Stars Without Number

Stars Without Number is a Sci-Fi RPG from Sine Nomine Publishing, with a D&D retroclone/OSR-like engine and its own setting.

There's also fully compatible and more Post Apocalyptic companion game Other Dust, about living with Grey Goo and/or insanity.

Character Class system is kept very basic in the Original Edition. Revised Edition only gives special abilities instead of statistics (though one of Warrior's is HP bonus and Attack bonus), and adds Adventurer as multiclass having lesser versions of two classes.

Setting
"As humanity is the image of God, so the Imago Dei is the shadow of His red right hand."
 * After the End: The setting is at the era of slow recovery 6 centuries after a Terminally Dependent Society lost its cornerstone and was mostly ruined. "The Scream" killed or drove insane everyone with psychic powers worth a damn, which was quite common in humanity (and other major spacefaring species), and as such also turned all psionic dependent devices (a lot of high-tech machinery and exotic material manufacture) into useless souvenirs and disabled interstellar travel. New generations of psychics emerged, but without correct training they tend to die or go insane before becoming useful. Which led to dark age of "the Silence". Even after this issue is mostly solved, there are fewer of them (one of the main reasons for large number of psychic talents being interstellar travel), not anywhere as well-trained (due to lost knowledge), and nobody considers such abilities reliable after being burned once, so everything that required a psychic user has to be converted to less arcane interfaces if possible — once someone figures out how it works at all.
 * By the Eyes of the Blind/Implausible Deniability: The Shibboleth — malicious and weird aliens protected by psychic field. It doesn't work on psychics damaged by Torching or non-psychics subjected to imitation thereof, but there's little can be done except destroy the source of problem and probably get blamed for its crimes despite independent video evidence to the contrary, since aversion field sticks indefinitely on those affected.
 * Brain-Computer Interface: Late-era technology (especially Terran and after The Singularity).
 * Cyborg: Implants are as common as their cost allows from TL 4 up.
 * The Dark Arts: "Maltech". The Terran Mandate used to have Perimeter Agencies whose entire job was to sniff out such projects and shut down or contain. There are a few splinters still active, though mostly devolved into intelligence agencies that remember how to deal with sneaky high-tech adversaries.
 * "Thou shalt not make tools of humankind".
 * Making Servant Races of humans (it can be muddled in the area of creatures originally not considered equals, but so is AI development). There are Eugenic Cults trying all the time, but have to do it in isolation or otherwise hidden from anyone who could object energetically. And often have slaves Turned Against Their Masters despite all precautions. Harmony Lords of Zadak have "Changed" servants made of captured humans, but it's not widely known either (the road to their planet is forgotten).
 * Permanent tranquillity inducing neurochemical conditioning, since these things obviously can be readily used to produce docile slaves, even if more commonly are self-administered (in particular by some Buddhist sects ).
 * "Thou shalt not create unbraked minds." AI gradually go insane unless they have "brakes" (software mental blocks) preventing them from using full capabilities to obsess over something. Aside of people who are pants-on-the-head insane themselves, it can be tempting because given enough raw power, AI tend to go through Mad Scientist phase and design some Crazy Awesome toys — before diving further into madness and destroying themselves and/or everyone around. Removing brakes from an existing AI or failure to install them in the first place.
 * "Thou shalt not create devices of planetary destruction." Things that can make habitable worlds stop being habitable, or even worlds, from extreme biowarfare techniques and Grey Goo to massive extradimensional rifts and unstable time-stop bubbles.
 * Heavy orbital bombardment is "solved", since normally colonies are supposed to have "braker guns", gravitics defences designed to sweep away asteroids, rods and other long-range kinetic threats you can see coming. If those were installed before the colony got shut off, still work, and not sabotaged, that is.
 * Nukes are supposed to be neutralized and beneath notice, but not quite so. Nuclear War rarely actually happens since the "nuke snuffers" became widespread around the early interstellar age: a single frigate can suppress chain reactions in a few kilometres just with its standard defences, or over a whole hemisphere with a dedicated orbital defence system, and common ground defences of developed colonies include grids of these much more powerful and better defended than orbitally based version. Again, if those were installed before the colony got shut off, still work, and not sabotaged. But since these can't deal with arbitrary sort of fission, dirty bombs still work and once a place became a radioactive wasteland, it remains mostly inaccessible for centuries, as usual. The "dimmer fields" can, but they got much smaller range, so if a planet got full defence infrastructure (which doesn't happen often enough), they'll suppress excess radioactivity around the cities and cleaning vehicles, and gradually filter the fallout, so it's not inconsequential, but less than apocalyptic. There are rumours about ways to shield enough of space from nuke snuffers, however.
 * Also the Terran Mandate used to have long-range missiles with gravitic countermeasures and non-nuclear warheads using extradimensional rift to the effect comparable with high yield fusion warhead (except fallout from the igniting nuke).
 * Deflector Shields: Modest personal and vehicle only, presumably because they can't scale it up enough to withstand ship grade weapons at all, or without consuming more power than a ship can spare.
 * FTL Travel: There are psionic jump gates and spike drive for jumping drilling. Ironically, ships with spike drives were used more by the planets that couldn't afford jump gates and crowds of strong psychic operators for them, which became yet another reason why frontier worlds were less crippled.
 * Genetic Engineering Is the New Nuke: There are impressive achievements, but often by Eugenic Cults (which used to be outlawed, and lately are seen as a particularly gross kind of slavers), especially after the Scream when Perimeter agencies supposed to hunt them mostly vanished, and the Zadak (who were broken by the Scream too, and decided to blame humans, so there's not much of friendly contact).
 * Gone Horribly Right: Includes a hilariously benevolent Robot War. The Secret Police AIs had limitations set dangerously loose, but very thorough and redundant exactly because no one wanted them Turned Against Their Masters. Then the Terran Mandate grew shockingly tyrannic and lawless even by the standards of those who installed these AIs… Then they noticed that resistance to their rule is not merely tacitly allowed, but organized by those very AI on which they relied for controlling the populace. And then The Scream swept away any semblance of organization.
 * Humans Are Psychic in the Future: After interstellar travel became common, psychic talents didn't become common, but began to crop up in amounts impossible to ignore. And then enough to employ on industrial scale.
 * Human Popsicle: Cold sleep pods exist, but quality varies, especially in massive storage arrays. Thawing is a slow and finicky process, and in less than ideal conditions accidents happen. Some people discovered the hard way that "the entire batches of sleepers awaken as crazy ghouls who find each other unappetizing" is among the possibilities.
 * Organic Technology: Humans have gengineered some species for terraforming or as war beasts, but the Zadak run with this as far as they can.
 * Lost Technology: Called "Pretech" (pre-Scream) — covering non-trivial psitech and all the stuff with lost manuals. Some colonies dropped to XX century level or lower via misfortunes much less serious than the Scream. Near the end, the Terran Mandate itself was hobbling colonies, simply because its grasp was slipping while Control Freakery increased.
 * Nanomachines: On TL5 to Mandate Core worlds used to be around the level of Schlock Mercenary, including "just roll his head into it" grade life-support bags. Except with easier artificial gravity. Some specialized nanofabs remain here and there.
 * Psychic Powers
 * Psitech
 * Robot Roll Call: They are rarely as competent as humans employees without being more expensive, however. Common robot expert systems are not good at wrestling complex problems. Thus e.g. there is an option for a starship to have robots as most of the crew, but it's not common and works better when there are repair facilities for robots and ship, with actual living mechanics. Or a true AI.
 * Religious Robot: The Imago Dei, AI fleets/knightly orders who belong to every faith that had a sect accepting AI as valid worshippers. Worrisome deviations happen, but generally tend toward Knight in Shining Armor. They decided that since Mandate got rotten and cannot be arsed to protect humanity, it's their duty now, left the Core Worlds and built shipyards. Since they were far out on the frontier busy fighting and rebuilding, and AI can't be psychics, they barely noticed the Scream at all.


 * Schizo-Tech: Due to all places regressed below Golden Age levels, but to different degree.
 * The Singularity: Not long before the Scream core worlds of the Terran Mandate were flooded with things developed by AIs and at best poorly understood by the humans.
 * Sinister Surveillance/Surveillance as the Plot Demands: Up to Panopticon facilities with AIs sifting through all intelligence gathering. And then Dust (you thought bugs were bad, try to hide from Nanomachines) controlled by them.
 * Shout Out: SWN is rather visibly influenced by Schlock Mercenary, Star Frontiers and Warhammer 40,000, among the other things.
 * Standard Sci-Fi Fleet: Common hulls come in basic types split in 4 size classes.
 * Fighters: Fighter, Shuttle. — Generally in-system vessels . Destroyed with all hands at 0 hit points unless the attackers actively try to disable it without blowing up. Swatted by Cloud class weapons, suffers more from Flak weapons, hard to hit with Clumsy weapons.
 * Frigates: Free Merchant, Patrol Boat (built for speed), Corvette (average), Heavy Frigate ("we can't afford a cruiser"). — The largest ships that can land. May carry cargo lighters, drop pods, lifeboats. May have most "proper ship" equipment.
 * Cruisers: Bulk Freighter, Fleet Cruiser. — Cannot land, thus need to carry at least cargo lighters to reach planet surface. May carry Fighters. May have hydroponic bays, Mobile Factory or mass cryo-chambers.
 * Capital ships: Battleship, Carrier . May carry Frigates.
 * There are many rare/non-standard/custom hulls, including battlecruisers (up-armored cruiser with juiced up powerplant and thrusters). Scavengers alone have Far Scout (Frigate size), Colony Ship (cruiser sized colony or cargo ships converted into mobile habitats) and Factory Ship (cruiser sized mobile shipyards) types.
 * Small craft considered equipment rather than separate vessels includes cargo lighters (surface-to-orbit shuttles), drop pods (like cargo lighters, but with armor, countermeasures and better engines), lifeboats (single use shuttles with anabiosis equipment, etc).
 * Space Station
 * Super Human Trafficking: In different times and places Psychics were and are treated… differently.
 * Superpower Meltdown: Psychics tend to cause themselves permanent brain damage when they use powers without basic training or too much.
 * Tech Levels: Rather generic. 0 is Stone age level. 5 is the highest that merits a classification, but in the sample area (Hydra Sector) of 25 named planets, there are two rated "4+", so good luck finding full 5.
 * Medieval technology.
 * Low industrial, XIX century technology.
 * XX century technology — lack of fusion power is not quite ruin, and fun toys like Grappling Hook Pistols and monochrome Night Vision Goggles are here.
 * Baseline postech (early interstellar age, or somewhat backward for Golden Age) — with cyberware, antigrav cars, Tractor Beams, Powered Armour, laser pistols, etc.
 * Pretech (pre-Silence: moderately advanced for Golden Age, now the best of non-unique capabilities). Personal Deflector Shields, most of psitech, etc.
 * Terraforming: On the frontier often half-done, or malfunctioning machines cause problems as much as they solve.

RPG Mechanics

 * Character Class: Wide general classes not unlike Alternity.
 * Damage Reduction: Armor (as opposed to AC, and used alongside it), for vehicles and spaceships.
 * Background Based System:
 * In the Original Edition — choose Background Package for origin — class — one of Training Packages for that class. Together packages define starting skills.
 * In the Revised Edition — choose Background (gives free skill and either picked/default optional skills or rolls for random skills or stats increase) — class — Focus (not class dependent) which gives a special ability and/or bonus level in a skill, and usually can be upgraded to higher level; Warriors and part-Warriors also pick 1 level in any combat related Focus relevant to their backgrounds, Experts and part-Experts in non-combat one — 1 non-psychic skill.
 * Cybernetics Eat Your Soul: Downplayed. All cyberware inflicts permanent System Strain, and some also temporary on activation. So the more augmentation, the less a character can use biopsionic healing or pretech healing and stimulant drugs, since those also inflict System Strain, and upon overload one cannot benefit from either.
 * Design It Yourself Equipment There's usual starship building from hulls and components. Revised Edition allows to build mods into the hull, i.e. make variant ship classes. There's e.g. non-interchangeable mounting for particular equipment saving space and power, or special mounting for oversized equipment, which allows things like courier vessels built around overpowered spike drives, or Fighters with torpedo launchers (normally reserved for Frigate size).
 * Ace Custom: Revised Edition introduced "Mods" for personal equipment, vehicles and starships. That require extra maintenance beyond off-the-shelf hardware.
 * Hit Points
 * The Six Stats: D&D style.
 * Randomly Generated Levels: Core books include random generators for a sector map, general characteristics of the "main" worlds, secondary worlds, alien species, Mega Corps, etc. "Resource tables for random generation of names, NPCs, religions, political parties, architectural styles, and room furnishings excel in generating the kind of fast, smooth content that sandbox gaming demands. " Mandate Archive: The Dust got random tables for nanobot based pretech.
 * Rules Conversions: Frontier Explorer fanzine issues 6 and 8 have articles on conversion of Star Frontiers to SWN Original Edition.
 * Sourcebook
 * Rules Expansions:
 * Darkness Visible — more detailed rules for Cloak and Dagger stuff.
 * Mandate Archive: Martial Arts — rules expansion and examples of armed and unarmed martial arts.
 * Suns of Gold — Merchant Campaigns
 * Starvation Cheap — Military Campaigns
 * Skyward Steel — Naval Campaigns, including black ops.
 * Mandate Archive: Stellar Heroes ("Face the perils of a heartless cosmos with a single daring hero") — solo game rules plus a free side adventure.
 * Splatbooks: Includes most of "Mandate Archives" series.
 * Engines of Babylon ("The Cold Stars Await Your Tread") — more vehicles, more maltech, rules for low-tech system ships.
 * Relics of the Lost ("The Treasures of a Dead Age Await") — various extra toys like low-tech and high-tech weaponry, robot armatures, fancy pretech, maltech projects.
 * Mandate Archive: Bannerjee Construction Solutions — common space stations of the frontier.
 * Mandate Archive: Bruxelles-class Battlecruiser ("An Iron Ghost from a Dead Age...") — a typical Terran Mandate warship.
 * Mandate Archive: Cabals of Hydra Sector ("Shapes Without Names") — more sample secret societies, using Darkness Visible rules.
 * Mandate Archive: The Dust ("A handful of fear from a dead empire") — nanoswarms and some nanobot based pretech.
 * Mandate Archive: The Imago Dei ("Paladins of the Long Silence") — AI knightly orders in space.
 * Mandate archive: The Qotah — sample aliens.
 * Mandate Archive: Red Sangha Mercenary Corps — Buddhist Battle Monks In Space.
 * Mandate Archive: Scavenger Fleets ("Nomads of the Uncharted Sky") — stray space fleets that became, well, wandering groups of scavengers/traders/mercenaries/etc.
 * Mandate Archive: Transhuman Tech ("Tools To Be More Than Human") — transhumanism and post-scarcity societies.

Faction Strategy
SWN includes an awesome system of faction strategy, which can be used as dynamic backdrop or involve player input: PCs can donate funds or assets, destroy assets, can be part of assets if they work for someone, or start a new faction on their own (e.g. if you colonized a planet not in the name of an existing faction, what you already have can be represented by a faction with [Colonists] primary tag, along with one automatic [Planetary Government] tag it gives).


 * Turn-Based Strategy:
 * Cloak and Dagger/Spy-Versus-Spy: Cunning based (i.e. intelligence) attacks, [Stealthed] Special Forces assets smuggled in… Two types of factions are made for this: Machiavellian gives bonus to one Cunning attack per turn, Secretive purchases all assets [Stealthed] (i.e. it can be just another legitimate or underworld enterprise, only happens to be owned by a cell of some secret society — if they buy a Wealth facility or Party Machine for extra income, too, and sell if it got unmasked, before attacked), rather than as upgrade to Special Forces only and for extra price; of course, a planetary government can still veto formation or movement of most military units in the first place without knowing who really stands behind them.
 * And then Darkness Visible expansion builds another town on top of this.
 * Corrupt Politician/Double Agent/Honey Trap/etc: A lot of Cunning assets represent subversion and turncoats, and most can be [Stealthed] until they are used to attack or defend (and then again, if they survive).
 * Deep-Cover Agent: Few things can unmask Stealthed assets without wasting an Action. Being used for attack or defence unmasks, but not other actions. So a Demagogue, Lobbyists or Lawyers need to show their true colours to be useful, but Surveyors help to create Base of Influence and move on, a friendly Commodities Broker just sits there and reduces costs of all new assets, while Pretech Researchers allow to buy non-military assets of too high TL for the planet…
 * Loose Lips: Informers can reveal all Stealthed assets of a faction, and don't even need already visible assets to try. And are by far the cheapest way to do this (but require to waste an Action the faction could spend on making money).
 * Mata Hari: A successful attack from Seductress instead of inflicting damage makes the target reveal any Stealthed assets of its faction currently on the planet. Also, can be attacked only by Special Forces (granted, this includes lots of things from Hitmen or Zealots to Demagogue or Lawyers).
 * Secret War: A faction with high Cunning and/or advantage in using it (and good income) can take over a world with Cunning and Wealth attacks only, nothing as blatant as sending fleets of dropships. Against attempts to purge exposed assets by direct force, guerillas jump in the way, moles get underfoot or Seditionists paralyse the whole military units via divided loyalties.
 * Of course, some factions have equal advantage in defence, and Imperialists or Warlike factions can try to «catch up with the opposition and return the favor… physically.»
 * Eagle Squadron: A faction can buy assets anywhere it got a Base of Influence and move anywhere in range of logistic facilities. And the local government may veto military units, but doesn't have to, so many shenanigans are possible, including formation of an unit on allied territory and then moving it to one's own (this wastes an action to move, but can be meaningful even without alliance mechanics: effective TL and cost vary per planet, and enemy may have less opportunities to sabotage it).
 * Hired Guns: Mercenaries have extra upkeep cost, but they are a Wealth asset attacking with Wealth vs. Force, i.e. it's an unit that doesn't care about how strong your military infrastructure is, if your faction's strong side is economy, you can afford more and better hired guns, that's it.
 * NGO Superpower: Mechanically, the only intrinsic difference between the factions are tags. And there's no restrictions for acquiring [Planetary Government] for some or other planet, any faction could do it via successful Seize action (if it's Secretive, well, there's "Secret Masters" World Tag). Also, mechanically its only effect is rights to allow or veto raising at the planet (or move in) most military units . Which involves "implicit" military force (i.e. it sits in garrisons as a art of infrastructure and cannot be readily thrown here or there). And possibly one-time growth if the faction had Goal to seize that planet and now accomplished it, but now the others can do the same. It can be much more useful to have a separate allied faction as a government (more actions and different strengths).
 * Privateer: blockade fleets — plunder the target in addition to damage.
 * Servant Race: Eugenic Cults have Gengineered Slaves as Force assets of Military Unit or Special Forces type, and bonus to attack or defend with them. They are comparable with Militia at fighting, but cheaper by half and tougher by half, i.e. good Cannon Fodder.