Hard Science Fiction

As a PC in a hard science fiction game, you can expect a setting that is potentially years in the future—maybe even a few hundred, after humans managed not to wipe themselves out, but instead colonized the solar system. In such a scenario, colonies stretch to the moon, a variety of space stations and orbitals, Mars, cloud cities in Venus's upper atmosphere, hollowed-out asteroids in the asteroid belt, and many other outposts farther out on the moons of various supergiant planets. Your challenges come in dealing with the limitations of real world science (vacuum, the effects of low gravity and acceleration, long ship travel times, and so on) even as you work with and against various factions, new technologies, and maybe the implications of brand-new discoveries that threaten to set what everyone has long accepted as the standard limits of science on their head.

If you've read or watched the Expanse series, you're familiar with a particular type of hard science fiction setting. Other examples might have a contemporary setting where some new element threatens to upend society, such as in The Three-Body Problem by Liu Cixin and The Power by Naomi Alderman, to name just a very few.

Skills: Refer to the Science Fiction Skills table for a list of skills you can choose from when creating and advancing your character. Your choice of background skill, and possibly the extra skill you might get if you also choose a meaningful inability, also come from the same list of genre skills.

Character Species: Hard science fiction settings usually center on Humans (in the absence of any real-world evidence of aliens), whether or not your GM is using the optional species rules.

Foci: The list of suggested hard science fiction foci is more restricted than the larger list of space opera foci because some technologies (and many environments) commonly portrayed in space opera are not likely to ever be developed or found. Perhaps other foci are available in your game, but possibly only after the discovery of some previously unknown alien supertech.

Suggested Foci for a Hard Science Fiction Game

• Builds Allies
• Carries a Gun
• Controls Beasts
• Doesn't Do Much
• Entertains
• Explores
• Fights Dirty
• Fights Unarmed
• Fights With Panache
• Fuses Flesh and Steel
• Fuses Mind and Machine
• Hunts
• Infiltrates
• Leads
• Masters Weaponry
• Never Says Die
• Performs Feats of Strength
• Sneaks Through the Shadows
• Solves Mysteries
• Stands Like A Bastion
• Talks to Machines
• Tends to the Wounded
• Works for a Living

Equipment: Refer to your type's suggested equipment bundle or the Science Fiction Equipment table for equipment you can choose from when creating your character and for options that might be available to your character when you have more currency to spend.

Manifest Cyphers: These cyphers are available only in settings where weird prototypes or mysterious alien tech exist.

Wound Treatment: Hard science fiction tends to be a realistic genre. Using treatment to remove a wound takes ten minutes for a minor wound, one hour for a moderate wound, and one week for a major wound.

Currency: The currency underlying price categories in a science fiction setting usually are nonphysical credits controlled by a hidden financial network, accessible by a variety of different machines, including your character's smart device.

Background Options: Each type includes suggestions for your character's background. Choose one or create your own.

Genre Abilities for Your Hard Science Fiction Character: At tier 3, your character gains a mid-tier ability from the list of Science Fiction Genre Abilities at the end of this chapter, and at tier 6 you gain a high-tier ability from the same list. In addition, at tier 6, you can replace one of your mid-tier genre abilities with a different mid-tier ability. See that section for additional stipulations that might affect your science fiction genre ability choice.

Hard Science Fiction Types

• Diplomat
• Engineer
• Medic
• Noble
• Operative
• Pilot
• Soldier

Creating Hard Science Fiction Characters

Before choosing a type, create your core character, which (as a quick reminder) grants the following:

• 8 Might / 8 Speed / 8 Intellect
• 6 additional points to allocate in Might, Speed, and/or Intellect
• Capacity to take three minor / three moderate / three major wounds
• Effort: 1
• Cypher limit: 2
• Freely use light weapons
• Cannot freely use any armor
• Two genre skills
• One additional genre skill in exchange for an inability ina genreskill
• Starting equipment

[!example]

Adapting Types From Other Genres

If you want more type options than those presented in one science fiction subgenre, your GM may allow you to choose a type from another subgenre (especially between hard science fiction and space opera) andconvertitwithjustalittlework.Typesfromthepostapocalypsegenremayrequiremore customization—possibly a slight boost because they’re a little less capable in certain ways. Work with

your GM to see what’s possible. It might also be possibletochoose types from other genres. You’ll want to work with yourGM, and will need to adapt or reskin the typea bit more comprehensibly. For instance, a Paladin or Mage from the dungeon fantasy genre might make an interesting science fiction character, buttheir equipment, background, general description, and basis for their abilities would all require a rework. Any magic these types do would have to be reimagined for science fiction as energies generated by devices they carry or someother in-world source.

Diplomat

You play the long game while everyone else is reacting to the latest provocation. You know how to smile, flatter, and offer gifts to your potential new ally, even when you’d prefertojump across the table and strangle them. Sometimes less obvious means are required for negotiation. When possible, you try to discover as much as youcan about who you’ll be talking to. If they won’tdo as you ask initially, perhapsthey’llmakeadealinlightofsomethingtheyneedthatyoucanhelparrange—or,ifyou’renot above making veiled threats, becauseyou know something they’d prefer not come out. You understand others, so you’re probably someone who can advise and assist teammates and serveasan intermediary between your allies and strangers. Many times, a bit of diplomacy—or a bit of

distraction through verbal diversion—is what allows the rest of the team to reach a sensitive location, talkyourwayoutofthesame,or,whenthestakesarereallyhigh,avoidescalatingtensions.

Background Options

• Your family was part of an asteroid co-op, but your big mouth got you voted out and now you seek to better yourself.
• You brokered a deal between two multiplanetary corps lastmonth, ending years of hostility.
• You, your parents, and your siblings went down in a moon shuttle crash when you were young. You’ve always suspected a conspiracy was behind it but haven’t found any hard evidence. Yet.
• You were recently fired by the new head ofthe government bureau that employed you.
• One of your colleagues, a fellow analyst in a spy agency, was recently charged with treason.
• You were last in your graduating class, roundly reviledby your classmates,yet here you are, determined to make a difference and prove them all wrong.
• You can’t say anything about your biggest diplomatic success lest you risk renewed war.
• Your grandchild helps keepyou doing what you do—they deserve a better future.

Diplomat Abilities

You gain all of the following benefits: Able to taketwo more minor wounds and one more moderate wound Add+1 to Speed Pool Add+3 to Intellect Pool Add+1 Edge in Pool of your choice Freelyuselightandmediumweapons Freely use light armor

At tier 3and tier 6, choose anability fromthe Science Fiction Genre Abilities list

Connected (2+Intellect): You know peoplewho get things done—not justrespected people in positions of authority, but also a variety of online hackers andregular street criminals. These people are not necessarily your friends and might not be trustworthy, but they owe you a favor or two. When you use this ability, you remember or otherwise establish a level 2 contact you can reach out to in a specific location. You and your GM can work out the specifics. Effort: Increase the level of thenew contact by 1. Thisability renews when you access a new location or when at least a month has elapsed in the same location where you last used this ability. At tier 3, you can establish twocontacts in a specific location simultaneously. Enabler.

Choose the following equipment bundle to quickly outfit your character, or assemble your own starting equipment. A briefcase (vacuum-proof), a surelock (to keep others out of your briefcase), appropriate clothing, an extra set of very fine clothing, a smart device (glasses, badge, ring, and the like), abreather, an environmental tent, an everlight, two days of rations and water, a grooming and toiletry kit, and eyeshades. Your character also starts with currency equivalent to a moderately priced item.

Engineer

Listen to thoseengines hum! Wait, are those harmonics in spec? For you, every machine is a potential opportunity to learn something, to fix something, or maybe even to make something new—however temporary—from its parts. If you don’t know something, you know what archives are most likely to contain the blueprints or otheranswers you need, even if that knowledge is encoded in restricted databases. You’re a maker, afixer, and a hard-edged knowledge worker with real-world experience in all kinds of scenarios. Because of your presence, your team’s mission is more likely to succeed, rather than fail for wantofaturboencabulator.

Background Options

• Having barelysurvived a system failure in your childhood asteroid habitat,you’ve dedicated yourselftotechnical pursuits to prevent similar disasters in the future.
• Last week, the news reported that an engineering professor you studied under was murdered.
• When the dissidents attacked, they cut the main power, resulting in your parents’ deaths. You’ve sworn to one day find their leadership and return the favor.
• Your paper on an ion drive refinement means you’re still recognized in narrow circles.
• You woke up from a medically induced coma ten years ago with no memory of your past and no identifying documents. After all these years, you still have no answers.
• Last month, the engines on a tramp freighter you were trying to repair exploded.
• You recently returned from a three-year tour of the outer planet deuterium refineries.
• When the colony radiation scrubber broke a month ago, you were able to make a quick fix.

EngineerAbilities

You gain all of the following benefits: Able to taketwo more minor wounds and one more moderate wound Add+1 to Speed Pool Add+3 to Intellect Pool Add+1EdgeinPoolofyourchoice Freely use light and medium weapons Freely use light and medium armor At tier 3and tier 6, choose anability fromthe Science Fiction Genre Abilities list

Connected Knowledge (1 Intellect): You canconnect to restricteddata (via an implant, ahandheld device,aroboticdroneassistant,orthelike)thatisn’tpubliclyaccessible.AskyourGMaquestionand get a shortbut accurate answer if you succeed onan Intellect task. The difficulty is routine if it’s something anyone could learn via their own methodof access, level 3 if the sensitive or secret knowledge is primarily an engineering or scientific topic, and level 5 or higher if your GM decidesthe information is particularly sensitive or secret, whether scientific in nature or not.Last action. Expert Engineer: You are trained in engineering. At tier 6, you can become an expert in engineering if you are already specialized, but you must gain the skill normally. Enabler.

Modify Device (3 Intellect): You quickly jury-rig a piece of equipment or a powersource in order to repair or upgrade it.This requires access to appropriate parts and tools. Repair: If you succeed on an engineering task (difficulty equal to the device’slevel + 1), you temporarily repair a piece of broken equipment or an inactive power source to get a few more uses out of it. Upgrade: If you succeedat a difficulty 3 engineering task, you make the device function about 25 percent above its rated specifications. When you take a ten-hour recovery, the device breaks, requiring a full repair (as opposed to another Modify Device task) to regain its original, unmodified function. For example, you could overclocka medium blaster so that it deals 1 additional damage, modify a food printer so that each cup of coffee made with it tastes better, modify a spacecraft’s engine so that its acceleration is improved by 25 percent, and so on. Whetheryourepairorupgradethedevice,itnowhasadepletionof1–6onad20(checkeach use).

At tier 3, the modified device’s depletion improves to 1–2 on a d20. Ten minutes to complete.

[!example]

EngineerEquipment Bundle

Choose the following equipment bundle to quickly outfit your character, or assemble your own starting equipment. A set of tools specialized for engineering (including bolt cutters), appropriate clothing,a backpack, a smart device (glasses, badge, ring, and the like), a breather, an environmental tent, bolt cutters, an everlight, two days of rations and water, a groomingand toiletry kit, andeyeshades. Your character also starts with currency equivalent to a moderately priced item.

Medic

You fixpeople, reknitting their flesh, patching their rupturedorgans, and coaxing their shattered bones back together. Your bedside manner doesn’t really matter, especially when your skills are called on

during disaster or war. And your comportment matters even less in situations when you use your medicalknowledgeandsuppliestodisablefoes—sometimes,nooneexpectsamedictofightback. Your role on a team that routinely encounters challenging environments or conflict is crucial. Without yourexpertise and care, the group’s next job could prove its last. Luckily, you can also handle yourselfin a fight. In fact, either hard experience or professional training means you’re not someone who needs protection when the situation sours.

Background Options

• Rebel anarchistsspaced your small mining community and forcibly inducted you into their ranks. You escaped but still seekrevenge on their remnants.
• You served as a doctor in an orbital surgical hospital (OSH) until it was recently destroyed.
• Your spacefaring clade hunted icy bodies in the Kuiper belt,but a mistake you made ledto the death of the administrator’s child, and now you seek absolution.
• A doctor you worked under was charged with illegal organ sales last week.
• Your family helped found a Mars hab, but a criminal gang cracked it and killed almost everyone. You still dream of payback.
• Every so often, your expertise in an area of medicalknowledge is requested by the military.
• You recently finished a refresher course on space medicine at the new lunar hospital.
• Your medical intervention saved someone who turned out to be a corrupt government official.

Medic Abilities

Yougainallofthefollowingbenefits: Able to taketwo more minor wounds and one more moderate wound

Add+1 to Speed Pool Add+3 to Intellect Pool Add+1 Edge in Pool of your choice Freely use light and medium weapons Freely use light and medium armor At tier 3and tier 6, choose anability fromthe Science Fiction Genre Abilities list

Bad Medicine (2+ Intellect or Speed): With access to a medical field kit (or similar equipment), you deliberately misuse a medication normally meanttoheal, such as a skin spray, injector, or similar device. Make an attack against a creature in immediate range; the medical device is a light weapon (the attack is eased). If you succeed, they can’t take any actions on their next turn. Effort: Instead make thecreature unconscious until you use a recovery (requires twolevels of Effort). Action.

Expert Doctor: You are trained in healing.

At tier 6, you can become an expert in healing if you are already specialized, but you must gain theskillnormally. Enabler.

PreparedMedic (2+ Intellect): With access to a medical field kit (or similar equipment),you can use treatment in half the normal amount of time or treat twice as many wounds for one character in the normal time. Enabler.

[!example]

Medic Equipment Bundle

Choose the following equipment bundle to quickly outfit your character, or assemble your own starting equipment. A medical fieldkit, appropriateclothing, an armoredbodysuit, a smart device (glasses, badge, ring, and the like), abreather, an environmental tent,a single-use vacuum suit, an everlight, two days of rations and water, a grooming and toiletry kit, and eyeshades. Your character also starts with currency equivalent to a moderately priced item.

Noble

The stats for a hard science fiction Noble are the same as those for a Noble in a space opera.

Operative

You imagine yourself as the glitch in the system, or the “ghost in the machine” that gets in and then out without alerting automated surveillance until you’re already elsewhere. As far as your foes are concerned, you’re one of them, blending in with everyone else so that no one suspects you’re an operative working for the enemy.But if you are caught out, you don’t hesitate—you eliminate those who recognize youso quickly that they can’t raise the alarm. Some situations would benefit from having someone on your team already on theinside, which is perfect for you. Or at least someone who doesn’t draw enemy fire until you can slip past perimeter security to shut down surveillance and/or take out guardswho don’t realize you’re a foe.

Background Options

• Orphaned, you survived in the hidden places of the spinning space habitat and spent most of your life alone. Today, you try to break out of that life and mindset, hoping to findfriends despite how everything you’ve learned fights against that.

• Onyourlastjob,youdiscoveredthecorporationwasintoexplicitlyillegalactivities.

• Your parents’ belief that you’re a musician who plays various gigs was recently shaken.

• Your family’s moon mine was illegally seized bya megacorp. Now you work to expose and dismantle megacorps whenever you can.

• The stray data modules you grabbed on your last job turned out to contain classified info.

• They hired you to be a body double, but you fled after they told you to assassinate your targetfirst.

• Raised from childhood to be an assassin,you escaped the daily tortures to make a new life for yourself. One day you hope to find and punish those who hurt you.

• Last month you discovered that your employers in turn workfor a mysterious secret group.

Operative Abilities

You gain all of the following benefits: Able to taketwo more minor wounds and one more moderate wound Add+2 to Speed Pool Add+2 to Intellect Pool Add+1 Edge in Pool of your choice Freely use light and medium weapons Freely use light and medium armor Gain one weapon of your choice At tier 3and tier 6, choose anability fromthe Science Fiction Genre Abilities list

Escape (2+ Speed): When you roll to escape (such as slipping your restraints, squeezing through the bars, breaking the grip of acreature holding you, or pulling free from sucking quicksand) and your roll is less than a 9, treat the roll as a 9. (This means you don’t get a GM intrusion if you roll a 1.) Effort: Increase the minimum number rolled for this ability by 3. At tier 3, the minimum number rolledfor this ability increases to 12. Action. Sneak Attack (1 Speed):If you use a light weapontoattacka foe underone of the following

conditions, your attack inflicts +5 damage. (This ability doesn’t work with medium or heavy weapons.)

• You attack with surprise.
• An ally uses their action to ease your attack.
• Your foe’s defenses are hindered due to some other ongoing direct distraction.
• Your foe is unable to take their next turn due to some disabling attack or situation. First action. Spin Identity (2+ Intellect): When you roll to convince an intelligent creature (including computers and surveillance systems)that you are someone or something other than who you actually are, and your roll isless thana 6, treat the roll as a 6. (Thismeans you don’t get aGM intrusion if you roll a 1.) Thisability doesn’t let you impersonate a specific individual. Instead, you convince onlookers that you are someone they donot know belonging to a certain categoryof people. “I’m with the government.” “I’m just a simple traveler going about my business.” “Your commander sent me.” Successful uses of Spin Identity persist until you use a ten-minute or longer recovery, unless your actions or other circumstances reveal your true identity earlier. Effort: Increase the minimum number rolled for this ability by 3. At tier 3, the minimum number rolledfor this ability increases to 12. Action.

[!example]

OperativeEquipmentBundle

Choose the following equipment bundle to quickly outfit your character, or assemble your own starting equipment. A molecular blade, appropriate clothing, spray-on impact armor (ten uses), extra clothes and accessories fordisguise, a smart device (glasses, badge, ring, and the like), a backpack, a breather, an

environmental tent, a single-use vacuum suit, an everlight, two days of rations and water, a grooming andtoiletrykit,andeyeshades.Yourcharacteralsostartswithcurrency4equivalenttoamoderately priced item**.

Pilot

You’re sensitive to the slightest vibration and yaw ofion, nuclear, and chemical rocket-propelled spacecraft, honed during many hundreds of hours of test flights, combat missions, and your personal zeal for piloting interplanetary craft between moonsand planets. Your job combines sophisticated course plotting, long periods of gradual acceleration and deceleration, and, sometimes, intense moments of action where your reaction times make the difference between arriving at your destination and your spacecraft becoming one more driftinghulk in a decaying orbit. If the team’s mission requires an interplanetary trip, it’s your job to get everyone there. Should enemy craft threaten the trip, your superior piloting skills help keep everyone alive, up to and including the Soldiers who, scary as they may be, probably couldn’t last ten seconds piloting through an interplanetary naval engagement.

Background Options

• You grew up in a floating city above Venus, until a crack inthe dome required evacuation. Fancy shuttle piloting saved you, but most peopledied. Ever since, you’ve tried to improve your own piloting skills.
• After mustering out of service three years ago, you’ve been taking odd jobs piloting cargo craft.
• Raised in an experimental AI creche later deemed unethical and illegal, you’ve taken pains to hide your past, but secretly feel thatpersecution of artificial people is unjust.
• Your niece recently contacted you, asking you to teach her how to pilot spacecraft.
• You and your family were selected to be part of the first crew in a generation ship, but rebels seized it, killing almost everyone. You still harbor thoughts of vengeance.
• Crashing an experimental warcraft four months ago ended your test pilot career.
• Not long ago you returned from a years-long outer-planet survey; only you survived.
• Due at least in parttoyour long absences, your marriage fractured last month.

Pilot Abilities

You gain all of the following benefits: Able to taketwo more minor wounds and one more moderate wound Add+1 to Speed Pool Add+3 to Intellect Pool Add+1EdgeinPoolofyourchoice Freely use light and medium weapons Freely use light armor Gain one weapon of your choice At tier 3and tier 6, choose anability fromthe Science Fiction Genre Abilities list

BorntoPilot(2+Intellect):Whenyourolltopilotaspacecraftandyourrollislessthana9,treatthe roll as a 9. (This means you don’t get a GM intrusion if you roll a 1.) Spacecraft piloting tasks include specific maneuvers like safely docking the craft, turning or accelerating the ship gradually enough to avoid dangerously high gravity for sustained periods, noticing somethingunusual come up on the sensors, and so on. Effort: Increase the minimum number rolled for this ability by 3. Thisability renews when you take a recovery. At tier 3, the minimum number rolledfor this ability increases to 12. Action. Expert Space Pilot: You are trained in piloting spacecraft. At tier 6, you can become an expert in piloting spacecraft if youare already specialized, but you must gain the skill normally. Enabler.

Piloting Flourish: When you handle a spacecraft, your impressive piloting chops, diverting quips, and/or a certain something in the way you accomplish a maneuver entertains or impresses others. One creature you choose on or near the spacecraft who can see you or is otherwise aware of your maneuver gains an asset to their nexttask if taken within a round or two. At tier 3, you can impress up to three chosen creatures simultaneously. Enabler.

[STARTBOX]

Pilot Equipment Bundle

Choose the following equipment bundle to quickly outfit your character, or assemble your own starting equipment. A vacuum pistol and a weapon energy pack (50shots), appropriate clothing, spray-on impactarmor (ten uses), extra clothes and accessories for disguise, a smart device (glasses, badge, ring, and the like), a backpack, a breather, an environmental tent, a single-use vacuum suit, a first aidkit, aneverlight, two days of rations and water, a grooming and toiletry kit, and eyeshades. Your character also starts with currency equivalent to a moderately priced item.

Soldier

You’ve seen things civilians wouldn’t believe: attack ships shattering Mars domes with mini-nukes; fellow soldiers disintegrated by stray linearaccelerator fire, floating ashes their only grave marker; gravity-dropping through the silent void, praying your lidar warns you quickly enough to pop your brake rockets before youslam into the unlit enemy asteroid. The adrenalinekick of a firefight is like nothing else, but better yet is the fizzy exhilaration of another missionsurvived. Madeforcombat,you’reprobablyamongthefirstonyourteamtoconfrontarmedfoes.Yourallies with other specialtiesare probably happy to let you; not everyone can rely on combat enhancements when adversaries begin firing kinetic weapons.

Background Options

• You came of age in a megalopolis slum, doing what was necessary to survive. You left it all behind,butsometimesyoustillwishyou’dtakenacoupleofyourfriendswithyou.
• You witnessed a peace accord almost being signed two weeks ago, but an envoy vanished.
• You grew up in a farming collective that was ultimately killed by the climate cataclysm. You’ll take corporategigs, but you keep an eye out for the sorts of execs that put profit ahead of normal people’s lives.
• A comrade in arms sent you a note to look them up a few months ago because they had “news.”
• You and your sister were raised by pirates operating in the belt. You got out but she didn’t. You always wonder what happened to her but are afraid to find out.
• You mustered out of service about a year ago, and you’ve mostly spent through your payout.
• Last week you were offered a job training anACI (artificial combatintelligence) from your brain.
• You completed a job serving as a diplomat’s bodyguard six months ago, but now they’re dead.

Soldier Abilities

You gain all of the following benefits: Able to takethree more minor wounds and one more moderate wound Add+2 to Might Pool Add+2 to Speed Pool Add+1EdgeinPoolofyourchoice Freely use all weapons

Freely use all armor Gain one weapon of your choice At tier 3and tier 6, choose anability fromthe Science Fiction Genre Abilities list

Combat Enhancement (2+ Speed or Intellect): Your military combat enhancement—likely some kind of nerve implant, subdermal hardware, or genetic modification—lowers your reaction time in response to unexpected threats so that you’re rarelysurprised. Roll initiative as normal, but if your roll is less than a 15, treat the roll as a 15. (This means you don’t get a GM intrusion if you roll a 1.) Effort: Increase the minimum number rolled for this ability by 3. At tier 3, the minimum number rolledfor this ability increases to 18. Enabler.

ExpertCombatant:Youaretrainedinaspecificweaponattackofyourchoice,suchasswords,axes, or bows; or in a broader category of attacks such as light bashing weapons, light bladed weapons, light ranged weapons, medium bashing weapons, medium bladed weapons, medium ranged weapons, and so on.

At tier 2, you can choose to become specialized in the same attack method you chose at tier 1, but youmustgaintheskillnormally. At tier 6, you can become an expert in a specific attack method (either the one you chose at tier 1 or another weapon skill you’re already specialized in), butyou must gain the skillnormally. Enabler.

Push Implant: After attacking, you can activatea combat implant to makean additional attack as an extra action on your turn. Doing this inflicts a moderate wound on yourself.This ability renews after you use a ten-hour recovery. Enabler.

[!example]

Soldier Equipment Bundle

Choose the following equipment bundle to quickly outfit your character, or assemble your own starting equipment. A vacuum rifle and a weapon energy pack (50 shots), appropriate clothing, an armored bodysuit, extra clothes and accessories for disguise, a smart device (glasses,badge, ring, and the like), a backpack, a breather, an environmental tent, a single-use vacuum suit, a restraint(bindssubject’s wrists together), an everlight, two days of rations and water, a grooming and toiletry kit, and eyeshades. Your character alsostartswithcurrencyequivalenttoamoderatelypriceditem.

[!example]

Hard Science Fiction or Space Opera?

The difference between a hard science fiction game and a space opera gameis not especially large. Both operate with a nod towardscientificprinciples, even if one takes more liberties with what might eventually be possible.Scientific rigor between settings lies on a spectrum, and what one GM considers a fundamental scientific “sin” in their hard sci-fi game, another GM might view as a necessary narrative abstraction. Often, the deciding factor is the existence of faster-than-light (FTL) technology, which usually exists only in space opera games. Exceptions, of course,can always be made.