This is actually the original of what became my HackTrade article. I wrote it because a player had too much money, and wanted to invest some. I came up with a modified version of what I call "The core crunch" on the spot (it was more generous, and made a positive return likely), and then built the article around it. When I got into Hackmaster a bit later, I polished the idea into HackTrade.
Capital and Caravans
Basic Investing for Castles and Crusades
There comes a point in many games when the characters simply have too much money. They may have purchased everything the CK will let them purchase, may be on the move and unwilling to buy real property (houses, bars and the inevitable stronghold), or may simply be wanting to make more money when they’re in that limbo between being having to scrape every last copper and being able to destabilize the local economy without half trying. Some mercantile-minded players may turn their minds towards investing some of their rewards in commercial ventures, hoping for a return in wealth and influence. Unless you truly wish to be playing Capital and Caravans, however, most CKs will seek to abstract this process a little, letting the game flow without preventing the character from spending his wealth as he sees fit.
Investments are of two different types: caravans and in-place businesses. Many of the same principles apply to each, but some modifiers will have different effects depending on whether or not the business venture travels.
The Core Crunch
Before I spend a long time discussing the options in dealing with investment, let’s look at the core mechanic of simple investing: 2d8*10%. That’s the average return on investment for the gentleman adventurer. For those who don’t do the probabilities in your head, this means that, on average, an investor will see 90% of his money back; if he gave the merchant ten gold pieces, he gets back nine, for a net loss of one gold. This is intentionally not fair. A great many business ventures lose money, and if all the character has done is toss money at an investment, he will likely lose money. This number is, also, simply return on investment. It does not include taxes that might need to be paid or fees that accrue, which tends to drive returns even lower.
The average time for maturity on any investment is one month. This allows a trade caravan to make it to another city, sell its wares, buy more, and sell those upon return. For an in-place business, this covers a period of purchases and sales. Some investments may take longer to mature, or players may look to make quick money through short-term loans of a few days or weeks. All of these can be handled through similar mechanics, but shorter-term investments tend to carry a LOT more risks, while long-term ventures tend to be more stable. For short term investments, I suggest a return of (1d20-1d4)*10%; you’re far more likely to lose your shirt, but your returns will rarely be much higher. For longer-term investments, I suggest (2d6+1d4)*10%; the floor is higher, the ceiling about the same, and the average about the same.
What makes merchants (and adventuring venture capitalists) profitable is research, hard work, and a bit of luck.