In answer to discussions of what a retro-clone of the 2d6 sf game in question might look like, I present the following.

Character Creation
   Throw 2d6 for each of the following attributes: Strength, Dexterity, Endurance, Intelligence, Education, and Social Standing.  These are often written in order with letters substituting for double digit numbers.

Career Experiences
   Select a career and throw 8+ on 2d for Admission, Success, Survival, and Continue.  Admission is only rolled for the first term.  Each career has specific characteristic values which add +2 to each of the rolls if the character is greater than eight.  If the Admission roll is successful the character obtains one level in the appropriate skill for their career and continues rolling for Success, Survival, and Continuing.   If the character fails to enter their chosen career, the player may either have them submit to the draft, attend school, or live as a citizen.  Remedial Education and Advanced Education are treated as careers but provide no mustering out benefits as tuition and living expenses consume all available resources.
   Each 4 year term allows one skill to be improved by one level.  Making a Success roll provides a promotion, an additional skill, and an additional Mustering Out Benefit roll.  A failed survival roll requires a roll on the Hazard Table resulting in permanent loss of attribute points.  If an attribute falls below 0 the character dies.  The skills obtained, must be rolled for on the Personal Development, Career, or Advanced Education tables as chosen by the player.

Aging
   Characters begin their careers at 18, fresh out of primary school and by 34 they are starting to slow down.  Each term, after the third, the player must roll over Strength, Dexterity, and Endurance on two dice or lose one point from the characteristic being rolled against.  As always, falling below 0 indicates that the character has died.  If anti aging drugs are available, a 12+ Streetwise or Medical task using the character's Intelligence will allow them avoid rolling for decline for that term.  Doing so costs them one mustering out benefit.

A successful Continue roll allow the character to remain in their career for another four years.  A failed roll means they must attempt to enter a new career or muster out immediately.  If the second career roll fails they must muster out immediately.

Career (Admission, Success, Survival, Continue)
Army (Endurance, Intelligence, Endurance, Education)
Navy (Education, Social Standing, Intelligence, Education)
Marine (Endurance, Strength, Endurance, Intelligence)
Scout (Intelligence, Education, Endurance, Endurance)
Rogue (Social Standing*, Intelligence, Dexterity, Dexterity)
Scientist (Intelligence, Education, Intelligence, Education)
Barbarian (Strength, Endurance, Dexterity, Strength)
Noble (Social Standing, Education, Intelligence, Social Standing)
Merchant (Education, Intelligence, Endurance, Education)
* a Rogue receives +2 to admission if their Social Standing is less than 8.

The Draft
1   Army
2   Army
3   Army
4   Army
5   Army
6   Roll Again
   1-3   Navy
   4-5   Marines
   6   Scouts

Hazard Table (roll on failed survival)
1   -2 Strength
2   -2 Dexterity
3   -2 Endurance
4   -1 Strength and Dexterity
5   -1 Strength and Endurance
6   -1 Dexterity and Endurance

Skills
Automatic
   Computer - 0
   Small Arms - 0
   Wheeled Vehicle - 0

Personal Development
1   +1 Strength
2   +1 Dexterity
3   +1 Endurance
4   +1 Intelligence
5   +1 Education
6   Brawling

Remedial Education
(Education 7-, Intelligence, Automatic, Education 7-)
   +1 Education

Advanced Education (Requires Education 8+)
(Education 8+, Intelligence, Automatic, Education)
1   Medic   
2   Computer
3   Biology
4   Chemistry
5   Physics
6   Sociology

Citizen
(Automatic, Social Status,
1   Wheeled Vehicle
2   Tracked Vehicle
3   Computer
4   Electronics
5   Steward
6   Mechanic
Career Benefit: Automobile

Army
(Endurance, Intelligence, Endurance, Education)
Admission Skill: Rifle
Army Skills
1   Small Arms
2   Brawling
3   Tracked Vehicle
4   Survival
5   Stealth
6   Heavy Weapons
Army Officer Skills (Requires Rank 3+)
1   Leadership
2   Administration
3   Computer
4   Tracked Vehicle
5   Wheeled Vehicle
6   Aircraft

Career Benefit: Decorated

Navy
(Education, Social Standing, Intelligence, Education)
Admission Skill: Zero G Combat
Navy Skills
1   Ship's Boat
2   Engineer
3   Electronics
4   Mechanic
5   Sensors
6   Gunnery
Naval Officer Skills (Requires Rank 3+)
1   Leadership
2   Administration
3   Computer
4   Navigation
5   Engineering
6   Pilot
Career Benefit: Decorated

Marines
(Endurance, Strength, Endurance, Intelligence)
Admission Skill: Cutlass
Marine Skills
1   Battle Dress
2   Heavy Weapons
3   Gunnery
4   Zero G Combat
5   Cutlass
6   Small Arms
Marine Officer Skills (Requires Rank 3+)
1   Leadership
2   Administration
3   Computer
4   Sensors
5   Gunner
6   Ship's Boat
Career Benefit: Decorated

Scout
(Intelligence, Education, Endurance, Endurance)
Admission Skill: Pilot
Scout Skills
1   Survival
2   Sensors
3   Survey
4   Riding
5   Navigation
6   Grav Vehicle
Scout Official Skills (Requires Rank 3+)
1   Administration
2   Leadership
3   Pilot
4   Sociology
5   Computer
6   Biology
Career Benefit: Ship Share

Rogue
(Social Standing*, Intelligence, Dexterity, Dexterity)
Admission Skill: Street Wise

Rogue Skills
1   Street Wise
2   Intrusion
3   Gambling
4   Administration
5   Stealth
6   Bribery

Scientist
(Intelligence, Education, Intelligence, Education)
Admission Skills: Biology, Chemistry, or Physics
Scientist Skills
1   Medical
2   Biology
3   Chemistry
4   Physics
5   Sensors
6   Survey
Scientist Authority (Requires Rank 3+)
1   Administration
2   Computer
3   Merchant
4   Electronics
5   Mechanic
6   Sociology
Career Benefit: Endowment

Barbarian
(Strength, Endurance, Dexterity, Strength)
Admission Skill: Survival
Barbarian Skills
1   Melee Weapon
2   Bow
3   Survival
4   +1 Strength
5   Craftsman
6   Stealth
Barbarian Warlord Skills (Requires Rank 3+)
1   Leadership
2   Chariot
3   Sailing
4   Riding
5   Merchant
6   +1 Social Standing
Career Benefit: 1d6 Cattle or Equivalents

Bureaucrat
(Social Standing, Education, Intelligence, Social Standing)
Admission Skill: Administration
Noble Skills
1   Administration
2   Bribery
3   Sociology
4   Computer
5   Air Raft
6   Streetwise
Noble Skills (Requires Social Standing 12+)
1   Melee Weapon
2   Riding
3   Gambling
4   Leadership
5   Navigation
6   Pilot
Career Benefit: 100 000 Credits

Merchant
(Education, Intelligence, Endurance, Education)
Admission: Steward
1   Merchant
2   Grav Vehicle
3   Administration
4   Steward
5   Electronics
6   Mechanic
Merchant Officer Skills (Requires Rank 3+)
1   Sensors
2   Sociology
3   Medic
4   Engineer
5   Ship's Boat
6   Pilot
Career Benefit: Ship Share

Mustering Out
   Once a character has failed a Continue roll, you find out what they got for all their trouble.  Roll once per four year term and once per success.  If the character has used anti-aging drugs they automatically lose one benefit.  Each career has a specific career benefit which is obtained should that result be rolled.  These are discussed below.

1   1000 Cr
2   +1 Edu
3   10000 Credits
4   Contact
5   Career Benefit
6   Pension

Cattle and similar herd animals are very valuable in primitive societies as they can be eaten and carry themselves from place to place, things which gold and jewels will never do.

Contacts are non player characters that are friends or owe favors.  At any time in play a contact can be activated to help the player in their time of need, no matter how outrageous it may seem that they have a friend living in a deadly alien jungle at just that moment.  Once a contact is used they are fixed to that location and depending on the risks and costs involved it is safe to assume any debt of gratitude has been fully repaid.

Decorated provides an honorary promotion on the first receipt, +1 Social Standing on the second, and a Ship Share on any subsequent occurances.

Endowments are grants for continuing work providing 50000 Credits per year as long as the scientist continues to publish.  In exchange, the endowing government or corporation owns the patents on any resulting discoveries.

A pension pays 500 Credits per month for the rest of the character's life.  

Ship shares are valued at 10 Mega Credits each when purchasing a ship and can be sold off for 1d6 x 100000 Credits each.  At least 20% of the ship's actual value must be available at the time of purchase and the payments are 5% of the ship's total value per month until it is paid off.

Combat
   Physical altercations are nasty and undesirable and thus need to be resolved as quickly and pleasantly as possible.  Each combatant selects a target and rolls an attack roll using the skill appropriate to the weapon they use, they can all do this at the same time.  If the attack roll is successful, they hit their target and inflict the damage appropriate to their weapon.  Damage is applied simultaneously, however, ambushed parties do not get to attack in the first turn.

Sequential Exceptions
   Those with shorter ranged weapons must close the range to attack and will often need to move in order to get into range, meaning they will not attack for a number of rounds.  At Long range or less they can charge into combat in a single round but will attack after all shooting and attacks by those with longer melee weapons have taken their turn.

Movement
   It is possible to move between close, short, and medium ranges while making an attack.  Moving to or from Long range to any other range takes a full turn during which no attacks can be made.  Moving from Very Long range to Long range takes a full turn as well.

Vehicles In Surface Combat
   Generally, vehicles are fast enough to move to any position and attack.  However, they are often moving so fast that they overshoot the target.  Aircraft with stall speeds are particularly prone to overshooting their mark as they have a significant minimum speed.  Since attacks can be made while overshooting and will leave the vehicle at a safer range next turn at which it can turn around and make another round.  Outmaneuvering another vehicle can be difficult but will prevent it from using fixed mount weapons to attack you.

Attack Run 8+
   + Vehicle Skill

   -2 Outmaneuver Faster Vehicle
   - Target’s Vehicle Skill to Outmaneuver
   -2 Outmanuver Higher Dexterity Pilot
   -2 Engage Target At Medium Range
   -4 Engage Target At Short Range
   -6 Engage Target at Close Range
   +2 Dexterity > Final Target Number

Disengaging and Chases
At times, one side will want to open the distance while the other wants to close. It is a simple matter when speeds and terrain are relatively equal as the range stays the same. If one side is significantly faster than the other they get to choose the range as such, supersonic aircraft have the advantage over subsonic aircraft which have the advantage over hovercraft and wing in ground craft which have the advantage over ground vehicles which have the advantage over mounted troops which have the advantage over the poor bloody infantry. Pursuit and evasion can be handled with a task roll for either side, usually the player characters.

Pursue or Evade 8+
Active Party's Vehicle Skill
-2 to evade over open ground
+2 to pursue over open ground
+2 faster
-2 to pursue through dense terrain
+2 to evade through dense terrain
-2 target has higher Dexterity
+2 Dexterity > Final Target Number

Making Range Bands Work For You
   Given the abstract nature of combat, keeping a clear view of who is where can get confusing in larger combats.  A simple sketch map and some letters to mark positions can be very helpful.  Providing a description of what lies in each direction can be very helpful.  For instance, “You are on a loading dock littered with barrels and boxes, there is a warehouse at short range behind you, and a diner at short range to your left.  To the right there is a parking lot with a couple ground cars and an air / raft. there is a road at short range ahead of you that runs in each direction into the distance.  Beyond the road, and separated by a chain-link fence, at long range  is an open field.  At very long range, past the field and another fence are some low hills covered in scrub.”  Sketching this out and showing movement with arrows will make the situation even clearer.

Ammunition and Reloading
   It is safe to say that single shot weapons will not run out of ammunition under normal circumstances.  Rapid and Very Rapid fire weapons and single shot weapons are another matter.  If ammunition is in short supply, matters are worse.  For the sake of avoiding book keeping any natural attack roll less than the number listed on the table below indicates the weapon is out of ammo.  The second number is used if the unit is out of supply and short on ammo.  In the long term, an out of supply unit cannot use weapons that run out of ammo until they are re-supplied.

Out of Ammo Roll / Out of Supply
Single Shot 8 / 10   
Normal 2 / 4
Rapid Fire 4 / 6
Very Rapid Fire 6 / 8

Ranged Attack 8+
   Requires Line of Sight and In Range
   +2 Dexterity > Final Target Number
   + Small Arms, Bow, or Heavy Weapons Skill
   -2 Maximum Range Band
   -2 Darkness (unless electronic sights)
   +/- Target Size
   +2 Telescopic Sight
   Rapid Fire +2 or Attack Close Group
   Very Rapid Fire +2 and Attack Close Group

Melee Attack 8+
   Requires Close Range
   +2 Strength > Final Target Number
   -2 Target’s Dexterity > Attacker’s Dexterity
   + Melee Weapon Skill or Brawling
   - Target’s Melee Weapon Skill or Brawling
   -2 Darkness

Critical Hits
   A natural attack roll of 12 inflicts +1 damage per die.

Group Hits
   Some weapons spray an area with bullets, beams, or fragments.  In such a case roll an attack against anything within the specified range from the target.

Detection and Thus Encounter Range
Terrain   Range   
Urban       Short
Plains       Very Long
Mountains    Long
Hills       Medium
Woods    Short
Jungle    Short
Swamp    Medium

Lay Ambush 8+
   requires detecting enemy first
   -4 Enemy Has Infrared Sensors
   + Stealth Skill
   +2 Camouflage
   + 2 Dexterity > Final Target Number
Laying a successful ambush allows the attackers to choose the starting range for the encounter and make a full round of attacks without facing return fire.

Melee Weapons
Brawling    0.5d    Short Reach
Dagger    1d6    Short Reach
Blade       1.5d
Spear     2.5d    Long Reach
Sword    2d
Broad Sword    3d
Halberd    3d    Long Reach

Claws       1d    2 Attacks    Short Reach
Teeth       2d     Short Reach
Horns       3d    
Thrasher    3d    Short Reach

Missile Weapons
-1 damage per die damage at Maximum Range
HE Grenade    4d    Short    Hits Close Group
Sling    1d   100m    Medium
Bow    1.5d   200m    Medium
Body Pistol    1.5d    Medium
Auto Pistol    2d    Long
Revolver    3d    Long
SMG       2.5d    Long       RF
Carbine    3d    Very Long
Rifle       4d    Very Long
Auto Rifle    4d    Very Long    RF
Shotgun    4d    Long       Hits Close Group
Machine Gun    4d    Very Long    VRF

Snub HEAT   4d   Short
Snub HE   3d   Short    Hits Close Group

Laser Pistol   3d   Long
Laser Carbine   3d   Very Long    RF
Laser Rifle   4d   Very Long    RF

Gauss Pistol   2d   Long    RF
Gauss Rifle   3d   Very Long    RF
Gauss Gun   4d   Very Long    VRF

Plasma Gun   5d   Medium    Hits Close Group
Fusion Gun   6d   Long        Hits Close Group

RAM HEAP   6d   Long
RAM HE   4d   Long       Hits Short Group

LAW      6d   Medium
Mortar   4d   Very Long    Hits Short Group

Applying Damage
   Damage is applied to the target’s attributes, one dice at a time, always starting with the highest attribute.  Armor is treated as an additional attribute and absorbs a fixed amount of damage before being destroyed.  If one attribute is reduced to zero the combatant is rendered unconscious.  If two are reduced to zero they are in critical condition.  If all three attributes are reduced to zero they are killed.

Personal Armor
Cloth      6
Mesh      9
Plate      12
Flak      9
Ballistic   15
Combat   18

Cover
   Hiding behind something hard is a great tactic but it’s not fool proof.  If you aren’t attacking, cover also counts as concealment, usually preventing the attacker from obtaining line of sight.  Infrared sights and sensors can almost always target you right through cover and concealment.  Cover has an armor rating which is always attacked before attributes.  Many weapons will make a joke out of soft cover so it doesn’t make sense to treat armor as a to hit penalty.  Cover can be destroyed but there’s usually more of it right next to the big hole.

Dirt   6
Wood   4
Stone   8
Concrete 6
Metal   10

Space Ships, Robots, and Vehicles
   All of these things run on the same rules.  A robot is designed and operates like a small autonomous vehicle and a space ship is a really big vehicle.

Size and Volume
   In naval parlance, a displacement tonne is the volume displaced by one ton of water.  It’s convenient that this equates to one cubic metre.  Less convenient is the futuristic conceit of measuring the volume of vessels in tonnes of hydrogen displaced.  So, for the sake of simplicity a displacement “ton’ is considered to be 14 cubic metres of hydrogen.  It’s been rounded off for the sake of simplicity but really we’re going to largely ignore it and work in cubic metres and make some big assumptions about consistent density.  So, if you want to build a “1000 ton” ship it’ll be 14 000 cubic metres but that’s okay because we’re mostly going to use volume to find how many state rooms fit in a given space and use percentages of the ship’s volume for everything else.  Call me lazy, call me crazy, but it seems to be the most sensible way to approach things.  The main thing to keep in mind is that all ships have a maximum volume of 100% of their volume.

Structural Considerations
   As surface area increases at the square of the cube root of volume and structural requirements increase at the cube of the square root of volume we’re just going to be lazy and pretend that they mostly cancel out.  The one exception would be in terms of really large or really high acceleration vehicles in which case high tech inertial dampening technology is probably going to be required to build that megametre long dreadnaught.

Basic Structures
   Vehicles that are to operate in a hospitable atmosphere need only devote 2.5% of their volume to structure.  If the vehicle needs to accelerate at more that 1 G the volume must be multiplied by the desired acceleration.  Doing so also increases the vehicle’s ability to withstand pressure.

Sealed Structures
   The air-locks and locking air-tight hatches needed to make a vehicle space worthy take up 5% of the vehicle’s total volume.  This includes air circulation and recycling systems to make it self sufficient without resupply.  If the vehicle needs to withstand greater pressures, multiply the base volume by the atmospheres of pressure to be withstood this is the same multiplier as the acceleration requirement.   

Robotic Structures
   A fully autonomous vehicle or robot will require twice the normal portion of its volume to be dedicated to structural concerns.

Armored Structures
   Protecting the vehicle from attacks increases its structural requirements as well.  Multiply the structural volume by any number and the integrity of the systems by the same number.

Integral Power Systems
   It’s a given that any powered hull has sufficient integral energy and fuel to power any lights, computers, doors, air locks, air recyclers and similar fundamental systems whether the main power plant is working or not.

Aerodynamic Structures
   If a vehicle needs to fly using aerostatic lift, the wings and fins take up 25% of its structure.  On the other hand, such vehicles are pretty light weight and double their acceleration.  An airframe has a stall speed which needs to be exceeded to generate lift in order to climb.  This is generally 100 kilometers per hour but can be increased or decreased by increasing or decreasing the airframe proportionately.  So a 50% air fame triplane has a stall speed of 50 kilometers per hour.

Suspensions
   Ground vehicles can take advantage of friction to aid their acceleration and thus need no reaction mass.

Wheeled
   A wheeled suspension intended for road use takes up 5% of the vehicle.  An off road suspension takes 10%.  A transmission that transfers power or torque from the power plant doubles that.   Retractable wheels take twice that and are commonly found on aircraft that need a take off run.  

Tracked
   A powered, heavy crawler suspension takes up 20% of the vehicle and can maneuver across broken ground.  

Legged
   A powered walking vehicle suspension takes up 30% of the vehicle and can maneuver in broken ground.

Drives
   The various engines that are used to move ships around in space at slower than light speeds vary a great deal from one setting to the next.  To help in running a variety of settings a number of these are discussed here.  All of these drives are a bit exaggerated relative to what is probably possible in the real world but they produce specific effects in play that make the game interesting.

Ion Drives
   These drives output a very small amount of reaction mass at low velocities to produce long term constant acceleration.  An Ion Drive requires 50% of the vehicle to achieve a single G of acceleration but needs only 10% of the vehicle’s volume per 10G / hours of acceleration.

Rocket Drives and Jets
   A rocket fires reaction mass at high speeds to produce short term acceleration.  A Rocket requires 5% of the vehicle  to accelerate at 1 G but uses 10% of the vehicle per G/hour of acceleration.  Rockets do not require support from a power plant to fire.  A jet uses the air ahead of it as reaction mass so it uses half as much fuel but cannot provide acceleration beyond the atmosphere.

Thrusters
   A reactionless thruster bends gravity waves to propel the vehicle forward.  A gravitic thruster requires 5% of the vehicle to accelerate at 1 G and uses no reaction mass.  However, it requires a power plant output equal to its volume.  Thrusters require more and more power as they reach relativistic velocities and thus have a maximum speed of around 1000 times their maximum acceleration.

Anti-Gravity
   The main reason space travel is difficult and expensive is that escaping a planet’s gravity well takes a great deal of acceleration and fuel and sealed compartments and life support systems just make the vessel heavier and more expensive to get off planet.  If you want space travel to be common place it’s a good idea to allow anti-gravity systems.  Such a system requires 5% of the vehicle’s total volume and requires an equal amount of power.

Hyperdrives
   A hyperdrive moves the vessel out of three dimensional space into another dimension where it can move faster than light or perhaps one where light moves faster.  In any case it’s gone until it comes back out.  A hyper drive takes up 5% of a vehicle’s volume per parsec / week and needs power equal to its volume.  A hyperdrive equipped vehicle needs a maneuver drive of some sort but can share the power plant as only one needs to be operational at a time.  Some smugglers and pirates like to be able to jump and run and will want the larger power plant so they don’t have to cut the thrusters to power the hyperdrive.

Jump Drive
   A jump drive is a hyperdrive that always takes a week to get anywhere regardless of the distance jumped.  They require only 3% of the vehicle’s volume per parsec / week but requires 10% of the vehicle’s volume in fuel per parsec to make the jump.  Jump drives are particularly useful in games with a tight turn sequence because they cut down on record keeping and provide a natural turn length of one week.

Warp Drive
   A warp drive moves the vehicle through real space by distorting space time in front of it.  This generally requires faster than light sensors and force fields as running into stuff at such speeds is disastrous.

Power Plants
   It’s assumed that the standard power plant system will be a hydrogen + hydrogen = helium fusion system similar to those we call stars.  It’s a hot source that supplies lots of power for not too much fuel.  Ion Drives, Thrusters, Hyperdrives, and Warp Drives all require a power plant of equal size to power them.

Fission Reactors
   A fission reactor generates power by breaking heavy elements down into lighter ones.  It’s easier than fusion but not really safer as they generate significant amounts of lethal radiation.  Fission reactors are essentially a lower tech option with drawbacks.  But they are usually much heavier, producing only half as much power as a Fusion reactor.

Antimatter Reactors
   Antimatter / matter annihilation is a high energy source that uses the most dangerous fuel imaginable.  If you can use the stuff for power, you can use it for weapons and it’s as dirty as fission, more powerful than fusion, and about as easy to handle as nitroglycerine.  It doesn’t seem to occur naturally in the universe even though our understanding of the math implies it should make up about half of the matter in the universe.  The power output of an antimatter plant is double that of a fusion plant.  The fuel is usually kept in pods mounted on spars to allow them to be jettisoned at a moment’s notice.

Fuel Cells
   The chemical reaction that produces water is a good, clean, consistent, low power source that is often used in vehicles that work in habitable areas.  A because it is simple and clean, a fuel cell system produces power equal to a fusion reactor of the same size but requires fuel equal to its volume every day to operate.

Batteries and Power Cells
   Energy storage banks need no fuel but require recharging.  They only produce half the energy a fusion plant would and only run for a day.

Crew Requirements
   At the bare minimum a vehicle only needs one crew person to pilot it.  However, a vehicle that runs non-stop will need three pilots on eight hour shifts.  Most ships will carry a full maintenance crew, a gunner for each weapon mount, and three full shifts of navigators and sensor operators.  This works out to 12 + 1 / 100 cubic metres of drives and power plants.

Quarters and Crew Stations
   Allow 1 cubic metre for each crew work station and 20 - 30 for each stateroom.  28 is awfully convenient if you’re using hundreds of displacement tons.  Crew can double bunk in state rooms or even hot bunk in three shifts if necessary in tight quarters.  Staterooms are assumed to allow for sanitary facilities though these are usually separate from the actual rooms.

Gravity Plates and Inertial Dampers
Ships are often fitted with gravitic field generating plates in the floor to provide gravity. An outgrowth of this technology is used to manipulate inertia to reduce the impact of high G maneuvers and structural strain. Gravity plates consume 1% of a vehicle's volume and require an equal volume of power plant to support them. Inertial Dampers are an advanced variety of gravity plates which increase the g tolerance of the ship's crew and hull by three.

Weapon Mounts
   Due to limited surface area and structural (not to mention game mechanical) restraints, weapon mounts can take up no more than 1% of a vehicle’s total volume.  Fixed weapon mounts can only fire in one direction and can only be aimed and fired by the pilot.  Turrets take up twice the mounted weapon’s volume.  A standard turret is a 14 cubic metre installation that can mount three standard 2 cubic metre weapons and contains a 1 cubic metre crew station.

Vehicle Tubes and Bays
   Ships carry boats.  That’s what makes them ships.  A bay can accommodate any vehicle half its size, seventy five percent in the case of boxy wheeled and tracked vehicles.  A custom tube or slot only needs to be 10% larger than the vehicle it holds but can only hold other vehicles less than half that size.

Simple 2800 cubic metre Trader
Sealed Structure 140 cubic metres
Anti Gravity 140 cubic metres
1 G Thrusters 140 cubic metres
1 P Jump 84 cubic metres
Fuel 280 cubic metres
Fusion Plant 280 cubic metres
2 Standard Turret Sockets 28 cubic metres
10 State Rooms 280 cubic meters
4 Crew Stations 4 cubic meters
Cargo Bay 1424 cubic meters

Vehicle Damage
   Linear math is simple but it gets weird in games with limited scope.  The target size scale is in factors of ten.  So 1cubic meter +1, 10 cubic meters +2, 100 cubic meters +3 and so forth.  I think multiplying that by the furthest digits to the left is pretty simple, maybe a chart with a smooth progression and decimals.  Gives our Trader 112 damage points.  I dunno, I’ll have to think about that one.  1, 2, 3,5, 7 ?  Weapon damage multipliers would need to scale at roughly the same rate of course.  What happens when you fire a man portable fusion gun at a Simple Trader, that’s what I’d like to know.

Generating Worlds
   Every star has a variety of debris, micro meteors, asteroids, and planetoids floating around it.  Older stars and larger stars gravity fields will sweep out more of them but there will always be plenty of stray navigational hazards.  In the main adventurers will be interested in rocks that are large enough to have sufficient gravity to hold an atmosphere down and in the “goldilocks zone” where liquid water exists.  With a little luck there will be some life forms to convert carbon dioxide into oxygen and produce a breathable atmosphere and some more advanced life forms to trade with.  For these reasons, only inhabited worlds need to be generated and these rules favor inhabited worlds.

Size      2d6 - 2 (x 1.6 Kilometres diameter)
Atmosphere   Size + 2d6 - 7 (lower is thinner, higher denser)
Water      Atmosphere + 2d6 - 7 (percentage of surface)
Population   2d6-2 (10 to the power of Population roll people)
Government   Population + 2d6 - 7
Law      Government +2d6 - 7

Size indicates the diameter of the world.  Multiply it by 1600 to find the diameter in kilometers.  Size also indicates the world’s gravity with 7 being 1G and each point away from that reducing it by 10%.

Atmosphere primarily indicates density with 7 being average.  Odd numbers contain taints, pollutants, and at high levels actual toxins that make it unbreathable.

Water indicates the percentage of the planet’s surface that is covered in water.

Population levels indicate increases by factors of ten.  A second 2d6-2 roll can be used to find a multiplier if more detail is desired but is not reference in the game mechanics.

Government indicates the complexity and repressiveness of the social order with higher rolls indicating a more oppressive and unmanageable government.  A world’s Government rating acts as the target number for Administration tasks like getting an exit visa while a ship is berthed there.   While it is possible to assign terms like “democracy” and “dictatorship” to governments these are vague labels at best.

Law Level indicates what weapons can be carried and how restrictive legal barriers to trade are.

0   No Restrictions
1   Large Group Attack Weapons
2   Medium Group Attack Weapons
3   Very Rapid Fire Weapons
4   Short Group Attack Weapons
5   Rapid Fire Weapons
6   Pistols
7   Rifles
8   Long Melee Weapons
9   Medium Melee Weapons
10   Short Weapons
11   All Weapons

Star Port
   The quality of facilities can be determined by rolling 2d6-2 on the following table

0   No Facilities
1   Cleared Area
2   Landing Strip
3   Landing Strip and Fuel
4   Landing Strip, Fuel, and Hangers
5   Landing Pads, Fuel, Hangers, and Hotels
6   Docking Station and Down Port
7   Orbital Port and Shuttle Service, One Down Port
8   Orbital Port,City, and Shuttle Service, 2d6 Down Ports
9   Ship Yards, Orbital City, and Shuttle service, 3d6 Down Ports
10    Off World Colonies, Orbital Cities, Numerous Down Ports
   
Tech Level
If a variable Tech Level is desired roll 1d6 + Star Port - 3, +1 for any other characteristic below 2 or over 10, as they would make life without high technology unsustainable.

Tech Levels determine the availability of equipment and ships systems.

0   Stone Tools and Weapons, Agriculture, Domestic Animals
1   Bronze Tools and Weapons, Stone Buildings
2   Steel Tools and Weapons, Water Wheel Power
3   Black Powder Firearms
4   Cartridge Repeaters, Steam Engines   
5   Machine Guns, Internal Combustion Engines, Aeroplanes
6   Radar, Pressurized Aeroplane Cabins
7   Early Computers, Satellites, Guided Missiles, Fission Power
8   World Wide Computer Networks, Stealth Aircraft
9   Laser Weapons, Anti Gravity, Jump Drive 1
10   Thrusters, Grav Plates, Fusion Power
11   Jump Drive 2
12   Jump Drive 3
13   Inertial Dampers, Jump Drive 4
14   Jump Drive 5
15   Jump Drive 6

Sigged, even though the forum format kind of makes it a pain to read.

Right now it doesn't look much better in my word processor.  I'm just dumping out information as I get to it.

My goal is a game that includes robots, vehicles, and ships in the core and maintains a pretty tight page count.  I haven't even started to implement tech levels though they'll mostly exist in terms of availability rather than upgrades.

I want a very straight forward and non-fiddly game.

Quote from: David Johansen;924401I want a very straight forward and non-fiddly game.

Dragon-Shadowed Lands is the only version of RM I'd play. I'm familiar with your MO

I have a hard time with the assumptions of the combat system not making sense to me. (Maybe I shouldn't comment because I am not going to want to put the time and attention needed into trying to explain and go through details, and I already would "just use GURPS or something" that does have the elements I'd want. When I played Traveller 30 years ago, I had to fill in with house rules and borrow from TFT and Squad Leader rules etc. before things made any sense to me.)

My sticking points include:

* The range bands and movement rules seem far too abstract to me, especially about being able to just close the range AND attack, without any rules about denying that, the situation / terrain, modifiers to attacking and moving at the same time.  To me, combat is all about the situation and what you choose to do with it, and there are so few rules for any of that... so it'd be up to the GM to just judge the combat system, and/or the players to converse with the GM about what they do and what effects it should have, or no one would do any of that and it would just be an abstract damage exchange.

* If someone can move and attack with no penalty to close the range, why can't an enemy also move and attack to keep the range where it is (assuming they can move at the same speed and there are no obstacles)?

* The lack of ways to avoid getting killed, except armor and cover, the values for which seem pretty weird and unsatisfying to me. Again, especially with guns, I think combat is mainly about avoiding getting killed, and so the situation and what you do in that situation is what determines whether you live or die, and most of that is not represented at all in this system.

* The simultaneous damage thing... increases the helpless damage exchange nature of the combat. In some situations it could be appropriate, but not all, and I'd think skillful play would be about avoiding those situations... so ya, avoiding being in combat altogether, given that the combat system provides little/no way to do that, other than surprising or out-ranging enemies and doing enough damage to eliminate them before they get in range.

* The abstract ammo rules seem weird/off/silly in various ways.

* "Vehicles in surface combat" seems to be trying to abstract everything into one mechanic that seems to be about 20th Century airplanes with fixed guns, which also sounds a bit like it is thinking about non-simultaneous turn-based movement, which mainly comes off as weird to me.

So, simultaneous combat is from Classic Traveller as are the range bands.  The thing simultaneous attacks avoids is the side with the initiative wiping out the opposition before they can even shoot.  You're right that one option should be to move away and keep the range open, it's called withdrawing.  I'm not really a fan of abstract ammo, it's in T5 but yeah never really happy with it but I want combat to work for sizable exchanges and I want a fixed limit on the overuse of some heavy weapons, otherwise they're all anyone will ever take.  I need to write some discussion of using more concrete movement.  There probably need to be some to hit penalties for flyby's over closing in slowly.  As far avoiding getting killed, I'm afraid cover, concealment, and armor are it.  The numbers are quite possibly off a bit but how much protection does a leather vest provide against a plasma blast?

Not to worry, it's a work in progress and feedback really helps.  The problem is staying within the range of still being Traveller.  I actually have two non-Traveller sfrpgs but this particular project is closer to Dark Passages than Dragon Shadowed Lands (thanks for the kind words btw).  It's a restatement of a classic that tries to slip in a few patches.  I thought about using MegaTraveller's damage system but it's a bit cluttered and still doesn't work for ships.

Okay, so here's some addenda that I'm also adding to the main body of the text.

Disengaging and Chases
At times, one side will want to open the distance while the other wants to close.  It is a simple matter when speeds and terrain are relatively equal as the range stays the same.  If one side is significantly faster than the other they get to choose the range as such, supersonic aircraft have the advantage over subsonic aircraft which have the advantage over hovercraft and wing in ground craft which have the advantage over ground vehicles which have the advantage over mounted troops which have the advantage over the poor bloody infantry.  Pursuit and evasion can be handled with a task roll for either side, usually the player characters.

Pursue or Evade 8+
Active Party's Vehicle Skill
-2 to evade over open ground
+2 to pursue over open ground
+2 faster
-2 to pursue through dense terrain
+2 to evade through dense terrain
-2 target has higher Dexerity
+2 Dexterity > Final Target Number

Gravity Plates and Inertial Dampers
Ships are often fitted with gravitic field generating plates in the floor to provide gravity.  An outgrowth of this technology is used to manipulate inertia to reduce the impact of high G maneuvers and structural strain.  Gravity plates consume 1% of a vehicle's volume and require an equal volume of power plant to support them.  Inertial Dampers are an advanced variety of gravity plates which increase the g tolerance of the ship's crew and hull by three.

Character Creation Example
Attributes:
Strength 5 + 3 = 8
Dexterity 3 + 1 = 4
Endurance 4 + 1 = 5
Intelligence 3 + 4 = 7
Education 6 + 1 = 7
Social Standing 6 + 6 = 12

Term 1
Entry (7 + 2 Social Standing 12)
Success (8 no bonus for Education 7)
 Administration -1
Melee Weapon -1
Gambling -1
Continue (6 +2 Social Standing 12)

Term 2
Failure (4 No Bonus for Education 7)
Riding -1
Continue (9 + 2 for Social Standing 12)

Term 3
Success (6 +2 for Social Standing 12)
Gambling - 2
Pilot -1
Administration -2
Continue
Failed To Continue (4 +2 for Social Standing)

Mustering Out
3 terms + 3 Successes = 5
3 10000 Credits
5 100000 Credits (Career Benefit)
4 Contact
5 Pension

   Jarius 84577C 3 Terms Noble, Age 30
   Gun Combat - 0, Wheeled Vehicle - 0, Administration -2, Melee Weapon -1, Riding -1, Gambling -2, Pilot -1

120000 Credits, Pension, Contact

I'll probably get around to building out the mustering out table for each career before I'm done.  I'm not sure if I'll do the cash table / benefits table split.  Personally, blank mustering out spaces are way too hard on young characters.

Yep I remember questioning/modding the simultaneous combat and range options when I briefly GM'd original Traveller.

I realize you're just trying to make a nice elegant clone of the basic Traveller rules. I'm just sharing from my own perspective, which is pretty extreme in terms of wanting interesting detailed combat, but I think I might have some ideas that might be helpful, so...

Here are a few ideas/suggestions:

* Simultaneous combat works ok in chaotic abstract battles where it's considered out of scope whether anyone knows what is going on or is using any particular tactics. It works best when to-hit chances are relatively low, and players are not getting overly gamey in how they target enemies. It becomes a crucial issue (if you care who dies) how much coordination fighters are allowed to do, and whether they get to observe results before picking the next target. i.e. are you allowed to just target one enemy at a time, going from most to least value of taking them out per shot, and stop targeting each enemy as soon as you see it's dead? Because that can seem really gamey quickly in many situations. More fair/interesting/unpredictable/realistic would be to require all targets to be declared before rolling results. Also most real situations would present some limits on how many people on one side have opportunity to see/target each enemy, unless each target is really wide open to every foe.

* If there are few enough enemies that it's not too much work, interleaving actions between sides tends to work better, especially for close combat where to-hit chances are high and shooting first should matter. We had characters on both sides act in order of speed calculated as DX minus penalties for armor, slower weapons (we gave pistols +1 speed over rifles), or circumstances (injury, moving while firing, taking time to aim, etc).

* I love combat that uses maps. With deadly ranged weapons, if you play with maps you realize how important terrain and movement and facing are. Who gets to shoot whom generally has mostly to do with maneuver and awareness and terrain, because it's almost impossible to hit anyone if you don't see where they are, and walls and hills and even grass tend to mostly block most vision for most targets at much shorter than the theoretical effective range of weapons. Even with magic sensors, you may need to identify enemies, or target them other than calling in fire support by clicking on a smart phone. Having played such situations, just having range bands and being able to target whoever just feels like it's only appropriate for people all stuck in a wide-open area suddenly becoming hostile. Stepping around the corner of a building, for example, will/should make someone unavailable to be targeted until/unless someone has line of sight or something. If you've got a map, an interesting game emerges that is about the map, even if you just have some basic rules for line of sight/fire, movement, and taking cover and spotting/facing.

* The cover and armor values look weird to me. Plate armor that you have to wear is the same thing as taking cover behind something that may be a major terrain feature of building made of stone or metal? Consider that in real combat, trained people will take the best cover available and fire until fired upon, at which point they may roll well out of the way until the fire stops. That doesn't really match an "add some armor" mechanic to me.

* For chases and trying to keep the range open, again I think it helps to get more detailed and to have a map to chase over. Again, the outcome if you play it out in detail would have a lot to do with the terrain and movements taken, as well as the nature of the equipment used. A tank CAN turn its turret around to fire backwards while driving away, but that exposes rear armor. Running and firing with guns is possible but is generally very very inaccurate. Being under fire while moving quickly can be dangerous. Just standing up in the open as opposed to lying low and taking cover and shooting carefully is generally extremely dangerous if you are exposed to enemy gunfire and don't have some circumstance to help keep you alive, such as friendly covering fire, smoke, or something keeping the enemy from shooting you in the open.

* Different detail levels can be used for PCs and major NPCs, particularly for ammo levels. PCs can track bullets or bursts, and heavy weapons should probably track rounds where appropriate, to avoid the "let's see if we luck out and have more ammo for the bazooka, which we can't know until we fire it" weirdness.

I'm a miniatures guy so I hear you.

The thing about cover as written is that it only takes effect if you're shooting.  If you're concealed you're harder to hit and protected.  The real issue is the thickness of cover which I should put in something like +3 if 10 cm to 20 cm, +6 if 20 cm - 30 cm etc.

I've already got two map simulation rule sets so I didn't go there.  Really, this is just a stray idea that ran away with me.  I need to hurry up and finish it as I'll probably be hearing from the lawyers pretty soon

Tech Levels determine the availability of equipment and ships systems.

0   Stone Tools and Weapons, Agriculture, Domestic Animals
1   Bronze Tools and Weapons, Stone Buildings
2   Steel Tools and Weapons, Water Wheel Power
3   Black Powder Firearms
4   Cartridge Repeaters, Steam Engines   
5   Machine Guns, Internal Combustion Engines, Aeroplanes
6   Radar, Pressurized Aeroplane Cabins
7   Early Computers, Satellites, Guided Missiles, Fission Power
8   World Wide Computer Networks, Stealth Aircraft
9   Laser Weapons, Anti Gravity, Jump Drive 1
10   Thrusters, Grav Plates, Fusion Power
11   Jump Drive 2
12   Jump Drive 3
13   Inertial Dampers, Jump Drive 4
14   Jump Drive 5
15   Jump Drive 6