Monthly Archives: February 2015

Gravitics Handwavium

The handwavium for how gravitics works IMTU.


Basic Idea

Some kind of power source that creates a field which reacts with gravity. The polarity of the field can be adjusted such that the gravitational force is applied differently.

Earliest/cheapest grav tech can simply reverse the field so gravity provides lift.

First gravs were: large external power source, sea level, external power applied to field generator attached to a chassis, result the chassis rising above the ground and hovering – hover sled.

Over time improved: power source small enough to be carried on the chassis, solid hover ability, separate source of thrust – hover tank.

Over time improved: field generates multiple of G force so can lift rapidly also field can be angled to give thrust and lift – flying tank.

Over time improved: full air/raft functionality.


Secondhand Market

Re-conditioned grav components from scrapyards are jury-rigged into black box components on systems like Glisten for sale on backwater planets. The advanced controllers are generally removed so components only provide lift but they can be bolted onto platforms and switched on and off which is the minimum needed. Grav parts like this are used on hundreds of lotech worlds with the thrust supplied in hundreds of different ways including animals, steam engines, wind etc.

Basic reconditioned grav parts and spare parts for other tech is a very common Free Trader cargo.

A lot of backwater systems have a hybrid kind of gravpunk technology where the cheapest kind of grav tech is combined with local tech capability so John Carter on Mars type planets can exist in the remote parts of the 3rd Imperium where the dreadnought fleets never go.

Useful Links


Spacey Science Stuff


Traveller Specific


published world maps & info

jump shadow



submarine tour (400 or 600 dton in Traveller terms


liberty ship (2000 dtons)





Vilani: GURPS Interstellar Wars

Hydroponics / Life Support:  T4 Fire, Fusion and Steel

Megatraveller: Imperial Encyclopaedia



worth thinking about space elevators re temp space ports


Campaigny Stuff

LBB only

Space Energy Weapons (WIP)

1) Energy and range are linked by a square law so if the range is doubled the energy in the beam is reduced to a fourth. So if a beam has a strength of 4  at range 1 then it only has a strength of 1 at range 2

2) So range bands should be a power of 2, say 1, 2, 4, 8 so short = 1, medium = 2, long = 4, very long = 8

3) If minimum penetration is given an arbitrary value of 1 (representing some unspecified amount of energy) then

– a penetration value of 1 at short range requires a minimum initial strength of 1

– a penetration value of 1 at medium range requires a minimum initial strength of 4 (range doubles so strength/4)

– a penetration value of 1 at long range requires a minimum initial strength of 16 (giving a strength of 16 at short range, a strength of 4 at medium range and a strength of 1 at long range)

– a penetration value of 1 at very long range requires a minimum initial strength of 64 (giving a strength of 64 at short range, a strength of 16 at medium range, a strength of 4 at long range and a strength of 1 at very long range)


For scenery say laser weapons are rated in pounders after Dr Yukio Pounder so

– a strength 1 laser is a one pounder

– a strength 2 laser is a two pounder

– a strength 64 laser is a sixty-four pounder



One way to keep it simple is to say a dedicated war ship can have one laser point for each 100 dtons displacement (in reality this would vary by TL) so a 100 dton ship can have 1, a 3200 dton ship can have 32 etc arranged as desired in any combination, for example

100dt ship: 1×1 pounder

200dt ship: 2×1 pounder or 1×2 pounder

1600dt ship: 1×16 pounder or 4×4 pounder or 1×8 pounder and 2×4 pounder etc

12,800 dton ship with 128 total points of energy weapon potential might have

1×64 pounder for very long range

2×16 pounder for long range

4×4 pounder for medium range

4xquad1 pounder for short range point defense (quad = four one pounders in a turret)

total firepower would be

128 at short range

28 at medium range

6 at long range

1 at very long range

Trade Network


My Spinward Marches Trade Map


(courtesy of the awesome )

  • dark green routes are the hinterland routes
  • purple are the long distance routes between alpha systems – these also overlay some of the hinterland routes
  • light green routes are subsidized by the Imperium for policy reasons (e.g. building up border systems)
  • yellow circles are alpha systems (and sub-sector capitals if different)


Trade Assumptions

1) Systems represent whole solar systems so from TL9+ onwards worlds can easily be self-sufficient in raw materials.

2) Interstellar shipping costs per ton per parsec are high so

  • it’s only going to be economic to ship low value goods a short distance, say one or two parsecs, and only to systems which might have demand in excess of what the system can produce itself
  • medium value goods are restricted in a similar way, say up to six parsecs
  • high value goods: tech, luxury items, rare materials, unique planetary items etc can be profitably transported long distances but only in large amounts to systems which have a high demand for high value goods i.e. rich, high population planets



Trade in Traveller will mostly revolve around the alpha planets.

(Defined IMTU as class A star port, pop 8+, TL 12+.)

1) The alpha systems have high value tech to trade for what they want.

2) The alpha systems might have a demand for common raw materials because they have already used up the easiest sources in their system so deep mined local copper might be more expensive than copper that is open mined on a nearby system and then shipped – as long as it is nearby.

3) Assuming that an alpha planet can always grow enough food to feed their billions even if it’s in vats or on orbital stations or whatever they might still consider “natural” food items as a luxury or preference especially things like meat and fruit so I can see alpha systems having a demand for those from nearby systems – again stressing nearby.

4) The alpha planets will provide the main market for high value goods simply because their population size and TL implies they will have a large market and lots of prosperous or wealthy individuals.

So the alpha planets are the main markets and provide the hubs of trade.



If you accept the conclusion then the nature of trade in the Imperium will resolve into three main categories:

1) Hinterland Trade

Each Alpha system will have a cluster of systems around them which are tied to that Alpha’s economy. The hinterland systems will generally provide something useful for tech.

  • very short distance, 1-2 parsecs, for low value goods
  • short distance, up to 6 parsecs for medium value goods

The clusters made up of an alpha and its hinterland would once have been the core of the many pocket empires swallowed up by the Imperium as it expanded.

2) Silk Road Trade

Long distance trade between the alphas. Ships plying these routes don’t need to trade with the systems in between so these routes generally take the form of truck stops with an orbital refueling station by an outer gas giant or ice planet. The hub to hub ships just jump in, dock, refuel and do maintenance checks at the space station then jump out again. They only stop to unload when they reach the destination. Silk road truck stops will generally have a small 3I naval base for protection – like a Roman fort.

3) BackwaterTrade

Most everywhere else will have relatively low volumes of trade providing a living for Book 2 type subsidized merchants and Free Traders.



The alpha planets will often have orders of magnitude more people, GDP, tax etc than the rest of their sub-sector so not only will they both physically produce the fleets and provide the revenue to support them – so in terms of fleets – the bedrock of the Imperium – the alpha planets are what matters.

More specifically what matters in order
1) alpha planets
2) routes between the alpha planets
3) border fortress systems
4) alpha clusters
5) everywhere else

This leads to my 3I being split into three layers

  • there is a big ship universe of dreadnoughts and megacorporations comprising all the alpha systems and the silk road systems linking them
  • there is a medium ship universe in the hinterland systems of each alpha cluster
  • there is a small ship universe everywhere else where the 3I is rarely seen

(where small <= 1200-1600, medium <= 5k dtons, big > 5k dtons)


Which systems are which?

You could do it the GURPS way of giving systems a trade value based on their world stats but I think the potential self-sufficiency of systems and the consequent randomness of whether or not a system has something worth selling to an alpha makes a random element to trade value both plausible and potentially more interesting so IMTU I’m going to treat the canon star port class as the indicator of trade value i.e. if they built it there was a good reason so:

1) Alpha Systems: the alpha systems are defined as class A, pop 8+, TL 12+ (and sub-sector capitals)

2) Hinterland Systems: non-alpha systems with A or B star ports within 6 parsecs of an alpha system are assumed to have something to sell to the alpha in exchange for tech and are part of that alpha’s hinterland cluster

3) Exotic Systems: A or B systems outside of an alpha cluster (more than 6 parsecs) will generally have an exotic explanation. It could be something shady, historical or unusual like the system is being actively built up by the Imperium for some reason with regular colonist ships from the core

4) Backwater Systems: C, D and E systems are assumed to not have much anyone else needs and so have a low volume of trade serviced by Book 2 type ships

5) Silk Road Truck Stops: systems that make convenient refueling stops on the silk road.

6) Hinterland Truck Stops: systems that make convenient refueling stops on hinterland routes.


Example: Glisten sub-sector

1) Glisten is an alpha system.

2) Mertactor, Mille Falcs, Egypt, Overnale, New Rome, Aki, Weiss, Dobham are all hinterland systems and part of Glisten’s cluster

3) Romar, Bendor, Squanine, Ffudn are both hinterland systems and silk road truck stops

4) Mithras, as a prison planet is part of Glisten’s hinterland also

5) Grote is an exotic exception system – it could be a system being actively built up by the Imperium as a border fortress and link to District 268 or something odd / shady.

6) Aster, Melior, Craw, Horosho, Wurzburg, Lydia, Centry, Bicornn, Crout, Tirem, Caledonia are backwaters

7) Callia, Sorel, Tsarina, Windsor, Trane, Inthe are backwaters and hinterland truck stops

8) Marastan is a backwater and a silk road truck stop

  • systems like this are part BSU and part SSU and will generally have a commercial orbital station which services the passing merchant ships and small ships linking to the planet itself. Players jumping into the system might see lots of big silk road freighters and lots of patrolling fighters between the naval station and the jump points but very little traffic near the main planet.


Ship Encounters

Alpha Systems
  • very busy, lots of colonized planets and moons, lots of habitats, masses of internal traffic plus lots of large, medium and small interstellar traffic. Lots of planetary defenses – especially around fuel sources. Naval ships up to dreadnoughts. Silk road patrol ships.
Hinterland Systems
  • less busy, medium and small commercial ships, medium naval patrol ships.
Backwater Systems
  • quiet, small commercial ships, belters, scouts, small naval patrol ships.


Imperial Nobility

The Imperium is huge and travel is slow so the Capital may be a year or more away from the frontier.


Historically this sort of problem is solved by decentralization and the problem that arises from that – risk of rebellion – is solved with some kind of feudal structure – hence the importance of the nobility in Traveller.


There are a lot of different historical models for this so the question is which suits the Traveller OTU best.

Apparently the Traveller nobility were based on the Russian Imperial model of Boyars and that does seem to me to be a good model.

So I’ll use that as the basis for the nobility IMTU

The key distinction is that being a member of the Boyar class doesn’t automatically imply actual Imperial authority. Imperial authority comes from Imperial titles. Being a member of the Boyar class is pre-requisite for getting a title but the two are separate.


Becoming  Boyar

When someone reaches certain ranks in the Imperial service (particularly the Navy) they get either a lifetime or hereditary knighthood and become part of the Boyar class e.g. a Navy Captain gets an honorary knighthood and lifetime membership of the Boyars, an Admiral gets a hereditary knighthood.

A lifetime knight gets the title and some standard perks like the right to bear arms. A banner knight gets those and also a knight’s fee – ttile to some land and a hereditary source of income.

Knight’s Fee

Let’s say the Imperium taxes 25% of star port revenue traditionally divided

– 5% to Capital

– 5% to Sector

– 5% to Sub-Sector

– 10% as knight’s fees

Say traditionally a knight’s fee was 0.001% of a star port’s revenue so the 10% above would be 10,000 knight’s fees however this was A class star ports on the core worlds so the percentage may vary greatly. A knight’s fee from a C star port on a backwater planet might be 1% and ten knights. The fee from an even more backwater D star port might the full 10% and a single knight.

Once a Boyar then additional promotion to an Imperial title gains extra fees.

If a later member of a Boyar family also reaches such a rank they get additional knight’s fees.


The Imperium is governed through titles. For example the commander of a sub-sector’s scout service might have the title of Baron-Commander. The commander of a sector scout service has the title Count-Commander. The commander of a particular interdiction or imperial prison planet might be a knight-commander.

So knight and banner knight simply denote Boyar status. Knight-commander, Baron, Count, Duke etc denote Imperial titles and the titles confer imperial authority over their assigned facet of imperial governance.

Sample Career

A commoner joins the navy and rises to Captain and is knighted, switches to “Noble” career and spends a term as the Knight-Commander of a prison ship followed by a term as the Baron-Commander of a designated colony project, then a term as the Count-Commander of the sector scout service then a term as sub-sector Duke and then finally a term as sector Duke.

Each promotion would get a fee so five fees in this case.

If their great-grandson becomes an admiral later they would add another fee to the family collection.


Types of Noble

The distinction between Boyar and title means there are various types of noble.

1) Standard Banner Knight

The family gained a fee or two some time in the past but haven’t added more to it since. They have an estate and some funds but they are not wealthy. Most join the Imperial service in some form for some amount of time.

2) Wealthy Banner Knight

Often these are families that got fees on under developed planets that have since developed. A Boyar family who owned a lot of the land around a D star port on a low population world which eventually grew into a B star port on a developed world might own 10% of everything on the planet. The family would still only be Boyars and have no imperial authority but could be fabulously wealthy with a great deal of unofficial authority based on their wealth and local status. A family like that could actually run things behind the scenes with any government type.

3) Imperial Title

A Knight (from either of the two backgrounds above) who has an imperial title will have authority and power commensurate with their position: a Knight-Commander of an interdiction might have a squadron of ships, a Knight-Ambassador on a minor system might have an Imperial Ambassador’s yacht, an escort ship and a company of marines, a sub-sector Duke will generally have a massive war fleet. Once the person leaves the position the assets that came with the title are lost.

4) Hereditary Imperial Title

Although the system is designed not to be hereditary at various times and places hereditary titles were granted generally due to a temporary weakness of central Imperial authority. Once given they are hard to get back although the imperial center tries whenever it can.

5) Hereditary non-Imperial Title

In some situations the rulers of a system incorporated into the Imperium may have been given an honorary title. The power and authority of the family depends on their local power base and has no imperial backing. The title is a status and courtesy thing (but may include perks like right to bear arms and huscarls).


Noble Perks

The standard Boyar perks are the right to bear arms and a fee (land and income) if hereditary. Further fees can include the right to armed household retainers known as “Huscarls”.

Further fees can be taken from a random table from issue #2 found here

Noble Careers

Using this char gen  shoul dhave two noble careers.

1) An independent noble with lots of varied skill tables to choose from from farming to space exploration to business.

2) An extension of the standard char gen such that a character that reaches a Boyar rank can switch to an Imperial administration career path. This would be a bit like the Roman Cursus Honorarum.

Adventure Ideas

As they come

1) Tiger Hunt

Players on a backwater planet after doing some favor for a local Prince (maybe just bringing some trade goods for example) get invited to take part in a Tiger hunt. The transport is the local equivalent of elephants and the prey is the local equivalent of tiger. The elephants have armored drapes protecting them but the Prince’s elephant’s armor is sabotaged (either allows tiger inside under elephant’s legs leading to panic or through falling off taking the Prince’s howdah to the ground). Players need to save the Prince and then find the culprit.

2) Artist

Remote, corrosive atmosphere, fluid ocean, (could be prison planet: Glisten/Mithras?) – reclusive artist in residence in some abandoned rock tower / research / lighthouse type building collects fluid from rock pools at low tide and uses it in a form of hitech glass blowing to create famous and valuable art. An art collector too far down the waiting list is in a hurry and wants one stolen or agent wants news – artist hostage of dudes planning prison break? Sealed tower has submersible entrance maybe, environmental hazards, weird critters, maybe a prison break involved – mini trek through dangerous terrain followed by mini dungeon followed by main scene and escape.

3) Magnificent Seven

Think Galaxy Quest. System under attack from pirates / renegades / bandits. Player ship attacked and crash lands. Wrecked colonial cruiser on ground. Players can get cruiser partly working with parts from their ship – no jump, 1G, some weapons etc. Pacifist natives can make up bulk of crew but need players to direct. Bk 2 ship battles with Vargr corsairs or something.

4) Space Janitors

Contracted to travel through a number of systems performing maintenance on navigation satellites. Come across satellite warning of a gravity rip-tide out of position with physical damage – repairing it find organic material like blood, (Byakhee crashed into it – hurt – smashed it.) Byakhee dropped onto planet nearest original position to heal up. Blood analysis triggers open anomaly report with a significant bounty.



General Ideas

from around

Scout/Small Ships

1) movable partition walls -> 4 x cramped state rooms, 2 x okay size, 1 x large

2) TV walls – programmable electronic wallpaper

3) ambient sounds

4) hitch hikers

5) scout couples – even families

6) scout service report database – updated at star port, search on a planet for fugitives, missing persons, anomalies etc




In Classic Traveller, Marines gain cutlass skill at basic training. This makes no sense but going with it for the sake of argument you could say that’s how they train vacc suit and zero-g combat. Marine ships and bases have zero-g training courts like squash courts with a viewing platform for spectators that involves dueling with cutlasses – bouts are a bit like jousting as contestants have to push off surfaces and strike as they pass.

This could then have turned into a major sport.



Jack of All Trades

Could treat JoT as a natural talent for a related set of skills. Characters pick one when they get it and it gives the equivalent of rank-0 in that set of skills.


  • JoT (repair)
  • JoT (melee)
  • JoT (ranged)
  • JoT (animals)
  • JoT(starship) (imtu scouts are get trained with this at basic but in reality are selected on the basis of having this as a latent natural talent)