get rid of extra regenerations. This is considered to be a dangerous hobby. For these reasons there's a fair amount of "regeneration politics" among certain factions on Gallifrey. These focus on issues of class, gender, and species. Sex Change Regenerations are possible, (probably by splitting a males diploid cells into haploids). Each body is referred to as an "incarnation" or a "life-span". Public discussions of regeneration among Gallifreyans appears to be similar to sex amongst humans (i.e. not good table manners). Regeneration is considered to be a private matter - not to be witnessed by others (artificial or otherwise) and are generally conducted in a very quiet location. However a loom automatically records the genetic metamorphosis every time one of its cousins regenerates. 

Each body can last centuries. While Gallifreyans only need to regenerated every thousand years or so, it is possible, with rejuvenation and care, to get 10,000 years out of each incarnation. Most Gallifreyans will notice their bodies slowing down and reduced stamina after two to three hundred years. CIA Field Agents tend to go through a life-span approximately every 150 years. It should also be noted that the last few life-spans generally don't last as long as the earlier bodies. This is because elderly Gallifreyans tend to regenerate more often in an attempt to dispel physical and mental malaise. With every regeneration more of the nucleolingua symbiotica is consumed. Thus it is possible to determine how many remaining incarnations a Gallifreyan has by measuring the amount of Nucleolingua Symbiotica remaining in the tri-strand DNA. The last few regenerations of a cycle appear to produce much more excess energy, enough to severely damage a TARDIS control room.

As the number of personalities build up in the subconscious the Gallifreyan mind eventually risks breaking under the strain. Because of this tendency towards madness, Tecteun engineered it so that the nucleolingua symbiotica can only divide 12 times before the biogenic molecules become unstable and decay - limiting a Gallifreyan to 13 bodies. As a result Gallifreyan minds and bodies can only withstand the strain of 12 regenerations. If a Gallifreyan suffers a severe enough injury in his 13th body, a regeneration will be triggered, but its inevitable failure will kill the subject. Some historians speculate that that Rassilon set up this automatic decay because he didn't want any Time Lord to become immortal and possibly become greater than him. During the Time War the number of regenerations availible to a Time Warrior would be expanded safely to well over 60.

Bi-generations are an ancient Time Lord myth. The story says that, after the reset phase, the Gallifreyan will split into two independent Gallifreyans - one with the healed body of the original, and another, fully regenerated form. Both Gallifreyans will have the same memories.  The only known bi-generations to have actually occurred happened to the Timeless Child. When a bi-generation occurs it can have a retro-active effect causing everyone of a Gallifreyan’s previous regenerations to be replaced with bi-generations – creating numerous duplicates of that Gallifreyan. It’s possible that the original body(s) will eventually fade away after several years. It’s also possible that this could be the natural form of reproduction of the species of the Timeless Child.

Esoterium is a psionically active element that is extremely toxic to Gallifreyans but harmless to humans. It can be used to create a weapon that will destabilise a Gallifreyan's morphic print. This will leave them in a permanent state of random degeneration. Some frequencies of radiation or forms of hyperspace stress can have a similar effect. Whatever the triggering incident the subject will be physically regressed back through previous incarnations. This occurs because the Gallifreyan's body is instinctively trying to find a stable morphic print. The interior of TARDIS or similar stabilizing facility such as a Metamorphic Symbiosis Regenerator, can sometime slow this phenomenon, as can exposure to another Gallifreyan's morphic field. A personal morphic stabilizer can be used to allow the Gallifreyan stability and mobility but is only a temporary fix. A Force Regeneration can be used to imprint a Matrix projection of another Gallifreyen on to the subject – effectively bringing a deceased Gallifreyan back to life.

With rejuvenation and care a Gallifreyan could get up to 10,000 years of mobility out of each incarnation. And technically Gallifreyans can force themselves to stay alive indefinitely, making them immortal except for accidents. But by age 12,000 most Gallifreyans are suffering from severe senility and forgetfulness, for this reason, they usually choose there final Death Day between 7,000 and 12,000 (usually at about age 10,000). Triggering a 13th Regeneration might be the accepted way that Gallifreyan's end their lives.

It is possible to surgically implant a new regenerative cycle by manipulating the Nucleolingua Symbiotica, but this can only be done with the permission of the entire High Council. Such a field can even regenerate a Gallifreyan who has exhausted their capability of regenerating, while simultaniously bestowing an entirely new regeneration cycle. This is probably achieved using a Metamorphic Symbiosis Regenerator (which can provide unlimited regenerations). The regeneration cycle can also be renewed by recharging the chronon energy of their bio-plasmic fields. This recharging requires a massive amounts of carefully modulated and controled chronon energy. Recharging a regeneration cycle requires almost the entire output of the Eye of Harmony (though only for a short amount of time). Time Lords who have used up their regenerative cycle have been known to hook themselves up to their TARDIS to try to induce a pseudo-regeneration but this will almost certainly leave them in an endless regenerating cycle until they are disconnected from the TARDIS and die. Using cryogenetic extraction and an elysian field, it is possible to break a Gallifreyan down to the atomic level and reconstruct them with an altered nature and personality. A side-effect of this process renews a subject’s regeneration cycle. The process works by using a temporal touniquet to sever the new incarnation from the old Gallifreyan’s biodata. No only will this damage many of the subject’s memories of their previous lives, but it makes them into a temporal paradox.  As such the process is a violation of several Gallifreyan laws. Renegade Gallifreyans have also been know to renew their regenerative cycle by "Jumping Looms" (being reborn into a new Family), though this process generally result in a loss of most of the renegade's memories. With all of these techniques, a Time Lord might be able to regenerate many more times, but probably at the cost of their sanity. If Gallifreyan receives a new cycle of regenerations, the gap between the healing reset and the actual first regeneration tends to be on the order of several minutes instead of seconds. This delay will cease once the new cycle is properly broken in.

A catalytic distillation and extraction chamber (which uses a hadron socket) can be used to collect up a Gallifreyan’s life-force (and thus steal their future regenerations) if it is applied as soon as the Gallifreyan begin to regenerate. A Distillation Gun is a handheld weapon that will remove one to three regenerations from the targeted Gallifreyan per hit. In theory it is also possible to extract an existing regeneration cycle from a Gallifreyan using surgery. To do so the relevant chains for each incarnation would have to be isolated and drawn off – removing that regeneration. This extracted cycle could then be implanted in a new subject. Some have speculated that it might be possible to bypass Rassilon’s death trigger by distilling the corrupted nucleolingua symbiotica of a Gallifreyan in his 13th body.

A Genetic Manipulation Device (GMD) appears to use the same principles of regeneration only the technology is external to the subject. Using a sonic micro-field manipulator the GMD creates hypersonic waves. These sound waves create a state of resonance in the subject, which destabilizes the subject's cell structure and DNA. If the subjects biological code is programed into the manipulator, a metegenic program can then hack into the subjects genes, manipulate the coding in the protein strands, and program them to regenerate. This technology can also be used to prevent regeneration or hyper-age a Gallifreyan. A GMD can be built into a Laser Screwdriver to be used as a weapon.