For Your Review
This is something I posted way back in the olden days of the EN Boards when Eric ruled the roost. I haven't really updated in a while, but it may be useful to those that are looking for a framework...
d20 Economic System
by "Old One"
Economic System:
Introduction
The following is the economic system that I developed for the 3E. You can use it at several different levels and scale it to be as general or as specific as you would like it to be. Regardless of what level you choose, the mechanics are identical - you simply use the 'd20' mechanic.
You set a DC against which a campaign area, guild or trading caravan/fleet must roll to achieve success. The range is generally 8 (easy) to 12 (moderate), with the default being 10. Then you assign circumstance modifiers for whatever circumstances you wish to take into account, such as weather, bandit activity, technology level, magic assistance, etc.
Once you have determined the DC and applicable modifiers, roll a d20, add or subtract modifiers and compare the result to the table below:
Recommended Price Increase/Decrease
Example
Rastia is a campaign area located in temperate hills. The DC for growing food in the area is 11. Circumstance modifiers for the area are -2 (draft animals +2, rocky ground -2, monster activity -2). You roll an 8 on the d20, resulting in a modified roll of 6, which falls in the DC (-1) to (-5) range, a minor failure. This means that there will be minor food shortages in the area and food prices increase 70% (2d10 - 2+5 x 10%). If the price increase for shortages seem too harsh, just remember that the resident at in a typical fantasy world just can?t go down to the local Food Lion and get some hot dogs and mac & cheese!
Level 1
Very general: Uses very large categories, such as food, finished goods, etc. Usually determined once per game year to provide general background for the campaign.
Recommended categories:
Recommended DCs and Possible Circumstance Modifiers
Food - including crops, livestock, fish, etc.
Raw Materials (including lumber, stone, gold, silver, iron, etc.)
Note: Typically, the more heavily populated an area is, the more the natural resources and raw materials have been depleted, forcing civilizations to go farther and farther afield to secure raw materials to keep their economies going.
Trade Goods (including armor, weapons, spell components, wagons, ships, furniture, etc.)
Note: Typically, it is much easier to obtain trade goods easily in heavily populated areas and more difficult in sparsely populated ones, the exact reverse of raw materials.
Level 2
More specific. Works well if you want to add more detail to the campaign without being overly complex. Uses specific categories, such as cattle, horses, grain, gems, gold, silver, wine, etc. For each campaign area, select 2-5 (1d4+1) major industries that the area is known for and assign a modifier (usually in the -2 to +6 range). Your list of trade items and industries should be pertinent to your campaign - "candles" probably shouldn't be a category, but "magic components" might be.
Once per year or trading season, you make a roll for each industry/trade item to see what the supply looks like. You can use shortages and over-supply as good adventure hooks. City A has a severe shortage of silver, but City B has a major surplus. If the PCs can get a shipment from B to A, they will be rich (of course, bandits, rival groups and orc tribes may all try to get the shipment themselves)!
Possible Industries/Trade Items (by no means an exhaustive list):
Recommened DCs
This will be highly variable, depending on your game world. I recommend a range for 8 (very routine) to 12 or 14 (very difficult).Don't make the base DC too hard, or no trade would ever get done! You can make it tougher with appropriate circumstance modifiers.
Possible Circumstance Modifiers (in addition to those listed above):
Level 3
Very specific. Use if you want to have a detailed economic backdrop that is a major part of the campaign. Develop the industry/trade goods list for the campaign world, then assign a modifier for each area in each industry/trade good. So if you have 5 major countries and 12 industries/trade goods, you would assign a total of 60 modifiers. If you decide an area doesn't or can't produce a category (a desert city is unlikely to produce "fish", for instance), then they have to import it to get it and prices for those goods are likely to be 150% to 500% higher than normal.
If you are using a pseudo-medieval setting, you should also decide which guilds/trading houses/trading families/government institutions control or compete in the various trading areas (remember that the more competition in a given area, the lower the prices usually are).
For each category, determine success or failure. For each point the check exceeds the DC, the industry has the potential for a trading profit, determined by the number of people in the area that work in that industry (and your monetary system). To keep it easy, for basic materials (iron ore, food, lumber,etc), I usally use 1 gp x number of people in the industry x number the check exceeds the DC.
For example, Doria is a mining center, has 500 people working in the mining industry with a total modified DC of 11 for mining iron ore. You roll a 17 on the check. The potential profit is 1 gp x 500 people x 6 or 3,000 gp.
To realize the profit, Doria would need to make a "trading check" (new term - basically representing a trading caravan or trading fleet to move the goods to market). Again, you assign a DC and make the check.
The 1 gp per person in the industry works well for abstract items (ore, lumber, etc). For items listed in the PHB or DMG, work this a little differently. Use the industry check to see how much excess is produced (10% for each point above the DC), then mulitply by 1/10 of the item cost to determine potential profit.
For example, Doria also has many excellent dwarven armorsmiths who make superior chain mail. They typically produce 100 suits in a year. The DC for Armorsmithing in Doria is 10 and you roll a 14, so the smiths of Doria have produced 40% more armor this year, or 40 additional chain mail suits. Their potential profit 40 x 15 or 600 gp, subject to a successful trading check.
On the other hand, if an area fails checks for basic materials, like foodstuffs, you can reverse the procedure to see how much the rulers of the area need to fork over to keep their people from starving! I usually use 1 sp per person x the number you roll under the DC.
For example, Doria has a modified DC of 13 for food productin and rolls a 7, a major failure! The city has 8,000 inhabitants, so Doria will need to come up with 48,000 sp, or 4,800 gold, to stave off starvation (1 sp x 8,000 people x 6 below the DC).
Level 3 is really only for those that like to keep a very detailed campaign, but it is fairly easy to set all of this up on Excel spreadsheet and update it once a year. What I do is "net" the profit/costs for each area for the year (using Excel's sum operation). So I will have a good idea if there are going to be extra taxes in the area that year or if a big suplus is cause for a major celebration.
Level 4
Part 1
This level is designed to go down to the micro level and allow PCs to either interact/run a guild/business or to participate in trading caravans/voyages. I will tackle the Guild/Business aspect first.
Guild/Business:
The crafting rules on pp. 65/66 of the PHB are fine for crafting a single item, but what if you have a guild of 10 or 50 craftsmen? The system becomes a bit unwieldy. I recommend using the D20 trade mechanic to speed things up - using the following steps (we will use the Armorsmith's guild of Doria as an example):
(1) Determine the average skill check result for all guild members. Let's assume the Doria's Armorsmith's guild has 25 smiths - 1 grandmaster smith (+13), 3 master smiths (+10), 6 journeymen (+7) andd 15 apprentices (+4). Therefore,the guild's average skill check bonus is +5.8 - which rounds down to 5 (3E convention). Add this to the average d20 roll (10.5 rounded down to 10) for an average skill check number of 15.
(2) Next, multiply the average skill check number x the DC of the item being created. Let's say the the guild is creating chain mail armor (DC 15). 15 x 15 = 225.
(3) Then, divide the cost of the item being created, in silver pieces (chain mail armor, 150 gold = 1,500 silver) by the result from #2 above, resulting in 6.67 - rounded to 6. This is the number of weeks, on average, it takes 1 member of the guild to complete 1 suit of chain mail.
(4) If we are making an annual check, divide 52 weeks (for a standard year) by 6 - 8.67 - which rounds to 8, the average number of suits each guild member can finish in a year. So the Doria Armorsmithing Guild, in an average year, can create 200 (8 suits x 25 guild members) suits of chain mail armor.
(5) Lastly, we use our D20 Trade Mechanic to see how profitable the Guild is for the year. This is their routine craft, so set the base DC to 10. There are no unusual circumstance modifiers. You could, if desired, add in modifiers like:
Assume a base profit of 10% of the item cost, so the guild typically makes 150 silver, or 15 gold on each suit. So if they just made their check, their profit would be 3,000 gold for the year. Since they exceeded the check by 4, their profit was 40% higher, or 4,200 gold!
If the trade check roll had been a 2, then the profit for the year would have only been 2,100 gold.
This may seem like a lot of math and it does take some calculations to get it going, but then you can have a line entry similar to this:
Doria Armorsmithing Guild: (25 members, average skill check 15, base armorsmithing trade check 10, trade check bonus +5)
Let's look at another example, with the following guild:
Opal Shipwright's Guild: (80 members, average skill check 15, base shipwight trade check 12, trade check bonus +5)
Assume you want to know how many warships (p. 151, DMG) they can build in a year and what their profit is.
A warship costs 250,000 silver. Assume the DC for creating a warship is 14. 250,000/210 (ave. skill check 15 x DC 14). The result is 1,190.48 - round to 1,190. It would take 1 guild member 1,190 weeks to build 1 warship! Since we have 80 guild members, assume that all 80 are working on the ship. 1,190/80 is 14.88 - round to 14, so it takes the guild 14 weeks to build one warship.
That means that the guild could build, on average, 3 warships in a year's time (52/14, round down=3). How much profit do they make for the year?
The trade check DC is 12, but there has been a severe wood shortage (-4). The roll is a 10 - resulting in a final trade check of 11, just short of the DC of 12. This means that their profit is 15% below normal. So their total profit is 63,750 silver or 6,375 gold (25,000 silver x 3 warships x .85%).
Part 2
This last part is about how the PCs interact with the Economic System. This can be done several ways.
(1) PC's own a business - Sometimes, the PCs will want to own a business (usually in the crafting area). This is set up very similar to the way a guild is. Let's look at a quick example:
Larethin's Bows - Larethin is a bowyer and the PCs need a legitimate business front (or just want to make extra money). In addition to Larethin (+10 skill check modifier), the shop has one journeyman level bowyer (+7 skill check) and three apprentice level bowyers (+4 skill check).
(NOTE: As a general rule, for every three apprentices, you need a journeyman, for every three journeymen, you need a master and for every three masters, you need a grandmaster).
Since Larethin will be adventuring much of the time, we will need to do two stat blocks for the business, one with Larethin and one without. Our stat blocks look like this:
Larethin present: (Larethin's Bows - 5 members, ave. skill check 15, base bowyer trade check 12, base trade check bonus +5).
Larethin not present: (Larethin's Bows - 4 members, ave. skill check 14, base bowyer trade check 12, base trade check bonus +4).
Clearly, the shop will not be nearly as efficient when Larethin is out adventuring, but can still make some money. Let's assume that they make an equal amount of shortbows and longbows throughout the year (average cost of 525 silver). It takes the average employee 2 weeks (525/15*12, round down) to create a bow if Larethin is present and 3 weeks if he is not (525/14*12, round down).
(NOTE: When the PCs are running a business, it is usually better to do montly checks, as opposed to annual checks)
If Larethin is present, the shop can produce 10 bows (5/2 x 4 weeks, round down), equally split between longbows and shortbows. If he is not present, they can only produce 5 bows 4/3 x 4 weeks, round down), DMs choice on whether the 5th bow is long or short. You would then make the trading check normally, with the average profit per bow being 52.5 silver pieces. In addition, when Larethin is not present, he has to pay an extra 25% of profits to his senior person as an extra management fee!
(2) PCs are actively engaged in assisting the trading caravan/fleet/etc: - This is much more subjective, but in general, PCs with significant skill ranks (not total mods) in particular areas can have a positive impact on a trade mission.
For example, a PC with 5 or more ranks in wilderness lore could lend a +2 circumstance modifier to the trading check an overland trading caravan. A PC with 5 or more ranks in Knowledge: Navigation could do the same for a trading vessel. A PC with 5 or more ranks in Bluff or Diplomacy might be able to assist in trading negotiations, etc. At higher levels, spell casters might be able to enhance a trading check for an entire region (for instance, a high level druid casting a weather spell might add a +2 circumstance modifier to food production checks for an entire city or region).
Finally, you can use the trading check mechanic to pre-plan encounters on a journey instead of randomly determining them (whether or not they are involved in a trading mission). For instance, you determine that the overland journey from Doria to Restia is usually a DC 14. One of the PCs has 6 ranks in wilderness lore, giving a +2 circumstance modifier, but there has been unusually heavy bandit activity in the area, for a -4 circumstance modifier. You roll a 12, which is modified to a 10 (total of -2 circumstance modifier). I recommend that you have 1 encounter for every 2 points under the DC, so this roll would indicate 2 encounters during the journey - which you determine ahead of time instead of rolling for random encounters. Had the roll been 18, then you could just "fast forward" the party to Restia without repetitive rolling for each day of the journey.
Hopefully, you will find the Economic System useful at some level in your campaign
!
Best wishes,
~ Old One
This is something I posted way back in the olden days of the EN Boards when Eric ruled the roost. I haven't really updated in a while, but it may be useful to those that are looking for a framework...
d20 Economic System
by "Old One"
Economic System:
Introduction
The following is the economic system that I developed for the 3E. You can use it at several different levels and scale it to be as general or as specific as you would like it to be. Regardless of what level you choose, the mechanics are identical - you simply use the 'd20' mechanic.
You set a DC against which a campaign area, guild or trading caravan/fleet must roll to achieve success. The range is generally 8 (easy) to 12 (moderate), with the default being 10. Then you assign circumstance modifiers for whatever circumstances you wish to take into account, such as weather, bandit activity, technology level, magic assistance, etc.
Once you have determined the DC and applicable modifiers, roll a d20, add or subtract modifiers and compare the result to the table below:
* 1: Critical Failure(natural/man made disaster - fire, flood, war)
* DC (-6) +: Major Failure (severe shortages, prices skyrocket)
* DC (-1) to (-5): Minor Failure (minor shortages, prices increase)
* DC (0) to (+5): Regular Success
* DC (+6) +: Major Success (substantial surplus, prices decrease, significant exports)
* 20: Critical Success (market glut, prices plummet, major exports)
Recommended Price Increase/Decrease
* Major Failure - Prices increase 200% to 500% (1d4+1 x 100%)
* Minor Failure - Prices increase 20% to 200% (2d10 x 10%)
* Major Success - Prices decrease 10% to 40% (1d4 x 10%)
* Critical Success - Prices decrease 20% to 80% (2d4 x 10%)
Example
Rastia is a campaign area located in temperate hills. The DC for growing food in the area is 11. Circumstance modifiers for the area are -2 (draft animals +2, rocky ground -2, monster activity -2). You roll an 8 on the d20, resulting in a modified roll of 6, which falls in the DC (-1) to (-5) range, a minor failure. This means that there will be minor food shortages in the area and food prices increase 70% (2d10 - 2+5 x 10%). If the price increase for shortages seem too harsh, just remember that the resident at in a typical fantasy world just can?t go down to the local Food Lion and get some hot dogs and mac & cheese!
Level 1
Very general: Uses very large categories, such as food, finished goods, etc. Usually determined once per game year to provide general background for the campaign.
Recommended categories:
* Food
* Raw Materials
* Trade Goods
Recommended DCs and Possible Circumstance Modifiers
Food - including crops, livestock, fish, etc.
-
* Plains/Grasslands (DC 8)
* Light Woods/Low Hills (DC 10)
* Heavy Woods/Highlands (DC 12)
* Swamp/Mountains (DC 14+)
* Simple Tools (-2)
* Draft Animals (+2)
* Iron Plow (+2)
* Bandit/Monster Activity (-2 to -4)
* Crop Rotation (+2)
* Weather (+2 for good, -2 for poor)
Raw Materials (including lumber, stone, gold, silver, iron, etc.)
Note: Typically, the more heavily populated an area is, the more the natural resources and raw materials have been depleted, forcing civilizations to go farther and farther afield to secure raw materials to keep their economies going.
-
* Virgin Wilderness (DC 8)
* Sparsely Populated (DC 10)
* Moderately Populated (DC 12)
* Heavily Populated (DC 14)
* Good Trade Route Nearby, such as a river, road or coastline (+2)
* Manpower pool (from +2 for plentiful to -2 for scarce)
* Bandit/Monster Activity (-2 to -4)
* Simple Tools (-2)
* Advanced Tools (+2)
* Transport System (from +2 for good to -2 for poor)
Trade Goods (including armor, weapons, spell components, wagons, ships, furniture, etc.)
Note: Typically, it is much easier to obtain trade goods easily in heavily populated areas and more difficult in sparsely populated ones, the exact reverse of raw materials.
* Heavily Populated (DC 8)
* Moderately Populated (DC 10)
* Sparsely Populated (DC 12)
* Good Trade Route Nearby, such as a river, road or coastline (+2)
* Manpower pool (from +2 for plentiful to -2 for scarce)
* Bandit/Monster Activity (-2 to -4)
* Simple Tools (-2)
* Advanced Tools (+2)
* Transport System (from +2 for good to -2 for poor)
Level 2
More specific. Works well if you want to add more detail to the campaign without being overly complex. Uses specific categories, such as cattle, horses, grain, gems, gold, silver, wine, etc. For each campaign area, select 2-5 (1d4+1) major industries that the area is known for and assign a modifier (usually in the -2 to +6 range). Your list of trade items and industries should be pertinent to your campaign - "candles" probably shouldn't be a category, but "magic components" might be.
Once per year or trading season, you make a roll for each industry/trade item to see what the supply looks like. You can use shortages and over-supply as good adventure hooks. City A has a severe shortage of silver, but City B has a major surplus. If the PCs can get a shipment from B to A, they will be rich (of course, bandits, rival groups and orc tribes may all try to get the shipment themselves)!
Possible Industries/Trade Items (by no means an exhaustive list):
* Gold
* Silver
* Gems
* Grain
* Fish
* Horses
* Exotic Mounts
* Cattle
* Sheep
* Lumber
* Stone
* Cloth
* Silk
* Wine/Ale
* Armor
* Weapons
* Wagons
* Ships
* Furniture/Tapestries
* Magic Components
* Magic Items
* Mercenary Units
Recommened DCs
This will be highly variable, depending on your game world. I recommend a range for 8 (very routine) to 12 or 14 (very difficult).Don't make the base DC too hard, or no trade would ever get done! You can make it tougher with appropriate circumstance modifiers.
Possible Circumstance Modifiers (in addition to those listed above):
* Guild Relations (from +2 for good to -2 for poor)
* Taxes (from +2 for light to -4 for heavy)
* Government Regulations (from +2 for light to -4 for heavy)
* Peasant Revolt (-2)
* Border Skirmish (-4)
* Open War (-6)
* Recent Famine or Plague (-2 to -6)
Level 3
Very specific. Use if you want to have a detailed economic backdrop that is a major part of the campaign. Develop the industry/trade goods list for the campaign world, then assign a modifier for each area in each industry/trade good. So if you have 5 major countries and 12 industries/trade goods, you would assign a total of 60 modifiers. If you decide an area doesn't or can't produce a category (a desert city is unlikely to produce "fish", for instance), then they have to import it to get it and prices for those goods are likely to be 150% to 500% higher than normal.
If you are using a pseudo-medieval setting, you should also decide which guilds/trading houses/trading families/government institutions control or compete in the various trading areas (remember that the more competition in a given area, the lower the prices usually are).
For each category, determine success or failure. For each point the check exceeds the DC, the industry has the potential for a trading profit, determined by the number of people in the area that work in that industry (and your monetary system). To keep it easy, for basic materials (iron ore, food, lumber,etc), I usally use 1 gp x number of people in the industry x number the check exceeds the DC.
For example, Doria is a mining center, has 500 people working in the mining industry with a total modified DC of 11 for mining iron ore. You roll a 17 on the check. The potential profit is 1 gp x 500 people x 6 or 3,000 gp.
To realize the profit, Doria would need to make a "trading check" (new term - basically representing a trading caravan or trading fleet to move the goods to market). Again, you assign a DC and make the check.
* Regular Success: normal profit (100%).
* Major success (+6 or more over the DC): profit increase by 50% (150%).
* Critical success: profit is multiplied by 1d4+1 (200% to 500%)
* Minor failure: profit decrease by 25% (75%).
* Major failure (-6 or more below the DC): profit decrease by 75% (25%)
* Critical failure: loss of the whole shipment (0%)
The 1 gp per person in the industry works well for abstract items (ore, lumber, etc). For items listed in the PHB or DMG, work this a little differently. Use the industry check to see how much excess is produced (10% for each point above the DC), then mulitply by 1/10 of the item cost to determine potential profit.
For example, Doria also has many excellent dwarven armorsmiths who make superior chain mail. They typically produce 100 suits in a year. The DC for Armorsmithing in Doria is 10 and you roll a 14, so the smiths of Doria have produced 40% more armor this year, or 40 additional chain mail suits. Their potential profit 40 x 15 or 600 gp, subject to a successful trading check.
On the other hand, if an area fails checks for basic materials, like foodstuffs, you can reverse the procedure to see how much the rulers of the area need to fork over to keep their people from starving! I usually use 1 sp per person x the number you roll under the DC.
For example, Doria has a modified DC of 13 for food productin and rolls a 7, a major failure! The city has 8,000 inhabitants, so Doria will need to come up with 48,000 sp, or 4,800 gold, to stave off starvation (1 sp x 8,000 people x 6 below the DC).
Level 3 is really only for those that like to keep a very detailed campaign, but it is fairly easy to set all of this up on Excel spreadsheet and update it once a year. What I do is "net" the profit/costs for each area for the year (using Excel's sum operation). So I will have a good idea if there are going to be extra taxes in the area that year or if a big suplus is cause for a major celebration.
Level 4
Part 1
This level is designed to go down to the micro level and allow PCs to either interact/run a guild/business or to participate in trading caravans/voyages. I will tackle the Guild/Business aspect first.
Guild/Business:
The crafting rules on pp. 65/66 of the PHB are fine for crafting a single item, but what if you have a guild of 10 or 50 craftsmen? The system becomes a bit unwieldy. I recommend using the D20 trade mechanic to speed things up - using the following steps (we will use the Armorsmith's guild of Doria as an example):
(1) Determine the average skill check result for all guild members. Let's assume the Doria's Armorsmith's guild has 25 smiths - 1 grandmaster smith (+13), 3 master smiths (+10), 6 journeymen (+7) andd 15 apprentices (+4). Therefore,the guild's average skill check bonus is +5.8 - which rounds down to 5 (3E convention). Add this to the average d20 roll (10.5 rounded down to 10) for an average skill check number of 15.
(2) Next, multiply the average skill check number x the DC of the item being created. Let's say the the guild is creating chain mail armor (DC 15). 15 x 15 = 225.
(3) Then, divide the cost of the item being created, in silver pieces (chain mail armor, 150 gold = 1,500 silver) by the result from #2 above, resulting in 6.67 - rounded to 6. This is the number of weeks, on average, it takes 1 member of the guild to complete 1 suit of chain mail.
(4) If we are making an annual check, divide 52 weeks (for a standard year) by 6 - 8.67 - which rounds to 8, the average number of suits each guild member can finish in a year. So the Doria Armorsmithing Guild, in an average year, can create 200 (8 suits x 25 guild members) suits of chain mail armor.
(5) Lastly, we use our D20 Trade Mechanic to see how profitable the Guild is for the year. This is their routine craft, so set the base DC to 10. There are no unusual circumstance modifiers. You could, if desired, add in modifiers like:
* low manpower (-2)
* bandit activity (-4)
* cheap iron ore (+2)
* commission from the king (+2)
Assume a base profit of 10% of the item cost, so the guild typically makes 150 silver, or 15 gold on each suit. So if they just made their check, their profit would be 3,000 gold for the year. Since they exceeded the check by 4, their profit was 40% higher, or 4,200 gold!
If the trade check roll had been a 2, then the profit for the year would have only been 2,100 gold.
This may seem like a lot of math and it does take some calculations to get it going, but then you can have a line entry similar to this:
Doria Armorsmithing Guild: (25 members, average skill check 15, base armorsmithing trade check 10, trade check bonus +5)
Let's look at another example, with the following guild:
Opal Shipwright's Guild: (80 members, average skill check 15, base shipwight trade check 12, trade check bonus +5)
Assume you want to know how many warships (p. 151, DMG) they can build in a year and what their profit is.
A warship costs 250,000 silver. Assume the DC for creating a warship is 14. 250,000/210 (ave. skill check 15 x DC 14). The result is 1,190.48 - round to 1,190. It would take 1 guild member 1,190 weeks to build 1 warship! Since we have 80 guild members, assume that all 80 are working on the ship. 1,190/80 is 14.88 - round to 14, so it takes the guild 14 weeks to build one warship.
That means that the guild could build, on average, 3 warships in a year's time (52/14, round down=3). How much profit do they make for the year?
The trade check DC is 12, but there has been a severe wood shortage (-4). The roll is a 10 - resulting in a final trade check of 11, just short of the DC of 12. This means that their profit is 15% below normal. So their total profit is 63,750 silver or 6,375 gold (25,000 silver x 3 warships x .85%).
Part 2
This last part is about how the PCs interact with the Economic System. This can be done several ways.
(1) PC's own a business - Sometimes, the PCs will want to own a business (usually in the crafting area). This is set up very similar to the way a guild is. Let's look at a quick example:
Larethin's Bows - Larethin is a bowyer and the PCs need a legitimate business front (or just want to make extra money). In addition to Larethin (+10 skill check modifier), the shop has one journeyman level bowyer (+7 skill check) and three apprentice level bowyers (+4 skill check).
(NOTE: As a general rule, for every three apprentices, you need a journeyman, for every three journeymen, you need a master and for every three masters, you need a grandmaster).
Since Larethin will be adventuring much of the time, we will need to do two stat blocks for the business, one with Larethin and one without. Our stat blocks look like this:
Larethin present: (Larethin's Bows - 5 members, ave. skill check 15, base bowyer trade check 12, base trade check bonus +5).
Larethin not present: (Larethin's Bows - 4 members, ave. skill check 14, base bowyer trade check 12, base trade check bonus +4).
Clearly, the shop will not be nearly as efficient when Larethin is out adventuring, but can still make some money. Let's assume that they make an equal amount of shortbows and longbows throughout the year (average cost of 525 silver). It takes the average employee 2 weeks (525/15*12, round down) to create a bow if Larethin is present and 3 weeks if he is not (525/14*12, round down).
(NOTE: When the PCs are running a business, it is usually better to do montly checks, as opposed to annual checks)
If Larethin is present, the shop can produce 10 bows (5/2 x 4 weeks, round down), equally split between longbows and shortbows. If he is not present, they can only produce 5 bows 4/3 x 4 weeks, round down), DMs choice on whether the 5th bow is long or short. You would then make the trading check normally, with the average profit per bow being 52.5 silver pieces. In addition, when Larethin is not present, he has to pay an extra 25% of profits to his senior person as an extra management fee!
(2) PCs are actively engaged in assisting the trading caravan/fleet/etc: - This is much more subjective, but in general, PCs with significant skill ranks (not total mods) in particular areas can have a positive impact on a trade mission.
For example, a PC with 5 or more ranks in wilderness lore could lend a +2 circumstance modifier to the trading check an overland trading caravan. A PC with 5 or more ranks in Knowledge: Navigation could do the same for a trading vessel. A PC with 5 or more ranks in Bluff or Diplomacy might be able to assist in trading negotiations, etc. At higher levels, spell casters might be able to enhance a trading check for an entire region (for instance, a high level druid casting a weather spell might add a +2 circumstance modifier to food production checks for an entire city or region).
Finally, you can use the trading check mechanic to pre-plan encounters on a journey instead of randomly determining them (whether or not they are involved in a trading mission). For instance, you determine that the overland journey from Doria to Restia is usually a DC 14. One of the PCs has 6 ranks in wilderness lore, giving a +2 circumstance modifier, but there has been unusually heavy bandit activity in the area, for a -4 circumstance modifier. You roll a 12, which is modified to a 10 (total of -2 circumstance modifier). I recommend that you have 1 encounter for every 2 points under the DC, so this roll would indicate 2 encounters during the journey - which you determine ahead of time instead of rolling for random encounters. Had the roll been 18, then you could just "fast forward" the party to Restia without repetitive rolling for each day of the journey.
Hopefully, you will find the Economic System useful at some level in your campaign
!Best wishes,
~ Old One
