If you read this blog, you may have played a fantasy game at some point. You may have played many. You may have noticed something similar about all the worlds you experience and create. The sky across many of them is the same. There is always a sun. It is bright and yellow. There is also a moon. It is white, has phases, and is tidally locked. Usually each will have an associated religion. And we are on a rock orbiting that sun, and the moon is another rock orbiting this rock. To be clear: this isn’t to say astronomy never ever finds its way into fantasy. Stars are added to the sky when needed, and over at Throne of Salt an entire post is dedicated to O’Neill Cylinders.There may be mentions of other moons in mythology, and in Yoon-Suin astronomy has explicitly advanced to observational stage, but all of this is a very limited deviation from what is normal and most fantasy settings don’t challenge the basic organization of astronomical objects in our sky, or actively allows astronomy to shape the setting. Nothing fundamental is changed or played with. Nothing about the astronomy of a world is obviously deviant from our own, and therefore none of it is fantastical. Without the benefit of added mythological details, it is boring.
The neglect of these astronomical details makes good sense from the perspective of game design. Most of them translate poorly to gameable content, and we all only have so much time in the day. But I’d argue that none of this would take much time and returns well in terms of flavor. It isn’t hard for the DM to say their world has an extra moon or ring system or a blue star. The cultural and ecological effects probably will serve as a jumping board into more setting detail, but can be ignored in the meantime. Depending on how far you go with it, that small setting detail can end up as a basis for a unique and memorable setting.
Of course, you can also go wild and have your entire setting taking place in odd astronomical conditions. Put the world in orbit around a gas giant. Make it a binary planetary system. Use superstructures, like Bishop rings or tensegrity spheres or an orbital ring. Hold them together with technology or magic no one in the setting understands- the difference would be academic, and there isn’t any reason to add in rayguns to a fantasy setting unless you want to. There’s a massive deposit of excellent fodder for fantasy heretofore untouched in astronomically inspired settings.
Enough talk. Here are some examples, for your pleasure:
Watchers on the Deep– Dozens of tensegrity spheres tethered together hold all the agriculture and society high above the choking and dark atmosphere of a Venusian or Jovian Planet. Margins of society cling to the sides, growing vines for food, ever vulnerable to fearsome weather effects. Nobility rules from the well protected apex. Deeper down, ruined spheres float just below the cloud line, occasionally poking their forgotten spires up over the terminator. Other tensegrity continents have been seen but never communicated with.
Wrathful Sky– Normal planet, but orbits a deadly blue star that makes daytime unsurvivable for humans in the long term. Agriculture still utilizes daylight, but all cities and settlements linger below the surface. War is conducted along underground causeways, dug long ago, or in times of desperation above the ground during daytime. Exile is death for most, but even older cities jut up into the sky, defiant and beautiful, cursed and abandoned.
The Tides– Heavily aquatic world orbits barycenter shared with another similarly sized world. The only certainties in this world are death, taxes, and tides. All permanent sedentary cities and settlements designed with massive tidal flows in mind, utilizing it for energy and aquaculture. Cities built on and wars fought from the back of massive turtle dragons. Below the tideline, treasures exist, waiting to be seized by the brave and the foolish. Get in and out before the ocean takes you. Likewise, some ruins are only accessible at highest tide. On occasion, something from the nearby world drops to this one.
Tower of Heaven– Bishop ring. On Lagrange point. Solar screens that provided day and night cycle for the ring have long since shattered, except for one moving back and forth near the top of a massive spire stretching towards the center of the ring. The area directly below the spire supports agriculture, civilization, nations, states, empires, and wars. The rest is a hellish desert inhabited by liches, punctuated by ruins and the massive shards of the destroyed solar screens. Only fools and adventurers go there.
One of my future roommates have talked about starting a D&D thing. If they do and I end up being the DM I will employ these ideas.