Modern Ops / Sci-fi using D&D 5e??
I thought to myself, sure, let’s go for it. I love modern ops, sci-fi, and D&D. Why not run D&D in space? So, first, I start with how firearms and modern weapons are covered in the DMG pages 267-268 and these two articles from WOTCs website:
Modern Magic | Unearthed Arcana
Then I added my own flare for what you need in your personal setting, going with the D&D 5th Edition rule of “specific trumps general”. I also created two commonly used “paths” for the Rogue class, extrapolating from the long out-of-print “DragonStar” d20 setting.
I am a firearm instructor and range safety officer, certified by the NRA, as well as an avid handloader of ammo. But I also am a long time GM (since 1978). The rules from the two articles and the DMG are helpful, and a starting point. But I had to come up with some more realistic rules for firearm usage. However, I also had to temper those with playability. You will note that the sample weapons I have included are more or less catch-all. Some would argue with me about damage. The .308 Winchester does less damage at long range than a .300 Winchester Magnum, for example, yet I list them together. But weapon damage and usage needs to be matched to the game system play, and not to Reality. Reality says, you get shot with a .308 or a .300 Win Mag, you’re most likely dead, regardless of your Hit Points or death saves. For a FANTASY game, even a modern ops one, if we had the “if you’re hit, you’re dead” reality, it wouldn’t be much fun to play in a long term campaign situation.
I’ve included the proficiency and armor data from the WOTC articles, as modified by me, for reference, and my Rogue paths. I did not include any prices, as you’ll want to set those yourself as the DM.
I highly recommend that you incorporate the Sanity ability score from the DMG, and the Sanity check saving throw. It adds another tool that the DM can use as needed and comes in very handy at times.
New Skills
There are four added to 5E to operate in a Modern Ops / SciFi setting: Intelligence/Engineering, Wisdom/Technology, Constitution/Freefall, and Dexterity/Operations.
Engineering covers all aspects of creating, repairing, reconfiguring, and maintaining mechanical devices as complex as starships or as simple as a Chinese finger trap.
Technology covers all aspects of life in a technologically advanced society and how to correctly interact with technology, not just how it works.
Freefall is your ability to handle different gravity or lack of gravity environments, as well as gravity forces as they impact your body.
Operations covers operating devices as complex as piloting a starship to as simple as making toast in a toaster.
New Proficiencies
Side Arms — anything up to a submachine gun. Side arms are not subject to the ranged weapon penalty in melee combat.
Long Arms — anything up to a light machine gun.
Martial Arms — Using Optics, heavy machine gun, a rocket-propelled grenade launcher, flamethrower, etc.
Fixed Arms — Heavy arms that need to be fixed in place to be fired.
Certain classes may be trained in these Proficiencies. If you have characters coming from a fantasy world into the sci-fi world, like in DragonStar for example, you will want to allow them to spend downtime days or use of a feat to gain appropriate “modern” proficiencies if their class allows.
Firearm Proficiencies by Class
| Class | Firearm Proficiency |
| Bard | Side arms or Long arms (only one or the other) |
| Barbarian | Long arms |
| Cleric | Domain determined |
| Druid | None |
| Fighter | All |
| Monk | Side Arms |
| Paladin | Side arms, Long arms, Martial arms |
| Ranger | Side arms, Long arms, Martial arms |
| Rogue | Side arms or Long arms (only one or the other) |
| Sorcerer | None |
| Warlock | None |
| Wizard | None |
New Rules for Firearms
Report Shock — The report (bang) a firearm produces. When a firearm is used within 60 feet of you, you must make a DC 19 Constitution save. Failure means you are Deafened and Incapacitated. You may attempt a save at the end of your turn to end the conditions. The conditions end on their own after 1 minute has passed. The wearing of hearing protection negates the effects of Report Shock.
Ballistic damage — Ballistic damage is the type of damage that firearms and piercing ranged weapons inflict and is a subset of piercing damage. All ballistic damage counts as piercing damage, but not all piercing damage counts as ballistic damage. Magical effects or creature properties that grant resistance to piercing damage also apply to ballistic damage, but effects or properties reducing ballistic damage do not apply to piercing damage.
Aim — A character proficient with a firearm does not automatically add any proficiency bonus to the attack roll. Proficiency with a firearm allows a character to use a bonus action to take the aim action, which adds the character’s proficiency bonus to the attack roll. Without taking the aim action (or if a character is using a firearm without proficiency), the shooter receives only the benefit of a Dexterity bonus on the attack roll.
Optics — Those with the Martial Arms proficiency have advantage when they take the Aim action when using Optics. Depending on the Optics used, a minimum distance is needed to gain advantage. Within that minimum distance, use of Optics causes you to be at disadvantage. Optics have a minimum and maximum power rating expressed like 3×9. The min power of the optics times 10 is the minimum distance for the Optics use. The max times 10 is the number of feet Optics provides advantage. Max times 20 is effective range. So a 3×9 power rated scope would need to be 30 feet from the target to gain advantage, and after 90 feet loses advantage.
Suppressors — The firearm equipped with a Suppressor (also erroneously called a “Silencer”), does not produce Report Shock, and the shooter does not lose hidden status against anyone more than 15 feet away when attacking with it. Suppressors reduce the effective range to half normal. In reality, a suppressor reduces the report of a firearm only 20dB to 30dB, depending on the firearm and ammo used. Subsonic ammo is special ammo that travels less than 1116 feet per second at sea level. Unlike in the movies, you still hear the shot on most firearms, but the volume is lower than 130dB, safer for your hearing. However, when using subsonic ammo you have to be within 20 feet or so to make out it’s a firearm report. Also at that low velocity, their effective range is usually less than 100 yards for rifles like the .300 Blackout, and less than 30 feet for a pistol.
Laser Sights — Grants Advantage if within 50 feet, does not work in bright light (not to be confused with red dot / green dot Optics). In reality, green laser is more effective in bright light. The high end lasers, such as Crimson Trace and LaserMax, are more effective at greater range. At close range, even the cheap Chinese $18 laser works if sighted in properly.
Versatile — Firearms that are Versatile grant a +1 bonus, to Hit when used two-handed, instead of more damage as with normal weapons.
Sample Equipment:
M16 or AK — Long Arm, burst fire, reload (28 shots, 30 capacity), two-handed
2d8 ballistic damage, Ammunition (80/240).
Dum-dum rounds: 1d4 ballistic damage, Non-lethal, Ammunition (40/120).
Crash rounds: lighting damage, DC 21 Con save or Unconscious and one level Exhaustion, regain Consciousness upon Exhaustion removed, Non-lethal, Ammunition (20/60).
Blanks, no damage, Ammunition (0/0).
If equipped with Optics, can be used without employing them.
Remington 870 or Mossberg 500 shotgun — Long arm, reload (6 shots).
2d8 ballistic damage, Ammunition (30/90)
Pancake rounds: 2d10 bludgeoning damage, Non-lethal, Ammunition (20/60).
Sabot rounds: 2d8 ballistic damage, Ammunition (40/120).
M4 .308 or .300 Winchester Magnum sniper — Long arm, burst fire, reload (20 shots), two-handed, Optics 6×24.
2d10 ballistic damage, Ammunition (120/460)
Crash Rounds: lighting damage, DC 21 Con save or Unconscious and one level Exhaustion, regain Consciousness upon Exhaustion removed, Non-lethal, Ammunition (120/460).
GPS rounds: 1d4 ballistic damage, Ammunition (80/240).
Armor Piercing: 2d10 ballistic damage, negates ballistic resistance, Ammunition (120/460).
P90 or ISI Bullpup — Side arm, burst fire, reload (28 shots), Optics 3×9 (can be used without employing Optics), Versatile.
2d8 ballistic damage, Ammunition (60/180).
Armor Piercing: 2d8 ballistic damage, negates ballistic resistance, Ammunition (60/80).
Colt 1911 or Beretta M9 — Side arm, reload (8 shots on 1911, 15 shots on M9), Versatile.
2d6 ballistic damage, Ammunition (50/150).
Stun Wand or Taser — treat as Crash rounds: lighting damage, DC 21 Con save or Unconscious and one level Exhaustion, regain Consciousness upon Exhaustion removed, Non-lethal.
Taser: Ammunition (5/15), reload (1 shot), Versatile.
FLIR (Forward Looking Infra-Red) — Grants Dark Vision to the optics at max power rate times 20 of the optics used. Flash of bright light in optic works as Report Shock, except Blinded instead of Deafened.
Modern Armor
Light Armor
Heavy Coat — AC 11 + Dex modifier. Stealth disadvantage. Weight 6 lb.
Leather Jacket — AC 11 + Dex modifier. Weight 4 lb.
Light Undercover Shirt — AC 11 + Dex modifier. DR/2 ballistic. Weight 2 lb.
Kevlar-Lined Coat — AC 12 + Dex modifier. DR/2 ballistic. Weight 8 lb.
Undercover Vest — AC 13 + Dex modifier. DR/2 ballistic. Weight 3 lb.
Medium Armor
Concealable Vest — AC 13 + Dex modifier (max 2). DR/3 ballistic. Weight 4 lb.
Light-Duty Vest — AC 14 + Dex modifier (max 3). DR/3 ballistic. Weight 8 lb.
Tactical Vest — 15 + Dex modifier (max 2). Strength 10. Stealth disadvantage. Resistance: Ballistic. Weight 10 lb.
Heavy Armor
Special Response Vest — AC 15. Strength 10. Stealth disadvantage. Resistance: Ballistic. Weight 15 lb.
Land Warrior Armor — AC 17. Strength 13. Stealth disadvantage. DR/5 ballistic/slashing. Weight 10 lb.
Forced Entry Unit — AC 18. Strength 13. Stealth disadvantage. Resistance: piercing/slashing. Weight 20 lb.
New Archetypes
Rogue — Pilot
Defensive Maneuvering: In combat, a pilot is always maneuvering to maximize his vehicle’s defensive strengths and protect its weaknesses. At 3rd level, any vehicle or robot a pilot is operating gains a +I dodge bonus to its AC, and this bonus increases by +I every three levels thereafter (6th, 9th, 12th, 15th, and 18th).
Dogfighter: At 2nd level, a pilot gains a +1 competence bonus on ranged attack rolls as long as the attacks are made with weapons mounted on or integral to a vehicle he is piloting. This bonus increases to +2 at 9th level and +3 at 16th level. If the pilot is operating a robot remotely, he gains this bonus on all ranged attack rolls made using the robot’s weapons.
Gunner’s Instinct: At 5th level, a pilot can sense the weaknesses of his opponent’s vehicle and has an uncanny knack for scoring direct hits on them. For the pilot’s ranged attacks only, the threat range of weapons mounted on or integral to the vehicle he is piloting is increased by +10. The threat range is increased again by +10 every five levels thereafter (I0th, 15th, and 20th). The increased threat range does not apply to any attacks made by characters other than the pilot.
Pilot Evasion: At 4th level, a pilot becomes so attuned to his vehicle and to the flow of the fight around him that he is able to anticipate a hit and minimize its effects. Once per day, when the pilot’s vehicle is hit by an attack, the pilot can make a Dexterity save (DC 17). If the saving throw is successful, the pilot banks, dives, swerves, or otherwise maneuvers his vehicle sufficiently to avoid being damaged. On a failed save, the vehicle takes only half damage. On a success, the vehicle takes no damage. The pilot can use this ability twice per day at 12th level and three times per day at 20th level. If forced to make a saving throw for the vehicle, on a failed save, only half damage is taken, and no damage is taken on a success.
Speed Demon: A pilot knows how to coax out the power from his vehicles’ engines. At 1st level, the top speed of any vehicle operated by the pilot is increased by 5.
Rogue — Mechanist
New Tool Kit: Mechanist Repair kit. This kit allows a Rogue/Mechanist to repair pretty much anything, or conversely break pretty much anything, using his Intelligence/Engineering skill. It also allows him to repair Ships Avatars, Soulmechs, Warforged, Constructs, etc. for damage as a 1st level Cure Wounds clerical spell.
Favored Tech: At 2nd level, a mechanist may select a class of equipment or type of device as a favored tech. Due to his extensive training and experience operating this technology the mechanist gains Advantage to Intelligence/Engineering on or with this type of device.
At 6th level and at every four levels thereafter (I0th, 14th and 18th level), the mechanist may select an additional favored tech.
The following lists possible device classes for a mechanist’s favored techs:
• Aircraft: Fixed- and rotary-wing aircraft.
• Armor: All archaic and modem armors; includes powered armor.
• Ground vehicles: Wheeled and tracked vehicles, walkers and hovercraft.
• Electronics: All electronic devices; including computers and sensors.
• Explosives: All cxplos1ves and explosive weapons; includes grenades, missiles, torpedoes, etc.
• Handguns: All Tiny and Small firearms.
• Heavy weapons: All ranged weapons of size category Huge or greater; includes vehicle weapons.
• Machines: Miscellaneous mechanical equipment not included m another category.
• Melee weapons: All archaic and modern melee weapons.
• Rifles: All Medium-size and Large firearms.
• Robots: All robots, including soulmechs, ships avatars, warforged, etc.
• Spacecraft: All spacecraft, including starships.
• Traps: All mechanical traps.
• Watercraft: Ships and submersibles
Jury-Rig: At 1st level the mechanist can slap together spare parts and make-shift materials to manage an effective repair, even though he lacks the components or time (or both) to do the job properly. The mechanist makes an Intelligence/Engineering check as normal. If the check is successful the mechanist can improvise or scavenge sufficient spare parts and the repair takes half the time it normally would. However the device is inherently unstable; it will completely malfunction or cease operating if any of the following conditions are met:
• The device takes a critical hit in combat.
• The character wearing the device suffers a critical hit in combat.
• A character using the device for an attack or skill check rolls a 1.
Jury-rigged jobs can be redone when the mechanist has the time and parts. The mechanist must make another Intelligence/Engineering check and the task takes the standard amount of time. However, the repair is permanent, subject to the limitations of the Intelligence/Engineering skill.
Guerilla Repair: Sometimes a mechanist doesn’t even have time for a jury-rigged repair. When a gun jams in combat, it needs to be fixed now—not in a few minutes. At 1st level, mechanists can sometimes get malfunctioning devices in working order by kicking, smacking, jiggling, oiling, or even verbally coaxing them. To use this ability, as an action, the mechanist must touch the item to be repaired. In combat, this requires a touch attack if the target is unwilling. No Intelligence/Engineering check is necessary: The device will resume working properly for a number of rounds equal to 3d6 plus the mechanist’s class level. After this time has passed, the device will malfunction again. The mechanist can’t use guerilla repair on the device again until he’s done a full repair job on it. This ability cannot actually restore hit points to an object.
Sabotage: A mechanist devotes most of his time to ensuring that devices are working properly. However, he can also use his knowledge and talents to more destructive ends. At 2nd level a mechanist can use this ability as a standard action to cause any non-magic technological device he touches to malfunction. In combat, this requires a touch attack against the character or creature wearing, holding, or using the device. The mechanist selects the target device, makes the touch attack if necessary, and makes an Intelligence/Engineering check (DC 17). If the check succeeds, the device stops working. The mechanist has jammed the safety switch, poured dirt in the fuel tank, ripped out a crucial wire, or otherwise bollixed the device.
Sabotage can only be used against a single device per use. Many complex machines count as multiple devices for the purposes of this ability. For example, the mechanist could sabotage a hover tank so it couldn’t move, but its gun would still be able to fire.
Against a robot, soulmech, warforged, ships avatar, or other construct, this ability causes a d8 points “magical” force of damage for each class level of the mechanist.
This sabotage can be fixed with a normal Intelligence/Engineering check (DC 15). A mechanist can also get the device working again with his guerilla repair ability.
Upgrade: Mechanists are always tinkering with devices. Always looking for ways to make improvements to them. Starting at 1st level, a mechanist can attempt to upgrade any non-magic, technological device. The mechanist selects the device he wants to upgrade and, using the tool kit, makes Intelligence/Engineering check. If the check is successful, the mechanist may give the device a minor upgrade. The mechanist can give a device a moderate upgrade at 5th level, a major upgrade at 10th level, an extraordinary upgrade at 15th level, and a masterful upgrade at 20th level. Descriptions and examples of these upgrades are provided below.
Minor: This upgrade level makes a normal device or item the equivalent of a masterwork device or item. It provides the device with a +1 upgrade bonus on attack rolls, ability checks, or skill checks using the device. The upgrade increases the armor bonus of armor by +1, or increases the shields bonus of a starship’s shields by +1. It could be used to increase a robot’s speed by 5 feet. The exact effects and limitations of the upgrade are always at the DM’s discretion, but it should represent a minor, incremental improvement. The DC for the Intelligence/Engineering check is 17, and a minor upgrade costs the mechanist 10% of the device’s market price in materials and parts.
Moderate: As minor upgrade, except this upgrade provides a device with a +2 upgrade bonus on attack rolls, skill checks, or armor bonus. It could improve a robot’s speed by 10 feet, etc. The upgrade should represent a moderate but significant improvement. The DC for the Intelligence/Engineering check is 19, and a moderate upgrade costs the mechanist 15% of the device’s market price in materials and parts.
Major: As minor upgrade, but the upgrade bonus is +3. A robot’s speed could be upgraded by 15, etc. The DC of the Intelligence/Engineering check is 21, and a major upgrade costs the mechanist 20% of the device’s market price in materials and parts.
Extraordinary: As minor upgrade, but the upgrade bonus is +4. A robot’s speed could be upgraded by 20, etc. The DC of the Intelligence/Engineering check is 25, and an extraordinary upgrade costs the mechanist 25% of the device’s market price in materials and parts.
Masterful: As minor upgrade, but the upgrade bonus is +5. A robot’s speed could be upgraded by 25, etc. The DC of the Intelligence/Engineering check is 30, and a masterful upgrade costs the mechanist 30% of the device’s market price in material and parts.
A mechanist’s upgrades are extremely useful, but with all that tinkering things can easily go wrong. An upgraded device is a bit more delicate than it was originally, and damage or misuse can cause it to malfunction completely. An upgraded device will quit working altogether if any of the following conditions are met:
• The device takes a critical bit in combat.
• The character wearing the device suffers a critical hit in combat.
• A character using the device for an attack or skill check rolls a 1.
Devices can have more than one upgrade. Malfunctioning devices can be repaired normally, and the task is considered a simple repair. However, each additional upgrade after the first increases the DC to repair a malfunctioning device by one level. For example, the DC to repair a device with two upgrades—assuming parts and materials are available—would be 19. If the device had three upgrades, the DC would be 21.