Designer's Notes: GURPS Mars

by James L. Cambias

Let me begin with a dreadful confession. The whole reason I proposed and wrote GURPS Mars was simply to have an excuse for learning a lot about Mars, space travel, terraforming, and pulp science fiction. Happily, Steve Jackson and his loyal minions were kind and gullible enough to let me do it, even going so far as to pay me.

When a book attempts to cover an entire planet, over thousands of years of history plus a couple of alternate universes thrown in for good measure, things get left out. In particular, there was no room for a sample adventure. What follows is an attempt to remedy that lack. It's not quite an out-take, because it was never in to begin with.

The Secret of the Labyrinth: An Adventure for GURPS Mars

This adventure can be used in any of the four GURPS Mars campaign settings (with some minor adjustments).

Superscience Martian Transport Walker

This is a low, six-legged vehicle used for transport on the Martian surface. It could also be used as a scout vehicle and armored personnel carrier in an invasion of Earth. Because of its six legs, the transport walker is fairly easy to drive, even for Earthlings unfamiliar with walking machinery.

Subassemblies: Body +3, 6 Legs [U:Body] +2.
Powertrain: 200-kW RTG with 150-kW leg drivetrain.
Fuel: --
Occupancy: 2 NCS, 6 NS.Cargo: 3cf, 150 lbs.






















Body: 1,000-mile radio, Low-light TV (+3), GPS, Winch (ST 50), TL9 radiation shielding, 16 Martian-days limited life support.


Size: 6' 10'Payload: 1,750 lbs.Lwt.: 4.5 tons (Earth), 1.75 tons (Mars).
Volume: 420 cf.Maint.: 59 hours.Price: $145,000.
HT: 12.
HP: 450 Legs: 75 each.

gSpeed: 65gAccel: 20gDecel: 20gMR: 0.75gSR: 4
Extremely Low GP; off-road speed 65 mph.

The Mission

The player-characters are explorers venturing into the Noctis Labyrinthus region of Mars. Exactly who they are and why they are going there depends on the setting. On Domed Mars they are astronauts on an early Mars expedition, making the first survey of the area. On Terraformed Mars they are MDF troopers investigating anomalous reports from the orbital sensor web -- possibly signs of Red Mars guerrilla activity. On Superscience Mars the explorers are elite Martian battlesuit troopers sent by the Science Lords on a routine sweep for mutants and outcasts. And on Dying Mars they are a party of Science Priests and companions venturing into the Labyrinthus area in search of ancient artifacts.

The expedition is a small party, consisting only of the heroes and their equipment. A Domed Mars group gets one or two nuclear-powered pressurized rovers, as described in the book. Terraformed Mars characters take a TL9 improved rover, with perhaps an inflatable pressure tent for camping out. The Superscience Mars troopers get a Transport Walker (see the sidebar). Dying Mars characters can travel on riding-lizards, on foot, or by wagon.

Other gear is up to the party. Note that on Domed Mars there are no weapons as such. On Terraformed Mars the team will not be able to get anything heavier than their standard-issue Gyroc carbines. The Superscience troopers have their official Shock Trooper battlesuits, ray-pistols (electrolasers) and portable heat-beams (military laser rifles). Dying Mars Science Priests and their entourage have whatever weapons they wish -- the Labyrinth is known to be a haunt of bandits.

The Labyrinth

Noctis Labyrinthus is a weird and dangerous region on any version of Mars. Long ago some titanic force pushed up the crust here, cracking and splitting the surface into a network of chasms and rifts. Heat (presumably from the magma plume below) melted some of the ice in the crust, and flowing water excavated the fault lines and drained off into Marineris Valles.

The result is an area the size of Montana, consisting of isolated plateaux and mesas, criscrossed by canyons. The canyons are as much as 3 miles wide and sometimes more than a mile deep. Melting water has also formed caves beneath the plateaux, opening into the canyons.

In three versions of Mars from GURPS Mars, the Labyrinth is almost uninhabitable. Its great altitude (4 miles above mean datum) makes the air too thin to breathe even in the later stages of terraforming. The Martians of Superscience Mars and the humans of Terraformed Mars can survive the Labyrinth with respirator masks, as described in GURPS Space and Ultra-Tech.

On Dying Mars the air of the Labyrinth is thin, but breathable. Martians of that world need only make a HT roll when attempting something strenuous (like hand-to-hand fighting, for example). A failed HT roll costs 1 point of Fatigue.

Naturally, humans on Domed Mars need Mars suits to survive outdoors in the Labyrinth, just as they do elsewhere on the planet. There is an increased radiation risk due to lack of protecting atmosphere.

The confusing multitude of branching chasms and valleys in the Labyrinth make navigation difficult, even with accurate maps. Navigation skill is at a -3 penalty, -1 if the travelers have a GPS or other high-tech navigation aid.

The broken terrain of the Labyrinth also makes it a good place for ambushes and surprise attacks. In almost any setting the hostile conditions and good concealment make the Labyrinth a natural refuge for rebels and bandits.

Explorer Robot

This is a TL8 robot used for surface exploration by Mars expeditions. It can operate on its own for long periods, navigating across the surface with the help of satellite locators and an internal map of the planet. Its neural-net computer lets it learn from experience and adapt to unusual situations. A human controller can remote-operate it in realtime, or simply assign it tasks. The robot is not armed, but it can make melee attacks with its sampler arm, which has a sharp shovel blade.

The robot has ST 8/20, DX 10, IQ 8, HT 11. Its Move is 7.

It has night vision, imaging Ladar, an inertial compass, a radiation detector, a chemscanner (touch only), and a single arm capable of doing 1d+3 cutting damage in melee. The robot is radiation hardened (PF 10) and is covered with armor (PD 3, DR 10).

The robot has only one eye, no sense of hearing or smell, and only one arm with Bad Grip. It is mute. Total weight is 200 lbs (Earth) or 76 lbs (Mars); size is 3.8 cubic feet.

Brain: TL8 standard, compact, genius, hardened, neural net (60 lbs, 1.2 cf, $300,000, Complexity 4, IQ 8); 70 points.
Sensors: basic TL8 package with Night Vision, one eye, deafness, no sense of smell/taste, imaging LADAR, radiation detector, and chemscanner (5 lbs., 0.1cf, $7,700); 25 points.
Communicators: basic TL8 package with Mute, long-range radio, and lasercom (19.2 lbs, 0.4 cf, $5,700); 7 points.
Arm Motors: one ST 20 extendible arm with Bad Grip (8 lbs., 0.16cf, $8000); -15 points.
Propulsion: 200-watt wheeled drivetrain (1.5 lbs, 0.03cf, $30).
Weapons: Sharp Claw shovel blade ($200).
Navigation Systems: Inertial compass (1 lb., 0.02cf, $250); 5 points.
Cargo Space: 1 cubic foot.
Power: 10 square feet of solar cells generating 0.2 kW on Mars (1 lb., $300); rechargeable C cell storing 1800 kws (1 lb., 0.01cf, $100). 10 points.
Subassemblies: Solar Panel 10 sf; Arm 0.2 cf, 2.5 sf; Wheels 0.6 cf (0.1cf each), 1.5 sf each; Body 3cf, 13 sf.
Structure: Solar panel is expensive extra-light (7.5 lbs., $500), Arm is expensive light (3.75 lbs., $250), body is expensive light (19.5 lbs., $1300), wheels are expensive medium (27 lbs., $1800). Total: 51 lbs.
Hit Points: Solar panel 4, Arm 4, Body 10, Wheels 4 each.
Surface Features: body has DR 10 ablative (3.9 lbs., $31); arm has DR5 ablative (0.375 lbs, $3), wheels have DR10 nonrigid (3.6 lbs., $360). Body and arm are sealed ($620). Body has radiation shielding (26 lbs., $260). 64 points.
Design Weight: 185 lbs., .0925 tons on Earth; 71 lbs, .0352 tons on Mars. Loaded weight 200/0.1 on Earth, 76/.038 on Mars.
Total volume: 3.8 cf.
Price: $327,404
ST: 8/20 [45 points]DX 10IQ 8 [-15]HT 11 [5]
Ground Speed: 11 (7 off-road).

The Monster of the Labyrinth

The Labyrinth is a mysterious, timeless place. Even in the Terraformed Mars setting, it is barely affected by the planet's transformation. Gamemasters can use it as the Martian "Bermuda Triangle" -- a place where reality is thin, and things can fall into different worlds.

The Monster of the Labyrinth is one such interloper -- or perhaps the heroes have blundered into another world themselves. On the three high-tech versions the first sign of something strange is that the air outside is thicker and contains more oxygen. Dying Martians will notice that there are no plants visible and the temperature has gotten very chilly. Then the Monster appears.

In Domed Mars the Monster is a Dying Martian nomad war-band, riding lizards and armed with spears and a few muskets. The warriors have seen (or heard of) motor vehicles, so they won't be awestruck or fearful of the crawlers. They will attack aggressively, leaping from their lizards onto the moving crawlers and trying to break in.

In Terraformed Mars the menace is a war tripod from Superscience Mars. Its pilot will attack aliens on sight, going after their vehicle first and then trying to mop up stragglers.

In Superscience Mars the enemy is a party of Red Mars guerrillas armed with stolen TL9 military hardware from the Mars Defense Force. The Red Mars people have Gyroc carbines (see GURPS Ultra-Tech), with both SLAP and APEX ammunition, and a dozen carefully-hoarded Viper rounds with smart guidance. They also have two 120-mm single-shot rocket launchers (see Ultra-Tech 2). The Reds are wearing civilian skinsuits (PD 0, DR 1) with respirator masks; two of them have TL9 ablative torso armor to wear over their suits (PD 4, DR 24 vs. energy weapons, PD 1, DR 4 against projectiles). They will initially be curious about this strange vehicle and its stranger crew, but if hostilities begin the Reds will fight very intelligently, using cover, trying to take out the vehicle with their heavy weapons, and then picking off the infantry one by one.

In Dying Mars the foe is a NASA robot probe, cut off from outside control and unable to recognize the heroes as intelligent beings. See the sidebar for stats. The robot can tell that the Martians are living creatures because they move and are warmer than the surrounding environment. Its designers did program it to recognize humans, but nobody expected it to meet intelligent Martians. Upon detecting life it will immediately try to get samples and stuff them into its storage space.


After the initial combat, the party meets another explorer, from a different world, who has found the source of the problem but can't solve it alone. The other is from a different world again. If the party are Domed Mars explorers, they encounter Nelidor, one of the Science Lords of Superscience Mars, out investigating unusual phenomena. If they are from Terraformed Mars, they meet Sistreen, a Science Priest from Dying Mars. Superscience Martians meet Dana Barry, a NASA scientist from Domed Mars. Dying Martians encounter Robin Kim, a Carter-series genemod field ecologist from Terraformed Mars. In each case, the new arrival is not armed, and is considerably shaken up by an encounter with hostiles. Their motives are different, however: Nelidor will try to turn any situation to his advantage, Sistreen is obsessed with recovering valuable technology, Ms. Barry is helpful and curious about everything, and Ms. Kim suspects the whole thing may be some sort of weird media stunt.

Each of the researchers has made the same discovery. The center of all the weird happenings in Noctis Labyrinthus is right at the highest altitude point, at longitude 102 by latitude -7. As the party travels to the site they encounter traces of other travelers from a variety of alternate versions of Mars -- steampunk Victorian Mars explorers, 1950s Von Braun expedition astronauts, a Rust China military squad from Transhuman Space, or whatever other worlds the GM prefers.

At the center of the weird phenomena there is a strange five-sided pyramid of crystal, about ten meters tall. The sinister tentacled Martians glimpsed in visions by H.G. Wells and others are conducting a magical ritual there, trying to restore life to their own Mars by draining it from dozens of parallel worlds. The PCs can actually see and feel the life energy (mana, orgone, whatever) being sucked toward the pyramid.

There are twice as many tentacled Martians as player characters; fortunately they have no Heat-Rays or war machines handy, but their own vitality has been boosted by the pyramid. They will try to take the PCs alive if possible (no sense wasting all that nice fresh blood), but will kill to protect the pyramid.

The pyramid is fragile. Any single attack doing more than 10 points of damage will crack it, releasing the stolen energy in a dazzling flash. Without the pyramid as a focus for the magic, the connection among the worlds collapses, catapulting everyone back to their proper settings.

Villainous Tentacled Martians

The Tentacled Martians are horrid creatures, the end product of a million years of evolution and genetic engineering aimed at creating pure intellects. They are big boneless leathery creatures, roughly the size of a bear, with two bunches of tentacles, huge staring eyes, and a slack lipless mouth. On Mars they can get around fairly well walking on their tentacle bunches, but are helpless on worlds with higher gravity (the statistics here are for their native environment).

Tentacled Martians have ST 6 [-30], DX 8/12 [-20], IQ 14 [45], HT 10, and Move 4. They have the racial advantages Acute Hearing +2 [4], Extra Arms (6) [60], Manual Dexterity (+4) [12], Night Vision [10], Telepathy-3 [15], and Thick Hide (PD1, DR1) [28]. Their racial disadvantages are Callous [-6], Dying Race [-10], Odious Personal Habit (preys on humans) [-20], and Weak Immune System [-30]. Skills for this party include Brawling-8, Knife-12, Mental Blow-12, Mind Shield-14, Stealth-10, Telereceive-14, Telesend-14, Weird Science-14, and Weird Magic-14.

These Martians don't have any of their super-scientific weapons, but they are equipped with scalpel-sharp knives doing 1d-3 impaling damage, and their own psionic powers.

Article publication date: July 19, 2002

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