One caffeine-filled evening later, I have managed to produce a sort-of Trade Route system with caravans and Profit calculations.
PROVINCIAL IMPROVEMENTS:
Tea Plantation (800 Coins):
Generates 300 Coins per Turn (no Workshop required). Can only be built in Grassland (excluding Capital) and Mountain Provinces.
Bazaar (500 Coins):
Allows commission of Caravans. Boosts incoming Trade Routes' Profit by 50%.
RELIGIONS:
Extra passive bonus for Buddhism: Reduces Tea Plantation Purchase Costs by 20%.
CARAVANS:
For 500 Coins, you can commission a Caravan at the Bazaar, and send it to a neighbouring state to sell some stuff. You can sell both raw materials as well as after-Workshop processed goods (if you have a Workshop, that's it).
Caravans, just like Armies, travel 1 Province per 1 Turn. Once they reach their destination, they are decomissioned and a trade route is established.
There is a limit on amount of Trade Routes you can have, equal to 2 Trade Routes per each Capital Province you control.
At the lowest, the amount of coin you get - called 'Profit' - would be the resources' monetary value, making the point of trading moot. Fortunately, there are some bonus modifiers.
If the targeted Warlord's Province has no access to this particular good (Province 'flavor' not available), the Profit is boosted by 125%.
If the targeted Warlord's Province has access to this particular good but doesn't produce it, the Profit is boosted by 75%.
If the targeted Warlord's Province has access to and produces that particular good, the Profit is boosted by 25%.
If the destination Province is Capital Province, the Profit is boosted by 50%.
If the destination Province has a Bazaar, the Profit is boosted by 50%.
Unfortunately there is one small obstacle; the targeted Warlord must agree to the trade AND is allowed to take a cut to your Profits.
While they can be generous and give you up to 100% Profit, they can demand to be given as much as 50% of the Profit. This 'tax cut' can be adjusted in increments of 10%.
BE CAREFUL: Other Warlords can PILLAGE the Caravan with an Army, destroying it and stealing 500 Coins (Caravan's cost) from you.
Every Warlord whose lands the Trade Route goes through but does NOT end at, is allowed to demand a 100 Coin 'passage fee'. Whether they demand it or not of course depends on them.
The trade routes can be cancelled at any time by either of the two Warlords participating in the trade, as well as by ANY Warlord through whose land the trade route passes through.
Example of Caravan trade (please refer to standard Map of Han for this):
You produce Copper at Western Qin, which is then processed at Workshop in your Capital Province. You've sent this processed Copper to Yan Capital Province, through the lands of Wei, who wants 100 Coins of passage fee.
The Yan can produce Copper at its own Mountains in Southern Yan, but doesn't (for whatever reason), and has a Bazaar Improvement at its Capital Province.
This means that your Profit bonuses would be +75% from access but no production, +50% from Capital Province and +50% from Bazaar present = +175% Profit.
Workshop-refined Copper sells for 300 Coins, so by selling it to Yan Warlord, you can gain (300 + (300 x 1.75) = 825 Coins, of which Yan Warlord demands a 30% Tax cut.
Thus, you receive 577 Coins from selling Workshop-refined Copper to Yan Warlord, who takes 247 Coins of Tax for it, and don't forget the passage fee of 100 Coins for the Warlord of Wei.
Different example; Workshop-processed Lacquer from Song, to Central Wei with Bazaar, via lands of Shu:
Base Workshop-processed Lacquer price: 700
Total Profit Bonus: +225% (no access, Capital Province, Bazaar present):
Tax Cut for Wei Warlord: 40%
Passage Fee for Shu: 100 Coins
Coins earned: 2275 - (40% Tax) = 1365 - (100 Coins for Shu) = 1265 Coins earned from trade with Wei.
Another quick example; Tea from Qin to North Shu:
Base Tea price: 300
Total Profit Bonus: +175% (no access, Bazaar present):
Tax Cut for Shu Warlord: 20%
Coins earned: 825 - (20% Tax) = 660 Coins earned from trade with Shu.
1. Does Tea feel like a filler, or is a welcome add-on?
2. What do you think about Trade Route/Caravan system? Is it chaotic or looks fiddly to use, or maybe is OK?
3. Most importantly: