The Mega Dungeon Campaign Worlds Of Arthur C.Clarke's Rendezvous with Rama

Published in 1972 four years after 2001 A Space Odyssey, Rama stands on its own in the annals of science fiction.
Wiki summarizes the plot thus :
Set in the 22nd century, the story involves a 50-kilometre (31 mi) cylindrical alien starship that enters Earth's solar system. The story is told from the point of view of a group of human explorers, who intercept the ship in an attempt to unlock its mysteries.
Rama is more then just simply an artifact flying through space. Rama is an enema wrapped in a mystery waiting for someone to  unlock it. 
The artifact is massive & the book deals with science fiction on a different scale compared to many other science fiction novels of the time. The scale is actually on the 2001 a Space Odyssey scale. Characterized by overwhelmingly alien concepts, unexplained & unseen aliens, & an artifact that continues to function despite humanity's intrusion.
Major plot spoilers ahead! 
Wiki summerizes the whole book but really doesn't do it justice. This is a must read it to get into the head of the author style of science fiction book. Its readily available in many used book stores.
The plot & stories goes as thus: 

After a major disaster caused by a meteorite falling in Eastern Italy in 2077, the government of Earth sets up the Spaceguard system as an early warning of arrivals from deep space.

The "Rama" of the title is an alien star ship, initially mistaken for an asteroid categorised as "31/439". It is detected by astronomers in the year 2130 while still outside the orbit ofJupiter. The object's speed (100 000 km/h) and the angle of its trajectory clearly indicate that this is not an object on a long orbit around our sun; it comes from interstellar space. Astronomers' interest is further piqued when they realise that this asteroid not only has an extremely rapid rotation period of 4 minutes, but it is exceptionally large. It is subsequently renamed Rama after the Hindu god and an unmanned space probe dubbed Sita is launched from the Mars moon Phobos to intercept and photograph the object. The resulting images taken during its rapid flyby reveal that Rama is a perfect cylinder, 20 kilometres (12 mi) in diameter and 54 kilometres (34 mi) long, made of a completely featureless material, making this humankind's first encounter with an alien space ship.

The manned solar survey vessel Endeavour is sent to study Rama, as it is the only ship close enough to do so in the brief period Rama will spend in our solar system. Endeavour manages to rendezvous with Rama one month after the space ship first comes to Earth's attention, when the giant alien spacecraft is already within Venus' orbit. The 20+ crew, led by Commander Bill Norton, enters Rama through triple airlocks, and explores the vast 16-km wide by 50-km long cylindrical world of its interior, but the nature and purpose of the starship and its creators remains enigmatic throughout the book. Inside Rama, the air is discovered to be breathable. The astronauts discover several features, including "cities" (odd blocky shapes that look like buildings, and streets with shallow trenches in them, looking like trolley car tracks) that actually served as factories, a sea that stretches in a band around Rama dubbed the Cylindrical Sea, and seven massive cones at the southern end of Rama - believed to form part of the propulsion system.

One of the crew members, Jimmy Pak, who has experience with low gravity skybikes, volunteers to ride a smuggled skybike along Rama's axis to the far end, otherwise inaccessible due to the cylindrical sea and the 500-m high cliff on the opposite shore. A few hours later, Jimmy reaches the massive metal cones on the southern end of Rama, picking up a strange magnetic field coming from the cones. Pak takes a few pictures of the area and the strange plateau on the southern end of Rama's landmass before leaving. The electrical charge in the atmosphere begins to increase during Pak's return, resulting in lightning. A discharge hits his skybike causing him to crash on the isolated southern continent.

When Pak wakes up, he sees a crab-like creature picking up his skybike and chopping it into pieces. He cannot decide whether it is a robot or a biological alien, and keeps his distance while contacting Norton and the others on the other side of Rama for help. Norton sends a rescue party across the cylindrical sea, using a small, improvised craft, and Pak waits. He sees the crab-like creature dump the remains of the skybike into the sea, and he approaches the creature, but it completely ignores him. Pak explores the surrounding fields while waiting for the rescue party to arrive on the southern cliffs of the cylindrical sea. Amongst the strange geometric patterns he sees an alien flower growing through a cracked tile in the otherwise sterile environment, and decides to take it as both a curiosity and for scientific research.

Pak jumps off the 500m cliff, his descent slowed by low gravity and using his shirt as a parachute, and swims quickly to the craft. The ride back is highlighted by tidal waves in the cylindrical sea, formed by movements of Rama itself as it makes course corrections. When the crew arrive at base, they see a variety of odd creatures inspecting their camp. When one is found damaged and apparently lifeless, the team's doctor/biologist Surgeon-Commander Laura Ernst inspects it and names it a "biot" or a hybrid of a biological entity and robot. She concludes that it, and others, appear to be electrically powered by natural internal batteries (much like terrestrial electric eels) and possess some degree of intelligence. They are believed to be the servants of Rama's still-absent builders and maintainers of the starship.

The members of the Rama Committee and the United Planets, both based on the moon, have been monitoring events inside Rama and giving feedback. The Hermian colonists have concluded that Rama is a potential threat to them and send a rocket-mounted bomb to destroy Rama. It is successfully defused by Lt Boris Rodrigo using a pair of wire cutters.

As Rama approaches perihelion, the biots act strangely - jumping into the cylindrical sea where they are destroyed by aquatic biots ('sharks'), and absorbed back into the mineral-laden water. On one last expedition to explore Rama, a few crew members decide to visit the city "London" (chosen as closest to the stairways at the "northern" end of the cylinder they use to return to their ship) to use a laser to cut open one of the buildings and see what is inside. Inside, they discover pedestals containing holograms of various artifacts, believed to have been used by the Ramans as tools and other objects. The holograms themselves are presumed to be templates for replicating these items as needed. The most amazing sight is what appears to be a uniform with bandoliers, straps and pockets that suggests the size and shape of the Ramans. But before the crew can photograph any more holograms, the lights start going out, and they must leave. They all exit up through the stairway on Rama's northern side, out of the three airlocks, and board Endeavour.

When Endeavour is a safe distance away, and Rama reaches perihelion, Rama harnesses the Sun's gravitational field with its mysterious "space drive" for use in a slingshot manoeuvre and is flung out of the solar system toward an unknown location in the direction of the Large Magellanic Cloud.

The book was meant to stand alone, although the final sentence of the book suggests otherwise:

And on far-off Earth, Dr. Carlisle Perera had as yet told no one how he had wakened from a restless sleep with the message from his subconscious still echoing in his brain: The Ramans do everything in threes.

Clarke, however, denied that this sentence was meant to hint at a continuation of the story-–according to his foreword in the book's sequel, it was just a good way to end the book and was added during a final revision.

 A Note About Project Star Guard
 
 The concept of the 1972 version of Rama that differs from the sequals & many other things written within the Ramaverse is the tone. Project Star Guard is the perfect organization for a DM who wants to use an organization of dedicated professionals without the science fiction BS .  According to Wiki:
Clarke invented the space study program which detects Rama, Project Spaceguard, as a method of identifying near-Earth objects on Earth-impact trajectories; it was initiated after an equally fictional asteroid "struck" Italy on September 11, 2077, destroying Padua and Verona and sinking Venice.The manned solar survey vessel Endeavour is sent to study Rama, as it is the only ship close enough to do so in the brief period Rama will spend in our solar system. Endeavour manages to rendezvous with Rama one month after the space ship first comes to Earth's attention, when the giant alien spacecraft is already within Venus' orbit. The 20+ crew, led by Commander Bill Norton, enters Rama through triple airlocks, and explores the vast 16-km wide by 50-km long cylindrical world of its interior, but the nature and purpose of the starship and its creators remains enigmatic throughout the book
 The party is professional, cool, & gets the job of  exploring Rama done. They almost don't make it home with their lives. For a DM whose run this:

The Ramaverse is the way to go. The Star Guard & the Endeavour  are perfect fodder. 

Rama's Secrets Revealed!
Major Spoilage 

Rama simply put is a major space going mega dungeon that makes the Warden look like Sunny brook farm! Seriously the sheer scale makes the head boggle! Here's the stats according to Wiki :

The interior of Rama is essentially a large cylindrical landscape, dubbed 'The Central Plain' by the crew, 16 kilometres wide and 50 long, with artificial gravity provided by its 0.25 rpm spin. It is split into the 'northern' and 'southern' hemispheres, divided in the middle by a 10-km wide expanse of water the astronauts dub the 'Cylindrical Sea'. In the center of the Cylindrical Sea is an island of unknown purpose covered in tall, skyscraper-like structures, which the astronauts name 'New York' due to an imagined similarity to Manhattan. At each end of the ship are North and South "Poles". The North Pole is effectively the bow and the South Pole the stern, as Rama accelerates in the direction of the north pole and its drive system is at the South Pole.

The North Pole contains Rama's airlocks, and is where the Endeavour lands. The airlocks open into the hub of the massive bowl shaped cap at the North Pole, with three massive 8-kilometre long stair systems, dubbed Alpha, Beta, and Gamma by the crew, leading to the plain. The Northern hemisphere contains several small 'towns' interconnected by roads, dubbed London, Paris, Peking, Tokyo, Rome, and Moscow. The South Pole has a giant cone-shaped protrusion, surrounded by six smaller ones, which are probably a major part of Rama's reactionless "space drive".

Both ends of Rama are lit by six giant trenches (three in the northern hemisphere and three in the south), equidistantly placed around the cylinder, effectively functioning as giant strip lighting.

The real star of the book isn't the crew & their escapades the real star is Rama & its artifacts. Even the critics have noticed this because in the squeals with their big reveals it just not the same. According to Wiki : "Clarke paired up with Gentry Lee for the remainder of the series. Lee did the actual writing, while Clarke read and made editing suggestions.^[6] The focus and style of the last three novels are quite different from those of the original with an increased emphasis oncharacterization and more clearly portrayed heroes and villains, rather than Clarke's dedicated professionals." Wiki actually has the best break down of Rama : 

"In the story, Rama is first encountered by humans in the year 2131, when it enters the solar system at a speed and heading that will take it on a 'slingshot' course around the sun and back out into deep space. It is initially mistaken for a giant asteroid when first detected by SPACEGUARD, an automated radar net designed to warn Earth of potential impact threats. Its first designation is therefore a database code: "31/439", according to the year (2131 CE) and its order of discovery. As it travels closer to perihelion, it comes to the attention of humans due to its anomalous shape and heading. Still believing it to be an asteroid, astronomers give 31/439 a proper name due to its size. Following the tradition of naming celestial objects after mythological figures, 31/439 becomes "Rama", after the Hindu deity; Clark explains that by this time, all the names of Greek and Roman mythological figures have been used up.

A 3D artist's impression of the interior of Rama.

After much speculation over the following months, telescope observation and unmanned probes confirm that Rama is an artificial construct, and therefore (albeit indirectly) Earth'sfirst contact with extraterrestrial life. The Rama vessel is intercepted and explored by the crew of the nearest human space vessel, the Solar Survey ship Endeavour, under Commander William Norton. Endeavour intercepts Rama, Norton and his team explore the ship, and depart after a three-week mission. Rama, apparently indifferent to the life forms it has encountered, refuels using the matter and energy collected from the sun, executes several minor course corrections, and leaves the solar system." 

Stats which I'm leaving System neutral :

Statistics

	Exterior/Overall	Interior
Length	~54 km	~50 km
Diameter	~20 km	~16 km
Surface Area	~4000 km2	~2500 km2
Volume	~17000 km3	~10000 km3
Mass	~1016 kg

(The distances are approximate, since they appear to vary throughout the book.)

• Propulsion. Rama's maximum acceleration is 0.02 g, or 0.1962 m/s² when the Cylindrical Sea is liquid, and when it is frozen, in excess of 10g, or 100 m/s², such as to attain relativistic speeds quickly, using an unknown form of reactionless drive, which seems to operate by generating a field around Rama that negates the inertia of the mass that it captures. Nearby vessels are deflected when it operates. Whatever the nature of its engineering, Rama could freely control its velocity, rotation and heading.
• Power. Rama can refuel by absorbing energy and material en masse directly from a star. When traveling between stars without voyagers, virtually all of its systems and mechanics are shut down, and it effectively becomes a dead relic; its temperature reaches nearly absolute zero. If it has voyagers aboard, it keeps Rama's interior above the melting point of the Cylindrical Sea. Whether it can merely store energy or generate it, most likely via nuclear fusion like the suns it siphons, is unknown. The most likely source of both Rama's power and propulsion seems to be the Horns.
• Defense. Passive. Rama's hull, except around the Cylindrical Sea and the North Pole (see below), is at least 2 km thick, and composed of an unidentified alloy that could withstand direct radiation from Sol up to a radius of 5 million km. Rama I's hull is completely solid according to seismic tests; Rama II's hull is crisscrossed with a maze of tunnels, rooms, and halls. Rama could also create a bubble of perfectly reflective material around itself, in which it passed through the sun's chromosphere unharmed. Also, a mesh-like type of "cocoon", when deployed around Rama, is able to negate the effect of nuclear weapons which were fired at it in Rama II
• Offense. Rama has displayed no hostile capability of any kind, although its size makes it a defensive threat.

[edit]Design

Most of the following names and terms were chosen arbitrarily by the crew of the Endeavour.

The fore end of Rama's axis, in the direction of its acceleration, is called North. The aft end is South. These points make up the navigational system used inside Rama.

• North Pole: The bow of Rama is designed around three airlocks.
• South Pole: The stern of Rama is where the engines are located.
• The Cylindrical Sea: An artificial body of water that divides Rama's internal space between northern and southern hemicylinders.
• New York: A mysterious clustering of tall buildings on an island in the middle of the Cylindrical Sea.
• The Horns: A regular grouping of spires at the South Pole, within Rama. Exactly at the Pole is a single large spire dubbed the "Big Horn", and arranged in a hexagonal pattern around this are six other spires (aka "Little Horns"), each shorter and with a smaller diameter. The Horns seem to be used in Rama's enigmatic system of propulsion.
  
   Rama In The OSR 
  
  
  Confession time for over 30 plus years Rama has been my go to mega space dungeon. I first used some of its concepts with the Warden when I ran a game of Metamorphosis Alpha. The Events of first edition Gamma World's time line propelled me to grab my copy of Rama & use one of these craft. 
  The Raman's craft are the perfect big dumb object. They're self sustaining & can be found just about anywhere. 
  These space craft are perfect for using a game like Terminal Space. The dungeon is out there in the great unknown & the party finds it. The mysterious powers or aliens remain mysterious & they find a few alien object to show to the folks back home. 
  Carcosa is whole different matter. Rama could be used as a blue print for powers beyond mankind in a indifferent universe. Here the Raman's might be Elder Gods or powers man wasn't meant to know. Rama could well be a stock pile of an alien biosphere waiting for its cycle to activate. Turn up the Lovecraft & down the Clarke.
  Mutant Future  or even Mutant Epoch as a campaign could take place entirely within the confines of a Rama craft. The thing might be breaking down & need assistance of its alien masters. Even then questions might not be answered at all.
  Rama is blueprint for Stars Without Number. Seriously all you need to do roll characters up & go.
   For a Super Hero game Rama is a creditible threat that can be so much more. The entire campaign can be moved with the confines of one of these ships for a truly cosmic journey.  Marvel Super Heroes is tailor made for the scale of this book.
  I have to say though go find Rama & read it before attempting to use it. This blog entry is in no way an attempt to infringe on the copy right holders or the memory of Arthur C. Clarke
  For even more information see the wiki entries :
  Rendezvous_with_Rama
  Rama_(spacecraft)