Arborcrawling in the 27th Century

In which a setting frequently referred to as 'Space Hulk in a Tree' is taken back into space.

It is the 27th Century. Everything is in space and everything is very exciting.

On the fringes of humanity's stars lies the Cardigan system, home to five gas giants. Orbiting one of these is the moon of New Llanabba. This is a 'hollow moon', home to a thousand tunnels and extensive cave networks. The intense and rather unpredictable gravity field of Cardigan-3 has drawn into countless asteroids and assorted space junk into New Llanabba, making it a haven for prospectors. A great crater in the surface of the moon called 'Abba's Maw' gives access to the tunnels.

Orbiting New Llanabba is a space staton run by an eclectic ecological group called The Five Mothers. In order to pay for bulbs, fertiliser, seed cuttings, trowels, &c, they allow prospectors and other opportunists the a place to stay in return for a cut of their findings. However, numerous hostile aliens and space bandits lurk in the hollow moon - aside from more natural perils. 

Exploring New Llanabba: Really, you should use Veins of the Earth here. For a quick and silly alternative:

Roll 1d6. That is the number of passages into the cave. 

Roll 1d8. 1=N, 2=NE, &c. That is roughly where the passage enters the cave. 

Roll 1d10. If you get a 9, there is a hole in the floor of the cave. If get a 0, there is a hole in the celling of the cave.

Pick a county at random. That is the shape of the cave.

Perils of New Llanabba: It is very easy for an explorer to run out of oxygen, fusion generators, food pills, &c. And the caverns of the hollow moon are filled with chasms, rubble, unexpected drops, shifting debris, pockets of flammable gas, &c. But you want to know if there is anything you can fight. There is.

Insectoid Horrors: mindless beasts that skitter and whoop. Want to eat you.

Termite Men: organised bands of hostile aliens, who fight with crystalline spears, mucus grenades and packs of giant centipedes. Want you to kill you and take your stuff.

Rock Lobsters: ponderous stone-covered beasts with great pincers. They can spit bio-plasma. Cutting them open reveals them to be filled with tiny glowing shrimp. Want you to go away and stop disturbing their meditations. 

Giant Moths: Attracted to light, hypnotic pattern on their wings. Want to steal your power cells. 

Stranded Precursor: Member of a long-dead ancient species. Confused, powerful, distressed. Want to return home: if this turns out to be impossible, they want to attain dominion over the younger sentients of the galaxy.

Robotic repairman: Looks like a hermit crab made of Meccano. Want to repair something that once crashed in the cave. Willing to use your remains to do so.

Space Amazons: Stronger than you, better hair than you, not terribly interested by you. Wear highly customised spacesuits. Carry beam rifles, heat-seeking slug-guns, attack drones like carbon-fibre falcons and kukris. Interested in opportunities for glory and plunder.

Rival Explorers: Just like you, except they have at least one prominent unattractive trait. You are proud and confident free-spirited mavericks, they are smug, cocky, self-centred renegades. Want what you want. 

One prospecting group has recently made great progress in exploring the hollow moon. These include...

Orsino, Prince of Illyria. Apparently the heir to an entire planet. Looks like a young Shakespearean actor, doesn't always sound like it. Improbably dashing. Equipment: monomolecular sabre, Art Nouveau hunting rifle, dress uniform that makes him look like the pilot of one of the Thunderbirds.

Elrich Kilpatrick. Recipient of a mysterious vision at the galaxy's edge. Now leads a spiritual movement centred on a cosmic power called 'The Destiny'. Quite what this is is unknown, but apparently it means that Kilpatrick must wear a jet-black spacesuit and spend hours on the observation deck staring into space. He is accompanied by his followers, dressed in brightly coloured cheap spacesuits. Equipment: Ornate plasma fusil, energised broadsword, Babel-76 translation circlet.

The Rinians. No taller than a thirteen year-old, skin periwinkle-coloured, there are never less than four of them. They are a hivemind, choosing personal names almost at random from nearby literature. Their origin is unknown, but apparently they have some connection with the second world of the Searle system. Equipment: Aside from the small arms available on New Llanaba, they have an apparently never-ending supply of switchblades, Molotov cocktails and marbles.

Agamemnon. A product of Corinth Cybernetics, an android counsellor and confidante. Stylised bronze plating and chassis, with a detailed unmoving bearded face. Despite being sexless, a previous employer programmed Agamemnon with the mannerisms and social presence of Rudolf Valantino.* Equipment: Sophisticated mapping gear and sensor array, Web grenades, Three Fire-and-forget suicide drones, One-shot Inferno Projector, Tiny laser-derringer for when everything else runs out or breaks.

Gower Macmorris. The Merakians are tall, broad and six limbed. They are covered in thick black fur with distinctive off-white stripes. Each limb has a number of thick claws, quite capable of rending a man in twain. Gower was, for a time, the foremost cat-burglar in the Merak system. He was considered slight and lithe. This makes him an absolute unit of the awe-inspiring variety in human space. Equipment: four big claws, assorted Merakian-sized lockpicks and electronic bypasses, ornate studded war-club stolen from a vault somewhere.

The above have recently come into possession of several Hippogriff-class shuttles. These are aged and require much maintenance but extend their reach marvellously over New Llanaba.

*Or some other suitable matinee idol. 

Referring, variously to this and this. Post written in memory of the departed Pandion. 

Image from the 1981 film Time Bandits, Dir. Terry Gillam.