Friday, 5 February 2016

Some Basic D&D Sci-Fi Rules

I've found another load of rules on my system, this time for a simple science fiction D&D game I had in mind. These were my system notes but I never used it - I don't even know if these rules work or not, but the starship creation rules had some promise and I might see about adapting this for D&D 5th Edition.

If anyone does use this - well, let me know if it works or not, I'm curious.



I’m a massive roleplaying fan and I was introduced to this amazing hobby way back in 1984 with the red box D&D rules. I had endless fun exploring fantasy worlds and smacking evil monsters in the face with my sword, and recently I’ve been doing it again using the rules system that got me into tabletop gaming in the first place.

In the intervening years I played well over forty different systems in just about every genre going. I’ve climbed mountains, delved into dungeons, sailed seas, patrolled the skies, ventured beyond the planet and saved entire solar systems. I’ve been a hero all over the place.

Only one genre, my favourite of them all, has stuck in my head during all these years of gaming; science fiction. I’ve always wondered what it would have been like to run a D&D-style game in a sci-fi setting. The thing is, I didn’t want to hace to klearn a new system basd on the D7D rules, I just wanted to use the D&D rules, the red box specifically, and say ‘Okay, guys – we’re in space now!’ No messing, and - more importantly – still simple to play.

So, this is what this game is all about. It’s a bolt-on for your Basic D&D ruleset, or whatever OSR ruleset you’re using. You might have to fiddle with it to suit but in general there’s nothing stopping you from simply using this with your favourite version of Basic D&D.


Basic, red box D&D was the basis for this game, but any old OSR along those lines will do. Bear in mind that the attack rolls do not use THAC0 but the roll target number of 10+AC from 3rd Edition onwards.


You can use the standard 3D6 roll for each attribute, or you can roll 4D6 and discard the lowest number. Add up the remaining three numbers and that is the score you can put in an attribute. Do this six times, once for each attribute. You can then decide which attribute receives which score based on the kind of role you want to play.

Attribute bonuses apply using the following chart:

Attribute Score             Adjustment
3                                              -3
4-5                                           -2
6-8                                           -1
9-12                                         0
13-15                                       +1
16-17                                       +2
18                                            +3

Roll 1D8 for hit points, or 1D4 + 4 if you want better odds.


STRENGTH – bonus to CQ to-hit and damage rolls
INTELLIGENCE – for each +1, choose an extra skill
WISDOM – bonus to WILL saving throw
DEXTERITY – bonus to Rng to-hit score, bonus to REFLEX saving throw
CONSTITUTION – bonus to hit point score, bonus to FORTITUDE saving throw


The saving throws 'Fortitude', 'Reflex' and 'Will' are scored at 10 plus the applicable attribute bonus. Fortitude uses the Constitution bonus, Reflex the Dexterity bonus, Will the Wisdom bonus. A successful saving throw is a D20, scoring less than the saving throw score.


Attack rolls are D20 plus the relevant Attack Bonus. Rolling high, the initial target number is 10 or the target’s Reflex saving throw for a successful hit. This is modified by armour, raising the target number, making it more difficult to hit.

The STRENGTH adjustment score modifies hand-to-hand to-hit and damage rolls.

The DEXTERITY adjustment score modifies ranged to-hit scores.

Armour class is based on normal armour in the book, so imagine the medieval equivalent in a science fiction setting. Hard leather would be a bulletproof vest or a spacesuit, chainmail a combat suit, plate full combat armour.

Weapons remain the same, use bow and crossbow damage for the pistols and such.


Each player is given three points. They can use a single point to raise an 'Attack Type', this being either Ranged (Rng) for pistols and thrown weapons or Close Quarters (CQ) for fists and hand weapons. Each point spent gives a +1 bonus to their attack roll.

Also, each point can be spent on a single skill, any type of skill they think they need, and the DM/player decides what attribute the skill falls under. Once they've decided, they get the skill at that attribute's score, and they have to roll equal to or under that score on a D20 to succeed in a skill roll; the score can be modified up or down depending on difficulty.

Some example skills and their equivalent attributes (suggested - you can change these if you wish):

Bargain – Charisma - The ability to barter, haggle and trade with other survivors. A successful roll means you get what you need for less than the asking price. This skill cannot be used on fellow PCs.

Climb – Strength - The ability to climb trees, cliffs and rubble. Difficulty depends on handholds and angle. A 45 degree angle with plenty of handholds is much easier than a 90 degree angle with very few places to grip.

Computers – Intelligence - Computers are needed for information, communication, control, all kinds of things. The difficulty modifier depends on the level of security the computer has.

Con – Charisma - Sleight of hand, misdirection and outright lies. If you want to convince someone that a lie is the truth, then this is the skill to use. This skill cannot be used on fellow PCs.

Drive – Dexterity - The ability to control ground vehicles, such as cars, motorbikes and even tanks.

Electronics – Intelligence - Need to hotwire a car or a door? Need to fix a broken radio or computer? This is the skill to use.

Engineering – Intelligence - The ability to fix a generator, a motor or a complete engine, gearbox or steering system. The Engineering Skill helps get and keep a car running.

Hide/sneak – Dexterity - A successful roll means you’ve managed to hide from those you would rather not be seen by.

Leadership – Charisma - The ability to lead people – in combat, you can direct a number of combatants equal to your Leadership skill level. If a roll is failed, the orders given are not met, such as defending a position or making it to a location in time. If rolls are consistently failed, the troops might even wander off and join another resistance group. This skill cannot be used on fellow PCs.

Leap – Strength - The ability to bound a great distance – you can jump up to two metres from a standing jump, or four metres with a run up.

Medicine – Wisdom - The ability to perform battlefield first aid. A successful roll restores 1D6 hit points using a specially formulated injection that must be slammed into the body in the right place. This skill cannot be used on characters whose Hit Points are already below 0, as they’re dead.

Perception – Intelligence - Awareness – what you notice or see around you that might be of some importance. If the GM needs to direct a player character’s attention to something then they will ask you to make this roll, or make it in private...

Persuasion – Charisma - The ability to convince someone to do, say or reveal something, either with threats or pleas. A successful roll gets one piece of information out of an NPC. This skill cannot be used on fellow PCs.

Pilot – Dexterity – the ability to pilot air- and space-based vehicles.

Science – Intelligence – choose a single field of science such physics, biology, or geology.

Survival – Constitution - Cold nights, hot days, hostile environments and dangerous weather is as much a threat as the enemy. You must roll against this skill when adverse weather strikes to successfully find shelter. If you fail to do so then you lose 1 hit point per hour the weather continues. Storms last 4D6 hours and you are allowed to re-test every 6 hours.

Swim – Dexterity - Staying afloat in water is a skill everyone needs. You can swim a distance equal to your Swim skill level multiplied by 50 in metres. After that you falter and must reach your destination rounds equal to your Swim skill or you start to tire and sink.


Characters start at level 0 and they must complete the same number of adventures for the level they want to attain. So, when they complete one adventure they go to level one. When they complete two more adventures they go to level two, when they complete three more adventures they go to level three and so on. (or, you can use the experience point system as normal).

For every level the character attains they get another single point to do ONE of the following:

-         spend on either one of the attack bonuses
-         buy a new skill at the attribute level
-         raise a skill by one point (maximum 20)
-         roll another 1D8 for more hit points.


The stats for these are decided by the vehicle’s length. For every metre in length, a vehicle or starship has 1 hit point. For every ten metres all vehicles must have at least 1 crewmember. So, a starship 50 metres in length will have 50 hit points and 5 crewmembers minimum. A car 5 metres in length will have 5 hit points and 1 crewmember (driver).

For every 1 metre in length over ten metres, a vehicle can hold 2 cubic tons of cargo. Less than 10 metres they can hold just 1 ton.

Armour class is decided by length – the smaller a vessel is the harder it is to hit. The AC is added (or subtracted) to the basic to-hit target number of 10.

Length  (metres)            AC
1-10                             8
11-30                           7
31-50                           6
51-70                           5
71-90                           4
91-100                         3
101-130                       2
131-150                       1
151-200                       0
201-250                       -1
Every extra 50m           -1 cumulative

Roll D20 higher than to-hit target of 10 + AC. If firer is using normal hand weapons (such as pistols or rifles) against the target, minus the vehicle’s current hit points score from the damage rolled (this way, handguns can’t really do any damage to huge vessels but can possible damage very small ones).

Each vessel has weapon slots. For every twenty metres in length the starship has a single weapon slot in which it can place a weapon.

Each weapon slot generates 1D8 points of damage from a single hit. So, a vessel with 3 weapon slots can fire three times and each shot does 1D8 points of damage. Each weapon must be manned individually.

However, weapon slots can be combined into a single shot and still be fired by a single crewmember. For each extra weapon slot added to the original for a single shot, add another 1D8 damage roll. So, one weapon slot does 1D8 damage, 2 combined weapon slots 2D8, 3 slots 3D8 and so on. These slots cannot be added to or removed at random – the combined feature means heavier weapons and must be chosen during creation. Pilots can fire any single weapon anywhere on the ship.

Any vehicle/starship hits on characters are multiplied by 10.

Shields – if they have them, shields give a starship a saving throw score of 10 to negate all damage. For every hit they take that absorbs the damage, the score is reduced by 1 point.

EXAMPLE: A 50 meter starship – 50 hit points, minimum crew 5, AC 6, 2 weapon slots, able to carry 100 cubic tons of cargo, shields.