(by nasenbaer)
see https://blueprints.launchpad.net/widelands/+spec/trade-system

(by sirver)
Setting to incomplete for bug sweeping.

(by wl-zocker)
I think trading will be a great addition to the game. It supports the interaction of players (one can help another one) and it adds a peaceful component.
I prefer the way trading should work described in this bug report (first make a deal, then transport the wares) to the way described in the blueprint (trader travelling around and hoping to get his wares sold, which seems like a lot of luck to me).
Of course, there are some obstacles that have to be dealt with: What happens when two different tribes want to trade? How will the AI deal with trading offers/will it make own ones?
I feel this will change gameplay a lot, maybe similar to how seafaring did.

(by sirver)
I agree. I also think this bugs suggestion is better than the blueprint.

However, to represent the traded wares in game, it would be beneficial to merge the tribes. Otherwise, everything will be very convoluted and error prone code wise.

(by sirver)
Setting to incomplete for bug sweeping.

(by tiborb95)
I was thinking a bit about this, so my opinion
Trading post would be the type of warehouse, where you would have arrows indicating:

• selling
• buying
• or no arrows
  Only items for sale would be stored there

I think we would need a currency and clearing systems - yes, it sounds strange, but my idea is:

• it would be very complicated to set up barter ratio for all pairs of goods to be traded, single price for ware typ would be better.
• also the barters would not take place in the very same time, or there is possibility of small (im)ballance, f.e. you change one gold in price of 5, for two irons with price 2 each, and there will be ballance of 1 something left.
• Each player would be allowed to set a credit to other players - quite minimal, or bigger if he wish, just to smooth out those small differences in prices.

Trading post would have something like "portdock", where the trader of the other tribe drops the fetched ware. Or rather is should immediately be transported into warehouse.

Each trader would only carry ware from own trading post, so not taking another ware back, this would be the task for the other trader.

So production program for trader could look like

• find other player trading posts in some radius
• Find what they requires
• do we have such ware in the trading post? If yes:
• do our credit to that player allows the selling it to the other player? If yes:
• carry it and drop at other players trading post, swift/clearing system will increase the ballance accordingly

(by tiborb95)
Alternatively we could invent coins, new building mint, coins to be produced from gold or iron perhpas and these could be used for trading... Trader carrying the ware would bring back the coins

(by ypopezios)
For Widelands' style, I would prefer avoiding any type of direct currency exchange. Each player could instead increment/decrement a value for each type of ware like this:

• Yellow neutral symbol (default value, internally 0), meaning not-up-for-trading.
• Green positive value (internally > 0), meaning how much he needs (is willing to pay for) this type of ware.
• Red positive value (internally < 0), meaning how much he asks for selling this type of ware.

And then the system could automatically match the exchange of wares of multiple types in a single trading action whenever a carrier/trader is available for a transfer. Could also present the current lower values in the global economy, for the user to decide if he wants to match any of them.

(by gunchleoc)
We have a prototype market building that's not fully implemented yet. It sends carrier2 to another market building, so I expect the setting will be which wares you can spare and which wares you want.

(by ypopezios)
It's not enough to set those wares, we also need to set their relative values.

Branch: https://github.com/widelands/widelands/tree/market2

Assigned to Nordfriese