A long time ago I decided to build a campaign setting. However, I wanted it to be more than just a setting, but a unique kind of experience (almost like a new tabletop system but not quite). I started with a general concept, and then went through the shopping list of variants in the D&D 3.5e d20 System Reference Document (SRD) / Unearthed Arcana (UA) book for variants which fit the feel of the setting I was going for. I then took those variants and combed through them to make their respective terminologies mesh together into a coherent whole. I’ve now solidified what kind of experience I’m going for.
First and foremost, I wanted this to be a setting where time matters. The “15-minute work day” is entirely impractical because people (and villains) will advance their goals regardless of whether the PCs bust down the door and stop them. “You have 8 hours before they kill the princess” is a very real thing, and if you fail to save the princess in that time period then the princess will be killed (and the players will move along splitting plotlines based on it). The “game clock” is very real and increments by seconds, rounds, minutes, hours, and days on a consistent basis. Because the 15-minute workday is impractical, casters/etc. should not (and often wouldn’t want to) ask the party to stop and rest for the night. In response to the elimination of the 15-minute work day, Dailies/Spellcasters/Psionicists/Artificers have short-term energy recharge methods that are unique to each of them (similar in concept to taking a power nap). Mundanes have their innate enduring power emphasized.
For the Players
Hyperion Voyages takes place essentially “3000 years after the typical D&D setting”. That means that space travel, nanotechnology, hacking, cyberspace, corporate espionage, and alien cultures are the bread and butter of a typical campaign. To an extent, in Hyperion space it’s a post-scarcity society. Technological advancements in food reproduction, affordable housing, public transportation, widespread freely-accessible basic education, and medical care have essentially-eliminated war, homelessness, starvation, an uneducated workforce, and long-term disease. That’s not to say that there’s no unemployment or that everyone thrives, but everyone can at least survive, feed their children, home-school them if necessary, and not have to worry about debilitating illness. On Hyperion worlds anyway, anyone can be anything they want if they apply themselves for long enough.
Depending on what world you visit and what nation you happen to be in, this campaign setting exists in a mixture of modern day, futuristic, medieval, and other locales. In one session, you might be fighting alongside knights in plate mail, and in another you might be running from “laser”-shooting robots. This is made possible because the minor trappings of a given locale (such as a dossier, a toaster, etc.) can be handwaived away as givens. We don’t need stats for them.
It might seem like the variants used will make a Hyperion Voyages campaign overall a lot easier challenge-wise. I recognize that, which is part of why the sessions I write generally aim to be a lot more difficult than your standard fare, particularly through smart environment implementation (such as not having bland flat terrain) and smart NPC/monster implementation (such as actually using their environment to their advantage).
Again, everything described below is very much still open for discussion, but I do already have a very rough campaign setting in mind. Feel free to make suggestions.
All that said…
Welcome fellow Hyperion to this most unusual kind of D&D, D&D in space! This is NOT Spelljammer™, Shadowrun™, Traveler™, or Gamma World™. The author has read hardly any of the source material for those games nor do they remotely intend to wholesale copy any of those settings here, so consider this a completely unique campaign setting.
For the GM
This setting works under some general assumptions. Primarily, the cardinal rule for building a setting: “If the setting says it works like that, it works like that, period, usually because someone in the past researched how to make it work like that.” It also assumes that “if there’s a minor thing that magic can do, there’s no reason society can’t have a psionic version of it via research”. Additions to the incarnate power to bring it more in line with the permanency spell (such as the addition of non-personal categories and with that the addition of psionic teleportation circle) are an example of this.
There are of-course bans in place, but these bans are mostly from player access. Much like the (albeit poorly-executed) difference between Level Adjustment (LA) and Challenge Rating (CR), there are some things to which players specifically should not be allowed access. If some effect would say that a player would gain access to a banned effect or object, the result fails (or fizzles if you wish to flavor it that way) not only because the GM says so, but because they can potentially break the setting itself without much thought into the effect’s implications.
All that said, this setting tries to apply a sense of realism to the play mechanics. It’s understandable, for example, for a person on any given task to be much more likely to do an average job than a piss-poor job or an exemplary job. Thus, the “Bell Curve Rolls” variant is in place. It’s also much more understandable for you to not have a 10 Hit Point (HP) buffer before death, so the “Death and Dying” variant is in place. People should be able to attempt tricky methods to accomplish a task, so the “Press Your Luck” system using the “Variable Modifiers” variant is in place. People in a modern/futuristic setting aren’t as likely to be walking around in full plate armor, so the “Defense Bonus” variant is in place. More-realistic armor should soften blows, so the “Armor As Damage Reduction” variant is in place. Vancian Magic is an alien concept for most new players, so the “Spell Points” variant is in-place (albeit heavily modified for fairness).
All of these variants have been tweaked so that they mesh and work well together, so please do not remove a variant or significantly modify it unless there’s a note saying how or where you can.