Modeling economics (first of many parts)

In Sundog (the game), there were 30 types of cargo that could be transported by the pod (and thus by the ship), plus nothing and cryogens (the ‘green ice’ pods) — 32 types in all (because, binary). Each had an associated base price. Here’s the data from the original game, with the base price for each cargo type:

This is actually not a bad list to consider in Frasgird, at least to start with. The names are generic, suggestive and mostly understandable (“sunsuns” were portable fusion power units for home and industrial use).

The actual buying or selling price for a given cargo type on an actual exchange in a specific city on a specific planet in a specific system depended upon several additional factors. These included:

• A supply-and-demand factor that represented how much you had bought or sold of that type of cargo there recently (the factor reset to normal over a period of weeks). Each and every city had its own supply-and-demand table; the more often you bought a particular cargo in a particular city, the more expensive it got, and then it just wouldn’t show up in the marketplace for a while; likewise, selling the same cargo in the same city too often depressed the prices significantly. The bottom line was you couldn’t set up a profitable ‘milk run’ by shuttling between two cities on the same planet.
• The ‘wealth’ factor of the planet, a value in the range 0..15 that represented the general income level/standard of living of the planet.
• The ‘quality’ of the cargo, rated A..H (7..0), with ‘A’ (7) being highest.
• For certain ‘tech’ cargos (16..24 in the list above), the ‘tech’ factor of the planet.
• Whether you were buying at the (sole) spaceport on a given planet or whether you were buying at one of the other cities on that planet (25% bonus for selling, 20% discout for buying at a non-spaceport city).
• Whether you were selling a specific load of cargo in the same city, on the same planet, or in the same system where you bought it. (Yes, each cargo load ‘knew’ where it had been bought.)
• Whether you were selling the cargo to the colony-under-construction (they would pay a premium price for it — this was done mostly to reduce the grindingness of the game).

All this was implemented with a relatively small section of code, all using integer math (8-bit 6502 processor). But it was highly effective. I knew of players who used a second personal computer to keep track of the prices for goods in all visited cities.

However, Frasgird introduces a number of differences. For starters, the dominant sapient populations are alien, not human, and certain cargoes (such as food, clothing, etc.) would tend to be species-specific. Since different worlds will have different types and sizes of alien populations on them, it makes trading in general more complex but also more interesting. Likewise, cross-species trading would readily occur for many other cargo types, particularly for areas of specialization and expertise. And even than could vary. Alien art from a particular species might be highly prized by other species, but perhaps only on certain worlds or even just in certain cities.

More later.

About the Author

About the Author: Webster has been doing game design since 1980, but only has one actual published game to his credit -- Sundog: Frozen Legacy (Apple II, 1984; Atari ST, 1985). This is his second. More from this author.