A weird resource that I thought I’d share: I dug through all the examples I could of speculative trade in space-themed tabletop RPGs, briefly summarized each one in a paragraph, and then stitched the whole damn thing together. The goal was to get a feel for what’s been tried before and what the current “state of the art” might be. What I learned was there’s actually far fewer examples of speculative trade than I’d originally thought!
In any case, here they are. I’ve saved my editorializing for the very end. Oh, and I snuck in one example of an Age of Sail game (and, uh, a few video games) because they seemed like good or important examples. Be sure to let me know if I’ve missed anything and I’ll add it to the big list.
Basic Traveller (Book 2, Second Edition, pp. 46-48)
There are 36 available trade goods. GMs roll to determine which 1 good is currently available on a given planet. Each trade good has a base price. This is then modified at the point of purchase or sale by a percentage value pulled from a 2d6 table, with a 7 result indicating that the base price is unadjusted. This price roll is adjusted by relevant character skills and any NPCs hired to help. The type of good and planet the trade is being made on is also a factor: there are 6 “world types” and each one adjusts the price roll for particular trade goods up or down.
Classic Traveller (Book 7, Merchant Prince, pp.34-42)
Trade goods are classified based on their source planet. Each source planet has some combination of 15 different trade classifications, along with a tech level and a starport type. These are associated with modifiers that are added and subtracted from a base purchase price of 4,000 credits. When sold, a table is consulted comparing the trade classifications and tech level of the source planet with those of the planet the sale is taking place on. This table produces a modifier to a base sale cost of 5,000 credits, which is adjusted one last time by a percentage value determined by a 2d6 roll. This final roll can be modified by character skills and/or hired NPC brokers.
Stars Without Number (Revised/Deluxe Edition, p.235)
There are 3 categories of trade goods available: cheap, ordinary and expensive. Each has a base purchase price determined by a 2d6 roll, and a base sale price determined by a 2d6+1 roll. Characters can make an opposed Trade skill check to adjust the final purchase or sale price. In either case, a 1d6 roll is made after the trade is completed, and a 1 result indicates a catastrophe has occurred: the players lose the money involved in the deal unless they “take whatever adventurous steps are necessary” to resolve the situation.
Suns of Gold (SWN supplement, pp.13-19)
Every planet has 10 trade goods available, pulled from a list of 34, with the option for GMs to create additional ones. 2 of these goods are randomly determined to be available for purchase at any given time. Their base purchase or sale price is adjusted by a percentage value pulled from a 3d6 table. This roll is adjusted by the planet’s trade modifiers (a small assortment picked from a list of 20), along with the character’s skills and a number called Friction. Friction is a representation of a planet’s bureaucracy, and always negatively affects a trade. After any transaction, 1d10 is rolled, with low results indicating that some sort of “trouble” occurs that can raise a planet’s Friction, waste the player’s time, or worse.
Star Wars: The Roleplaying Game (Galaxy Guide 6: Tramp Freighters, pp. 14-18, 94)
There are 6 technology levels for planets, and 8 general categories of trade goods. Each technology level has a sale price, purchase price and supply/demand rating for each category of trade good. Characters must make a skill check to find an NPC to trade with, based on the desired good’s supply/demand rating. They also make an opposed skill check to determine the final sale or purchase price, with the maximum variance being +/-10%.
Out on the Rim (unreleased)
There are 13 categories of trade good. Each category has the same base price. Characters trade by reaching out to an NPC contact and making a skill check. The contact will buy or sell any trade goods that are narratively appropriate for their base price, but will trade several randomly determined categories at a slight premium or discount depending on the results of the skill check. Planets can also have a permanent premium or discount on specific trade good categories to represent unique scarcities or surpluses.
Impulse Drive (p. 41)
Currency is abstracted in Impulse Drive. The players’ ship has a unique “good things that can happen after you’ve been paid” list. Obtaining goods for trade is a simple modified 2d6 roll that results in obtaining one of 3 types of goods. Selling those goods is a separate 2d6 roll, modified by how valuable the previously obtained cargo was. A good result can allow the players to choose an option from their “good things” list; a poor one results in their simply swapping for another cargo, or getting nothing at all.
Ashen Stars (p. 173)
Trade and cargo sales are abstracted out as “side deals” to regular missions. Characters can make a skill check to haggle over price, but generally, a side deal pays 20% of whatever the players are being paid for the job that is the focus of the session. Possessing a ship with a large cargo hold gives a bonus to this skill check. Side deals are intended to cause issues with a session’s primary mission, or otherwise put the characters in harm’s way.
Ultraviolet Grasslands, v1.0 (Free Introduction, pp. 54-57)
There are 30 distinct and flavorful trade goods, each with a base purchase price. Characters can make a skill check to spend time determining the sale price of a given trade good in a nearby destination. Better results indicate the sale price will be a multiplier of the base price (x1 to x3). When eventually making a sale, characters can make another skill check to haggle over the final price, with high results multiplying the sale price further (x1 to x2), and low results causing the deal to fall through. There are additional rules for delegating a profitable route to an NPC employee.
Ultraviolet Grasslands (pp. 176-178)
There are 30 distinct and flavorful trade goods, each with a base purchase price and suggested original source location. Characters can make a skill check to spend time and money determining the price of a given trade good in a nearby destination. Better results indicate the price will be a multiplier of the base price (x1 to, rarely, x3-6). When making a purchase or a sale, characters make another skill check to haggle over the final price. High results adjust the price in the character’s favor, while low results can cause the deal to evaporate. Profitable routes can be delegated to NPC employees, and their return is decided by rolling 1d20 on one of three tables, each representing a different level of risk and reward.
Wing Commander: Privateer (video game)
There are 40 available trade goods. There are also 5 general categories of port/location, along with 4 unique ports. Each port category has a value set for every trade good, with a small amount of random fluctuation between specific ports. Port categories will purchase most trade goods at the rate they value them, as well as sell an appropriate subset at their valued rate. Port categories that produce a given good tend to value them lower than other port categories.
Sunless Skies (video game)
The largest port in each area of the game will buy every basic trade good (14 in all) at its base price, and sell none of them. Outlying ports each sell a unique selection of goods at base price, but purchase none. In order to turn a profit, a player must take advantage of Prospects, which are contracts from the largest port obliging a client at an outlying port to purchase an amount of a trade good at a premium rate, and Bargains, which are opportunities at outlying ports to purchase an amount of a trade good at a discount. Smuggling involves taking on more lucrative Prospects involving 3 unique contraband goods that can cause various issues while carried.
Horizon’s Gate (video game)
Each port produces a trade good, pulled from a list of 14. All ports will always buy trade goods, paying the base price plus a premium based on how far they are from a port that produces a particular good. Trade good supply is limited, with ports producing additional units of a good according to an in-game calendar. This rate can be increased by investing currency into a port’s development. Once per in-game month, one port in the world will pay double for the first shipment of a random trade good. This information is initially hidden, but can be stumbled upon or sought out by a player.
I said I was going to editorialize a bit at the end, so here’s a shotgun blast of my thoughts on this exercise.
The Classic Traveller rules have way too much going on. While historically I’ve appreciated that they give you the freedom to describe speculative goods as whatever you think would be available on a given planet, there are so many variables involved in computing base prices that these would absolutely bog down in play.
Similarly, the Suns of Gold rules, historically one of my favorite sets, might have a little too much going on. Creating a slate of goods for a world AND setting a starting Friction number AND choosing a “trouble” number to roll under AND developing troubles that could conceivably hit a player party is an awful lot of work and potentially a little too… artificial feeling? That said…
Stars Without Number’s “1d6 for the deal to go south” is great. I’ve become more fond of tying speculative trade more directly into the generation of adventure seeds, and this is quite literally that on a silver platter.
I had forgotten that Friction in the Suns of Gold rules was meant to also encompass operating costs like docking fees and refueling. I like that a lot! Having both a trouble roll and Friction still strikes me as a little clunky, but there’s something to that level of abstraction. It’s almost like people have been talking up Suns of Gold for years for a reason! :)
Sunless Skies is probably my favorite system I’ve seen/played so far. An older post on their blog goes into the detail behind the design, and I appreciate that they were going for something that made you feel like a canny trader, rather than something that explicitly simulated an economy. A side note that I didn’t drop into my write-up is that you can usually fulfull Prospects through multiple means. A generic space example would be receiving a Propsect to deliver 5 Scrap to an outling port: while the obvious way to do that would be to head to the port that produces Scrap and buy 5, you might also have bought some cheap Scrap from a Bargain earlier that you can use for greater profit, or you might be able to go blow something up or salvage a derelict to earn the required Scrap the hard (and probably more fun) way. Options!
1/20/2021: Added Ultraviolet Grasslands and UVG: Free Introduction. The differences between the two are subtle, but I think significant enough to warrant separate entries.