~ Spelljammer for Space Engine ~
Spelljammer is a campaign setting for the Advanced Dungeons & Dragons (2nd edition) role-playing game, which features a fantastic (as opposed to scientific) outer space environment.
Spelljammer introduced into the AD&D universe a comprehensive system of fantasy astrophysics, including the Ptolemaic concept of Crystal Spheres. Crystal Spheres may contain multiple worlds and are navigable using spaceships equipped with "Spelljamming Helms". Ships powered by spelljamming helms are capable of flying into not only the sky but into outer space. With their own fields of gravity and atmosphere, the ships have open decks and tend not to resemble the spaceships of science fiction, but instead look more like galleons, animals, birds, fish or even more wildly fantastic shapes.
The Spelljammer setting is designed to allow the usual sword and sorcery adventures of Dungeons & Dragons to take place within the framework of outer space tropes. Flying ships travel through the vast expanses of interplanetary space, visiting moons and planets and other stellar objects. Though the cosmology is derived largely from the Ptolemaic system of astronomy, many of the ideas owe much to the works of Jules Verne and his contemporaries, and to related games and fiction with a steampunk or planetary romance flavor. A strong Age of Sail flavor is also present.
A crystal sphere (also known as a crystal shell) is a gigantic spherical shell which contains an entire planetary system. Each sphere varies in size but typically they are twice the diameter of the orbit of the planet that is farthest from the sun or planet at the center of the sphere (the system's primary). Due to floating point errors of most CPUs the exact placement of objects far from our sun is difficult in Space Engine, therefore the Crystal Sphere of Realmspace is much larger. The surface of the sphere is called the "sphere wall" and separates the void of "Wildspace" (within the sphere) from the "Phlogiston" (which surrounds and flows outside the sphere). The sphere wall has no gravity and appears to be impossible to damage by any normal or magical means. Openings in the sphere wall called "portals" allow spelljamming ships or Wildspace creatures to pass through and enter or exit from a crystal sphere. Portals can spontaneously open and close anywhere on the sphere wall. Note: Unlike the Ptolemaic system, the crystal spheres are not nested within each other.
Wildspace is similar to the outer space of science fiction, with planets, asteroids and stars, but with different physics. Gravity is either none or the same as that of Earth, and is directed towards the center of planet-sized bodies; on large objects in space like spacecraft and enormous creatures gravity is directed towards a flat plane running through the object's long axis, allowing characters to stand on the decks of ships.
The Phlogiston is essentially a big ocean of a unique element that is neither air, fire, water, or earth. The Phlogiston (also known as "the Flow") is a bright, extremely combustible gas-like medium that exists between the Crystal Spheres. A signature property of the substance is that it does not exist within the boundaries of a crystal sphere, to the degree that it cannot be brought into a crystal sphere by any known means up to and including the direct will of Gods & Deities. Every crystal sphere floats in the Phlogiston, very slowly bobbing up and down over time. Travel between Crystal Spheres is facilitated by the formation of "Flow Rivers" — sections of the Phlogiston which have a current and greatly reduce travel time. Travel through the "Slow Flow" (i.e. off the Flow Rivers) is possible, but very dangerous.
Note: Published sizes for all the planets are completely ludicrous. I have adjusted all sizes as follows:
Size A Less than 10 miles to 750 miles diameter 1,200 kilometers diameter
Size B 10-100 miles across to 1,500 miles diameter 2,400 kilometers diameter
Size C 100-1K miles across to 3,000 miles diameter 4,800 kilometers diameter
Size D 1-4K miles across to 6,000 miles diameter 9,600 kilometers diameter
Size E 4k-10k miles across to 12,000 miles diameter 19,300 kilometers diameter
Size F 10k-40k miles across to 48,000 miles diameter 77,300 kilometers diameter
Size G 40k-100k miles across to 168,000 miles diameter 270,000 kilometers diameter
Size H 100k- 1m miles across to 672,000 miles diameter 1,081,500 kilometers diameter
Size I 1m-10m miles across to 2,688,000 miles diameter 4,326,000 kilometers diameter
Size J 10m across to over 2,688,000 miles diameter 4,326,000 kilometers diameter
The Following PAKs are available for download:
Ao, the host star and the Crystal Sphere of Realmspace
Various Astronomicals of Realmspace
Anadina & Coliar, the 1st & 2nd planets
Abier & Toril, the primary planets with Life
Karpri & Chandos, the remainder of the Inner Planets
PAKs completed, but not uploaded yet:
The Outer Planets & their many Moons:
Glyth and its Moons Haven, Mingabwe, & Polluter. Dwarf Moons Lylyl, Heimo, Seishi, Miruut, Thyshmae, Iremo, Hyrsylan, Guajilo, & Xullrae.
Garden and its Moons Grandchild, Yerthad, Peaceon, Retinae, Glorianus, Fjord, Locci, Dragonrock, Knurl, Sunson, Templar, & Farworld. Dwarf Moons Zen, Sigundagu, Silesia, Calidal, Jhulae, Ortho, Aernferth, Badbagrat, Aprillah, Gramfitz, Johydee, Yagub, Lathritzia, Jegred, & Kaz.
H'Catha and its Moons Lumbre & Turnbetl. Dwarf Moons Nachasorussur, Yl'rembik, Sekkatta.
PAKs not completed yet:
The Far Realm-infested stars: Acamar • Caiphon • Delban • Gibbeth • Hadar • Khirad • Nihal • Zhudun. (Stars that are sentient).
Another dreaded feature I was not able to reproduce satisfactorily were the 12 Sargassos, misty pools of space-time distortion orbiting 40 million miles (64 million km) away from the sun that slow down travel near them. Appearing like balls on the spokes of a wheel the 12 spherical dead-magic zones had a diameter of 100,000 miles (160,000 km) each. They were feared by every Spelljammer crew, which depended on magic for movement after all. I tired wormholes, black holes, nebulae, but nothing worked the way they are described so I gave up on them. Another failed object was Caer Windlauer. Simply a floating castle in space I as unable to create bump maps for asteroids to create even a simple cylinder. Perhaps a 3D model could be made someday.