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

 * 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 at all possible — once someone figures out how it works at all.
 * A.I. Is a Crapshoot: AI gradually go insane unless "brakes" (software mental blocks) are installed. Creating unbraked AI is one of 3 areas condemned as "maltech".
 * 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.
 * 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 by the Silence.
 * Genetic Engineering Is the New Nuke: There are impressive achievements, but after the Scream mostly by Eugenic Cults (which used to be outlawed, and lately are seen as a particularly gross kind of slavers) and the Zadak (who were broken by the Scream too, and decided to blame humans, so there's not a lot of friendly contact).
 * Gone Horribly Right: Hilariously benevolent Robot War. The Secret Police AIs had limitations set dangerously loose, but very thorough and redundant exactly because no one wanted them to turn on the humanity any more than ordered. And then the Terran Mandate grew shockingly tyrannic and lawless even by the standards of those who installed them… so eventually 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.
 * 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.
 * Nuclear War: The "nuke snuffers" became widespread: a single frigate can suppress chain reactions over a whole hemisphere, and common ground defences of developed colonies include grids of these much more powerful and better defended than orbitally based version. But since these can't deal with arbitrary sort of fission, once a place is radioactive wasteland, it remains mostly inaccessible for centuries, as usual. Nuking still happened on some planets, but it requires much sabotage first.
 * 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.
 * Schizo-Tech: Due to all places regressed below Golden Age levels, but to different degree.
 * The Singularity: Not long before the Scream the Terran Mandate's core worlds 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.
 * Servant Race: It's the maltech crime #1 ("Thou shalt not make tools of humankind"). Eugenic Cults try all the time, but have to do it in isolation or otherwise hidden from anyone who could object energetically. Harmony Lords of Zadak have "Changed" servants made of captured humans.
 * Standard Sci-Fi Fleet: Common hulls come in basic types split in 4 size classes.
 * Fighters: Fighter, Shuttle. — Generally in-system FTL vessels, since their little spike drives are too slow to be practical for interstellar travel with their tiny cabins and limited lifesupport. 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, Heavy Frigate ("we can't afford a cruiser"). — Still 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.
 * Capital ships: Battleship, Carrier . May carry Frigates.
 * 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).
 * There are many custom ones, including battlecruisers. Scavengers alone have Far Scout (Frigate size), Colony Ship (cruiser sized cargo ships turned into mobile habitats) and Factory Ship types.
 * 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. In the sample area (Hydra Sector) with 25 named planets and stations, 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, Powered Armour, laser pistols, etc.
 * Pretech (pre-Silence: moderately advanced for Golden Age, now the best of non-unique capabilities). Personal Deflector Shields, psitech, etc.

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.
 * Hit Points
 * The Six Stats: D&D style.
 * Splatbook: "Mandate Archives" series.

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, can be part of assets if they work for someone, or start a new faction, 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…
 * 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 are a Wealth asset attacking with Wealth vs. Force, i.e. it's one unit that doesn't care about how strong your military infrastructure is, if your faction's strong side is economy, you can buy better forces, that's it — though they have extra upkeep cost.
 * 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 . And possibly one-time growth if the faction had Goal to seize that planet and now accomplished it, but possibly becomes the target of others willing to seize it in turn. 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.