Last modified March 24, 1997

Scott Orr's Internal Trade Rules

Okay, here are the rules, which were also posted about a year ago. A couple of notes:

1. The rules may create balance problems, since they create a "snowball" effect for a big empire. OTOH, they also give smaller empires an even bigger incentive to cooperate--and the rules do have a diminishing-returns feature, which keeps things from getting out of hand.

2. The rules are rather heavily weighted towards small populations (on the grounds that new populations bring new, unique resources), in order to encourage colonization. I don't know that as much encouragement will be needed under the SM #2 rules.

15.XX Trade (optional rule)

Planetary economies do not exist in isolation. Where there is interstellar civilization, there will also be interstellar trade: the exchange of unique resources, and the creation of ever-larger markets, with the accompanying economies of scale, makes the whole of an empire far more than the sum of its parts. The same is also true, to a lesser extent, of trade _between_ empires. This rule, if used, replaces the trade bonus described in 17.02.05 (Trade Intercourse).


Each empire (player or NPR) receives an _internal_ Trade Bonus for each population (including the homeworld). To calculate the bonus, assign each population a Trade Number; a population's Trade Number is based on its size:

Size Trade Number
Outpost 1
Colony 2
Settlement 3
Small 4
Medium 5
Large 6
Very Large 7

The Trade Number of any population located on a habitable world (T or ST -- the race of the population is irrelevant for the purposes of this rule) is doubled because of the value of unique biological resources (hence, in practice, all Very Large populations have a Trade Number of 14). Note that this gives smaller populations a good deal of weight in the trading system, which accounts for the unusual goods and commodities that each new population brings to the empire. If for any reason the populations of two or more different empires occupy the same system body, each contributes separately to the Trade Bonus of its parent empire.

The total Trade Bonus for the empire, expressed as a percentage of GPV, is equal to the sum of the Trade Numbers of all populations, divided by 10. For example, an empire with one Very Large (habitable), two Small (habitable), 2 Settlement (habitable), 1 habitable Colony, 4 non-habitable Colony, 6 habitable Outpost, and 12 non-habitable Outpost populations would receive a bonus of (1*2*7 + 2*2*4 + 2*2*3 + 1*2*2 + 4*2 + 6*2*1 + 12*1) / 10 = 7.8, or 7.8% of GPV. The Trade Bonus is added to the GPV of each population in the empire (for example, a population with a GPV of a 100MC in an empire with a 10% Trade Bonus would receive a bonus 10MC), and is received as normal income at the system of the population that receives the bonus (hence, the player would receive 110MC in the system containing the population in the previous example).


Because the trading infrastructure in any given system is limited by the size of its largest population, and because the bodies in any one system tend to have similar resources (particularly in the case of asteroids), the Trade Bonus contributed by any one system is limited to twice the Trade Bonus of its largest population (for example, a system with a Very Large population, Trade Number 14, could contribute at most a Trade Bonus of 2.8). In systems with more than one population of size Small or larger, the maximum Trade Bonus for the system is equal to twice the sum of the Trade Bonuses of all such populations.


If the empire has a Trade Intercourse, Trade & Military Alliance, or Partnership relationship with another empire (or any other relationship for which a trade bonus would be received), each empire receives an _external_ Trade Bonus equal to half the Trade Bonus of the other empire. For example, if two empires, with internal Trade Bonuses of 10 and 16 respectively, were to enter into a Trade Intercourse relationship, the first empire would receive a total Trade Bonus of 10 + 0.5*16 = 18, and the second empire would receive a total Trade Bonus of 16 + 0.5*10 = 21. If the other empire has a TL two or more levels less than that of empire receiving the external Trade Bonus, the Bonus is halved again (making it one quarter of the other empire's internal Trade Bonus). Hence, if the two empires above were HT4 and HT2, respectively, the first empire would receive a Bonus of 10 + 0.5*0.5*16 = 14, while the Bonus received by the second empire would remain at 16 + 0.5*10 = 21. In practice, this means that the net benefit of trade will be approximately equal (in terms of absolute number of MC's received each turn) for empires of similar Tech Levels.

For purposes of trade, a conquered population is treated as a foreign empire; i.e., the conquering empire receives no Trade Bonus for the conquered population until a relationship of Trade Intercourse, Trade & Military Alliance, or Partnership is achieved, and does not receive the full bonus until it Amalgamates the conquered population.


Because similar sources of even the most unique resources may exist, and because economies of scale have their limits, the benefit of adding new populations to the trading system is reduced after a certain point. To reflect this, after the total Trade Bonus (from all internal and external sources combined) reaches 25, the Bonus contributed by any new populations is halved; once the Bonus reaches 50, the added Bonus is quartered; once it reaches 75, the added Bonus is one eighth of normal, etc. (keep all fractions). Hence, an empire with a "basic" Trade Bonus of 45 (for example, an internal Bonus of 30 and and external Bonus of 15), would receive an actual Trade Bonus of 25 + 20 / 2 = 35; an empire with a "basic" Trade Bonus of 62 would receive an actual Bonus of 25 + 25 / 2 + 12 / 4 = 40.5.


The Trade Bonus is always transported via the IFN, whether or not income from other sources is transferred among systems. The amount of income actually transported is equal to 10 times the income received from the trading bonus, and any of this income lost to raiding is deducted from next turn's income for the trading empire (the loss may be distributed as the controlling player sees fit among any populations within 2 hops of the system where the loss occurs, so long as no population's income is reduced below 50% of its GPV). [Newer raiding rules ought to flesh this out -- for the moment, as a rule of thumb the trade income passing through any given system can be estimated as being equal to 10 times the Trade Bonus for the empire multiplied by the total GPV of all populations within 2 "hops" that contribute to that empire's Trade Bonus, with GPV halved for conquered populations or those belonging to other empires.]

If the empire is divided into two parts (see 20.02.03 and 20.02.04), the Trade Bonus is calculated separately for each half of the empire (the presence or absense of an imperial capital or ICC is irrelevant for this purpose); any external Trade Bonuses are received or contributed only by the part(s) of the empire actually in contact with the other empires contributing and receiving the external Bonuses.

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