Saturday, 15 October 2011

Trade Makes the Galaxy Go Round

Cover of GURPs: Traveller - Far TraderI’m still crunching away at the trade figures for the RimWorlds. At present, I have covered most of Lymethius and Gamelea Subsectors and already some interesting patterns are beginning to emerge.

GURPs: Traveller - Far Trader works by creating a World Trade Number for each main world – derived from that world’s Tech Level and population, and modified by the Starport type. An individual planet’s World Trade Number ranges from 0 to 6.5.

The World Trade Numbers of two worlds are added together, modified by Trade Classification type, if applicable, and by the distance in parsecs between the two worlds. The resulting number is called the Bilateral Trade Number and represents the amount of trade between the two worlds in question. What we are looking for is the existence of Major, Minor and Feeder Trade Routes associated with Bilateral Trade Numbers of 10+, 9+ and 8+.

Where GURPs: Traveller - Far Trader is quite clever, is that the distance modifier uses a logarithmic scale. This means that while the serious negative modifier of –2 kicks in at 10 parsecs separation, it is still possible to have a Major Trade Route between two planets up to 19 Parsecs apart, assuming each had a World Trade Number of at least 6 and both were members of the same polity. If there are sufficient High Tech/High Population worlds, they will naturally daisy chain and create lucrative Mains.

Where this information becomes useful from a gaming point of view is when you want an idea of how much traffic, and of what tonnage, is likely to be in a system, and how much freight and passengers are likely to be hanging around, waiting for a ride.

Be prepared however, if you want to use GURPs: Traveller - Far Trader as an economic mapping tool, for a lot of initial work. While parts of the job can be auto-calced by a bit of cunning Exel-fu, there is a lot of tedious manual matching of pairs of WTNs with distance modifiers to arrive at BTNs. Though, if you stick to the formula rules, you can quickly correct any initial calculation errors – such as happened to me this evening when I realised that Acorlis V’s WTN was wrong; once this was fixed, the BTNs I had laboriously calculated all corrected themselves – which was a relief – and the trade routes I had noted leading to Acorlis V all disappeared as the BTNs had dropped below the Feeder Route threshold – which makes sense as Acorlis V is best described as a dusty pest hole the inhabitants are too poor to leave.


  1. I like your focus on Traveller. Very inspirational.

    Feel free to check my blog for my converted Imperial Marines in battledress/combat armor.

    Strike from Space!

  2. You have done an amazing job on those marines, very impressive!