Master from Mars (John Christopher Tripods novels)

Masters a.k.a. Tripods

(Tripods Quadrology by J. Christopher)


The Tripods is a YA post-apocalyptic novels series by John Christopher. I suppose you could see it as an ancestor to the series that made it during the 2000s and beyond, such as Hunger Games, Divergent or The Fifth Wave. The three core books were published in 1967/68.

In various respects it draws from über-classic The War of the Worlds.

This profile has S P O I L E R S about all things Masters.



  • Group Affiliation: The Masters.
  • Base Of Operations: Mobile, usually tied to their current vessel or city.
  • Height: 10’ Weight: 600 lbs. Age: Varies, can be 100+ years.
  • Eyes: Green Hair: None

Powers and Abilities

The Masters themselves have impressive strength and durability compared to human. This is due to the heavy build necessary to move in the naturally higher gravity of their homeworld.

The Masters’ natural atmosphere is a hot, humid, green murk. The Masters cannot breathe the Earth’s air any more than humans can breathe the Masters’ air. It is unknown whether the Masters are actually poisoned by Earth’s air like humans are by the Masters’ air. Perhaps it simply lacks the necessary components for them to breathe it.

It is known that neither species finds the other’s atmosphere caustic. A simple helmet with an internal air supply or environmental filters is enough for humans to breathe the Masters’ air. The Masters likewise only need a helmet to provide life support in Terran environments.


Masters still wear full environmental suits when they go outside on Earth. But this is due to finding the sunlight irritating, being much more intense than in their preferred dimly-lit habitat. This sensitivity to sunlight does not seem to be any worse than that of humans with lighter skin tones who sunburn easily.

The Masters’ average lifespan is much longer than that of humans. At least some of the Masters who were on Earth when the occupation ended had been members of the original exploratory crew that discovered Earth. These were thus well over a century old with no apparent sign of being hindered by advanced age.

Weak points

There are two weak points of the Masters’ physiology that can be exploited by humans. The first is a soft spot between their upper and lower mouths. This point is extremely sensitive to impacts. A single punch to this spot by a 15-year-old boy in good physical condition was enough to instantly kill a Master.

Masters are also vulnerable to alcohol, being incapacitated for hours after drinking a small amount. While Masters’ senses can usually sense potentially dangerous adulterants in their food, alcohol somehow escapes such detection. This makes it a highly effective poison against the Masters.

Masters also need to drink a great deal more water than humans and to keep their skin moist. This motivates them to frequently soak in pools. It is unknown how long a Master could go without wetting their skin or how quickly and seriously dehydration would affect them.

The will of the Masters

The Masters’ primary tool in their initial domination of Earth was a hypnotic electromagnetic signal. This signal was first sent over standard television transmissions, undetectably encoded into the broadcast.

This signal was possibly reinforced by the imagery of those broadcasts. It featured non-threatening and heroic images of the Tripods. These were all humanity had seen of the Masters at that point.

This hidden signal slowly enslaved the show’s viewers. This made them worship the Tripods as bringers of peace, and then compelled them to gather at the places where the second wave of Tripods would eventually land.

It was during the second landing that the Masters made Caps available to their followers. The followers donned the Caps, which received and reinforced the Masters’ hypnotic signals.

This was critical because the hypnotic suggestions sent over the television broadcasts would fade within a few days without continued exposure. By contrast, the Caps provided constant exposure and apparently at a stronger level than the subtler embedded television signals. The Masters’ followers then mass-produced the Caps, which was easily done since they were essentially simple antennas.

Whom the cap fits, part 1

Those who had the Caps placed on their heads were immediately converted, becoming unquestioningly obedient to the Masters. Furthermore, once applied, a Cap could not be removed without rendering the subject permanently mentally disabled. The unCapped person would thereafter only function at a low level of cognitive ability.

These were simple devices that received the Masters’ signals and fed them directly into the wearer’s brain. The first Caps were rubberized head pieces with a thin metal webbing that served as an antenna.

Later, after their dominion of Earth was complete, the Masters would surgically attach the Caps directly to their subjects’ shaved craniums. Once a subject’s hair grew back, the Cap was barely visible as a metallic spider web on the scalp.

In both cases, the Caps were fairly simple. Thus, they could be easily disabled by clipping certain relays. This allowed free people to render the Caps harmless and then wear them without being bent to the Masters’ will. Which in turn let them move among the Capped without arousing suspicion.

After the Masters had subjugated humanity, they began a more intricate Capping process. Tripods would visit each human village once a year, a date known at the village as Capping Day. On that day, any children in the village who had reached 14 years of age would have their head shaved, be taken into the Tripod, and have a Cap surgically grafted to their heads.

One in 20 of these procedures would fail, rendering the person a Vagrant. Vagrants are mentally disabled persons with a tendency toward wanderlust.

Whom the cap fits, part 2

The resistance speculated that Vagrants were weak-minded people whose psyches were crushed by the Masters’ domination. Either that, or they were strong-willed people who suffered brain damage trying to fight the Masters’ control.

There was no evidence supporting either supposition. The idea of an innate quality may be contradicted by the fact that some people became Vagrants only after the Cap’s signal was disrupted in the wake of the Masters’ cities being disabled.

Given all of the above, it may simply be that Capping and the Masters’ hypnotism signals are not completely compatible with human neurology. As a result, any application or change in the use of those devices carries a risk of damage to the subject.

This hypnotic ability appears to be an aspect of the Masters’ technology rather than a natural ability of the Masters themselves. It was certainly dependent on their machinery. In addition to requiring electronic receivers for the signals to work, the Capped were no longer under hypnotic compulsion once their region’s city’s power generator was turned off.

Furthermore, the falsely-Capped spies never felt any unusual compelling power from the Masters themselves. It is possible that the Masters’ technology only enhanced an innate psionic  ability of theirs. Such devices have long been featured in comic books and science fiction novels. But the simplest explanation is that the Masters’ hypnotic abilities are technological in nature.


It is the technology of the Masters that elevates them far above modern humanity. Their vessels are capable of interstellar travel at near-light speed and can support their crew for hundreds of years.

The first vessel of the Masters had sufficient resources to conduct the conquest of Earth and the subsequent century-long dominion, including the establishment of three large cities, without any known logistical support.

The Tripods, part 1

The Tripods were 50 foot wide metallic grayish-green hemispheres, flat side down. They sported three equidistantly placed stilt-like legs, each of which were approximately 60 to 70 feet long. The legs were attached to the Tripod by a circumferential ring running along the bottom edge of the hemisphere.

There were springs and segments between the ring and the hemisphere and at the joints of the legs. These allowed the legs to lengthen and shorten as necessary to keep the hemisphere level and compensate for the jolt of the legs’ stride.

There were two rows of evenly spaced glassy green panels running along the side of the hemisphere. These gave an impression that was a cross between staring eyes and a leering grin.

Access to the inside of a Tripod could be made through two portals. The first portal was a lens-like orifice in the center of the hemisphere’s bottom. It was commonly used for objects brought into the Tripod for detailed examination or surgical procedures such as Capping.

The second was a door amongst the rows of viewports that slid up, allowing people to enter a small airlock. This was used when the Tripod was simply conveying people such as the slaves that worked in the cities. The second door, in conjunction with the glassy panels, looked somewhat like a mouth when open.

The Tripods, part 2

Each Tripod has three manipulative appendages. These are silvery tentacles extending from the bottom of the hemisphere that stretched at least 100 feet. The tentacles were retractable.

Normally only one or two were deployed, using only the minimum number necessary for the task at hand. A single tentacle was strong enough to lift and crush a British Challenger tank. It also was dexterous enough to snare a fleeing man or pluck a rider off of a running horse.

Tripods could navigate at night by virtue of a series of built-in bright white spotlights. When deployed near coastal areas, Tripods were equipped with flotation devices on their feet, which allowed them to stride upon the water. In DC Heroes RPG terms, treat this as Swimming: 05 with the Limitation: only on water’s surface.

Though they were not dedicated war machines, the Tripods were reasonably durable. The exterior armor could withstand light infantry weaponry up to the level of grenades without harm. A single grenade or similar explosive placed inside a Tripod (thrown through one of the portals, for example) was sufficient to disable it and kill the crew, however.

A hit with a single standard air-to-surface missile was also enough to destroy a Tripod. Tripods were also equipped with beam weapons which could harmlessly render a person unconscious. This was extremely useful when capturing a human subject for research or surgical implantation.

Tripods normally had a crew of four, but they could be operated by remote if desired. This was standard procedure during the initial landings, in which the Tripods were expected to be destroyed. After the conquest of Earth was complete, manned Tripods became the standard.

There were smaller variants such as those used in Sphere Chases. Therefore, the GM could introduce lesser Tripods with fewer APs Growth and an attendant reduction in STR, BOD, and Extra Limb.

Mastery of the Mind

Though there was no direct evidence that the Masters had psionic powers, there was an unexplained occurrence that hinted at this possibility. When the Masters finally abandoned Earth, Ruki, the last living Master on the planet, seemed to somehow sense that he had been left behind. He passed away at that moment in the cell where he had been held captive for several years.

This could be indicative of some weak sense of other Masters, or some unknown technological communication ability. Or it might simply be an exaggeration of coincidence. The event is relayed second-hand at best in the novel.

It should be noted that the Masters never otherwise demonstrated any ability to sense or communicate with one another psionically. For example, Ruki was never able to summon help during his captivity.

The means by which Ruki died are also unknown. It may be the case that Masters have sufficient biocontrol to shut themselves down. Or they may have an implanted device that allows them to do so. Again, that’s assuming Ruki’s death was truly related to the Masters’ departure and not simply a coincidence.


(The Masters are referred as the Tripods throughout most of this history. This was how they were known to humanity for almost their entire time on Earth. Indeed, for most of the Masters’ occupation of the planet it was unknown to humanity whether the Tripods were vehicles housing aliens or if they were instead giant robots.)

The first appearance of the Tripods was considered more of a curiosity than a threat. Three Tripods appeared simultaneously across the globe by unknown means. These manifested in the state of Montana in the USA, near Dartmoor in England, and in Kazakhstan in the USSR.

The Tripod in the USSR was immediately attacked and easily destroyed. The Tripod in England smashed several farm buildings, took a farmer inside, and then attacked the responding British Army forces, which promptly destroyed that Tripod. The Tripod in the United States self-destructed shortly thereafter.

No alien lifeforms or useful technology survived within the Tripods’ wreckage. The only clue left behind regarding the Tripods’ intentions was the corpse of the farmer seized by the Tripod in England. The body had apparently undergone a partial autopsy after being drawn into the Tripod. The autopsy appeared to have focused on the victim’s head.

Television, the drug of a nation

The attack of the Tripods quickly became a memory when no further appearances occurred. It then re-emerged as a pop culture fad. The Trippy Show, a cartoon featuring Tripods as harmless figures, became a global hit.

The cartoon’s stories revolved around traditional heroic narratives that cast the usual heroic icons in a pejorative light. Then Trippy the Tripod would step in and save the day.

Fans of the show became known as Trippies. They became seriously attached to it. There were an increasing number of incidents in which fans who were prevented from watching the cartoon carried out violent antisocial and even homicidal behavior against those who had denied them their viewing opportunities.

It was speculated by some that the Tripods were sending hypnotic signals through the cartoon to subvert the wills of the audience. This hypothesis was confirmed when thousands of Trippies around the globe began congregating in specific locations. There, they were greeted by a second wave of Tripods.


This wave was much more numerous. It was estimated that there was approximately one Tripod for every 10 million people, each Tripod near a major population center. Trippies were taken into the Tripods and then released.

Most of the Trippies then dispersed, except for a remaining core group around each Tripod. The Tripods then began moving toward the cities nearby with Trippies clinging to their legs as human shields. Most military forces around the globe were not deterred by this measure and quickly destroyed the latest wave of Tripods.

Unfortunately for the human race, the Tripods’ true mission had already been accomplished. The Trippies had dispersed far and wide with Caps. These were simple devices that received the Tripods’ signals. When placed on a victim’s head, Caps subverted people to the Tripods’ will.

War broke out between the increasing ranks of the Capped and the dwindling forces of the free. This war, the free ultimately lost. Most of humanity was eventually capped. A few pockets of resistance hid out in high mountainous areas in which the Tripods either chose not to or could not travel.


Having conquered the world, the Tripods established three cities for themselves. Each one was a massive edifice with golden walls that rose 200 feet high around them, capped by thick green translucent domes. One city was located on the western coast of Asia, one in Central America, and one in northeastern Europe.

The Capped shifted to a pre-Industrial Age/medieval lifestyle. They abandoned the cities of old for agrarian villages. The human race’s numbers had been severely reduced by the war between the Capped and the free, and that number was further lowered when the Tripods simply ordered many of the Capped to let themselves starve.

This reduced humanity’s population enough that the remaining humans could be fed by the lower level of agricultural technology at which they were now living.

Many of the Capped served as slave labor for the Tripods, either in mines or within the cities. The resistance kept to the mountains. They sent out covert agents to recruit young people before they were Capped. And they bid their time as they sought information that could be used to defeat the Tripods.


A century passed as the resistance slowly gathered numbers and information. Eventually, it was felt that the free human groups had enough resources to begin fighting back against the Tripods in earnest.

The first step was to gather more extensive intelligence on them. This was done by arranging for a few falsely-Capped young men to become slaves of the Tripods. These infiltrators were taken into one of their cities, each of which kept a population of 500 to 600 human laborers.

These spies gathered a wealth of data regarding the Tripods. First and foremost, the Tripods were only vehicles for the Masters. These were an alien race that sought to change the Earth for their own use.

The spies were horrified to learn that the Masters intended to change Earth’s environment to one closer to the Masters’ homeworld. This would make the atmosphere toxic to native Earth life.

The machinery to do this was already on its way and would arrive in four years. Ten years after that the Masters’ xenoforming would be complete. But every living thing on Earth except the alien conquerors would die long before that due to the increasingly poisonous air.


The spies escaped the city and returned to the resistance, warning them of the imminent threat to humanity. The resistance supplemented the spies’ information by disabling a Tripod and capturing a Master. They used the environmental samples recovered from the Masters’ city to build an enclosure that would keep the Master alive.

The captured Master, Ruki, was inadvertently given a spiked drink, revealing the Masters’ unique weakness to alcohol.

With this information in hand, and bearing in mind that the resistance would only have one chance to overcome the Masters, the rebels spent the next two and a half years coordinating with other movements across the world. The goal was to attack all three of the Masters’ cities simultaneously.

The resistance plot involved sending saboteurs in through the same water drainage systems that let the spies escape. The operatives would spike the Masters’ water with alcohol before opening the cities’ airlocks and letting the poisonous Terran atmosphere in.


In two of the three cities the sabotage went as planned and the Masters therein were killed. Those Masters outside in Tripods died a few hours later for reasons unknown.

The attempts to destroy the American city failed. So did a subsequent plane attack to crack that city’s dome when the Masters used an EMP  burst to shut down the planes in mid-flight. Six months later, a final attack by aerial balloons carrying bombs managed to break the dome and kill the Masters inside.

One year later, the Masters’ xenoforming ship arrived. It was a monstrous vehicle one mile long and a quarter-mile wide that was visible from orbit. The ship did not attempt to invade. Instead, it simply bombed the cities from orbit, apparently to prevent humanity from further researching the Masters’ technology. It then disappeared.

At the moment the ship vanished, the last Master on Earth, the captive Ruki, quietly expired in his cell.


“They stood much taller than a man, nearly twice as tall, and were thick in proportion. Their bodies were wider at the bottom than the top, four or five feet around I thought, but tapered upward to something like a foot in circumference at the head…if it was a head, for there was no break in continuity, no sign of a neck.

“The next thing I noticed was that their bodies were supported not on two legs but three, these being thick but short. Matching them were three arms, or rather tentacles, issuing from a point about halfway up their bodies.

“And their eyes — I saw that there were three of those, too, set in a flattened triangle, one above and between the other two, a foot or so below the crown. The creatures were green, though I saw that the shades differed, some being quite dark, the green tinged with brown, and others quite pallid.” (from The City of Gold and Lead)

Below the eyes are two mouths. The upper one is used for respiration and speech, while the lower one is for intake of food and drink. The Masters did not wear clothing, other than environmental suits when necessary.


The Masters are very long-lived compared to humans. This leads them to be more patient and to plan over many years. When the Masters’ exploratory vessel discovered Earth, the crew was content to conduct a survey for several years before beginning their subversion of humanity.

The Masters tended to be staid and asocial. They gathered in groups only when necessitated by a particular activity. This may have been a cultural trait rather than an innate part of the Masters’ psychological makeup, since some Masters were more socially inclined. Some even seemed somewhat disheartened at the lack of opportunities to mingle.

Such Masters would even freely talk with human slaves when the opportunity arose. The closest thing to social grouping in the Masters’ culture was a tendency for some Masters to prefer physical action while others preferred more intellectual pursuits.

Regardless of where a Master fell in this spectrum, most of them enjoyed the sphere chase. This was a ball game played using small specialized tripods. When not gathered to watch sphere chase games and exchange information on various subjects (the Masters’ equivalent of small talk), they entertained themselves by relaxing in small garden pools at home.

Masters also liked inhaling a special gas from small transparent bubbles.

Other traits

The limited social interaction of the Masters expresses itself in their humor. It tends to be exceedingly dry on the rare occasion that they exhibit it. Though they used deceptive techniques in their subversion of humanity, the Masters do not do so in their interactions with one another.

They only lie by omission. Furthermore, they trouble differentiating between the human concepts of a fictional story meant to entertain or educate and a falsehood meant to deceive. But they do have a sense of aesthetics. Thus, some Masters sought to keep certain Terran lifeforms in preserves even after xenoforming the planet.

The attitudes of Masters toward humans varied from seeing them as vermin, to exploiting them as beasts of burden, to appreciating them as beloved pets. The Masters with the former attitude tended to look at those Masters with personal slaves as degrading themselves by their association with such animals.

The high gravity and heat of the Masters’ environment in the cities was sufficient to erode the health of even the most extremely physically fit and youthful slaves within two to three years. Therefore, the Masters thoughtfully provided incineration chambers for slaves to euthanize themselves when they could no longer properly serve their owners.

In keeping with the appreciation of beauty noted above, some Masters would have the bodies of particularly attractive slaves preserved for exhibition alongside other museum artifacts.

DC Universe History

The Masters could conduct a similar campaign of conquest in the DCU. It might be even easier to do so with the increasing ubiquity of telecommunications.

As with any other mind control scenario, having the PCs face controlled innocents can provide challenges in stopping the invaders without harming their thralls.

Game Stats — DC Heroes RPG

Tell me more about the game stats

The Masters

Dex: 04 Str: 05 Bod: 06 Motivation: Power Lust
Int: 04 Wil: 04 Min: 04 Occupation: Conquerors
Inf: 02 Aur: 02 Spi: 03 Resources {or Wealth}: 010
Init: 010 HP: 010

Analytical Smell and Taste/Tracking Scent: 08, Extra Limb (Arm): 05, Growth: 02

Bonuses and Limitations:

  • Analytical Smell and Taste/Tracking Scent is Limited to Analytical Smell Only (-2FC).
  • Analytical Smell does not detect alcohol (-1FC).
  • Growth is always on and already factored in (-1FC).

Vehicles (Land, Sea, Space)*: 04 and either Gadgetry, Medicine (incld Brainwashing), and/or Scientist: 06, depending on the particular Master’s area of expertise.

The Masters lack the Air Subskill of Vehicles because they curiously avoid air travel to the point of lacking any aircraft whatsoever among their equipment on Earth. Accordingly, any use of such craft would effectively be Unskilled. It is unknown how the Masters achieved transport from space to planet surfaces and vice versa.

Genius (only in comparison to 20th Century Earth — none of the Masters demonstrated this Advantage in terms of their own advanced technology), Language (local Earth languages and their own native speech), Rich Friend (while the individual Masters only had the equivalent of the Wealth listed above, the expedition as a whole had at least 26 APs of Wealth, possibly more).

Other Masters (Low).

Altered Anatomy (Only compared to humans), MPR (“Curse of Skloodzi”, also need to drink 4-6 times as much water as humans), Miscellaneous (Alcohol Poisoning), Partial Attack Vulnerability (Soft Spot, -4CS to RV, requires a +2CS Trick Shot to hit), Slowed Aging (lifespan on the order of centuries at least), SPR (require special atmosphere to breathe — see Powers and Abilities section for details), Strange Appearance (this does not affect the Capped, who are conditioned to accept the Tripods and Masters unconditionally).


  • Caps [BODY 01, Radio Communication: 13, Bonus: Radio Comm is Scrambled (+1FC); Limitation: Radio Communication can only receive the Master’s control signal (-1FC)]. A cap can be neutralised with basic tools and a Gadgetry Check against an OV/RV of 02/02).
  • TRIPODS [DEX 03, STR 18, BODY 12, Flash: 02, Extra Limb (Tentacle): 18, Growth: 09, Radio Communication: 15, Sleep: 13, Stretching: 04, Limitations: Growth is Always On and Already Factored In (-1FC); Sleep uses the higher of the Tripod’s DEX or pilot’s Vehicles Skill as AV and the target’s DEX as OV (-2FC total); Stretching only applies to the Tripod’s manipulative tentacles (-1FC)].

Curse of Skloodzi

This odd ague periodically overtakes most Masters, though it more frequently affects the Masters with the darkest skin colors. Treat this as an R# 03 rolled once per week. If the Master fails this rolls he will suffer a +1CS to the OV/RV of all checks made for the next two to three days and his Initiative will be reduced by 4.

Nothing can be done to alleviate the symptoms of or hasten the recovery from this illness, but most Masters will nevertheless stay in their personal quarters and relax by soaking in their garden pools and imbibing large quantities from their soporific gas bubbles.

Masters suffering the Curse of Skloodzi tend to be much more temperamental than usual. Even Masters who did not normally abuse their slaves would sometimes beat them in frustration while ailing. In and of itself, this may be nothing more than a MIA to losing their temper, but Master who already had an IH or Rage would likely find that Drawback raised one level until the Curse went into submission.

The Masters are Cheap Dates

The Masters are especially vulnerable to alcohol poisoning; a tumbler of liquor is sufficient to render a Master unconscious for six hours and inebriated for another 18. Treat ingestion of alcohol as Poison Touch: 12.

Once a Master falls unconscious, he will not awaken for six hours (13 APs of time) and even when he does regain consciousness he will suffer a +3CS to the OV/RV of all actions using an Acting Attribute, with the penalty lessening by 1CS for each six hours after that.

The Will of the Masters

The Masters’ control signal can be represented by use of the Hypnotism Power, usually beaming a single command to worship and obey the Tripods without question. Occasionally, other general commands can be issued, such as bidding the subjects to congregate at certain places. There is no sign that distinct orders can be issued to specific individuals via the television signals or the Caps.

The embedded television signal might only be 1 AP of Hypnotism, attacking on a daily basis until getting a high roll and scoring many RAPs; alternatively, it might be 3 to 4 APs of Hypnotism with a Limitation that it takes long term exposure before it can take effect. The signal received through the Caps is much stronger, probably at least 8-10 APs, and takes effect the moment the Cap is placed on a person’s head.

Design notes

While the Masters do have an extra leg, it is not a manipulative appendage and doesn’t even provide redundancy (a Master whose third leg was rendered useless would likely suffer the same limitations to mobility that a human with one unusable leg would), so I did not add Extra Limb for the Leg.

Tripods have had Extra Limb added for the third tentacle (which was not demonstrated but extremely likely given the Masters’ psychology and engineering) and Running was eliminated since Growth already provides the necessary speed increase.

Indeed, I bumped the DEX down 1 AP with that in mind, though it’s still in the same column and the pilot’s can use their own DEX and/or Vehicles Skill for purposes other than movement anyway.

While the Curse of Skloodzi does make the Masters more volatile, I don’t think it went to the level of an IH or Rage in and of itself. I have added notes regarding the issue.

By Roy Cowan.

Source of Character: The Tripods Quadrology by John Christopher — When the Tripods Came, The White Mountains, The City of Gold and Lead, The Pool of Fire (novel series).

Helper(s): Eric Langendorff, hominid71.