View source for Trading

{{As Of Patch|2.0.201.64}}
The player may '''trade''' with [[NPCs]] in [[{{Gamename}}]]. Trading is closely related to [[commerce]], the base value of items. Most commonly, players will be trading with [[merchants]].

The central currency in Qud is the {{dram}}, a small measure of drinking {{favilink|water}} that must be stored in its own container. For clarity, in this page "$" represents drams in the commercial sense, while drams as the fluid volume is represented as "D".

For methods on making money, see [[Making Money]].

== Overview ==
Trading is initiated by selecting the relevant dialogue choice or pressing tab. Trading can performed by speaking to any character who

# is non-hostile; 
# has items they can trade; 
# is able to communicate with you;
# is within physical range.

Traders benefit by taking significant profits, as [[Trading#Commerce|commerce]] means they have a significantly greater selling prices than the player. The player benefits as '''any''' offer they make will succeed provided they can pay any owed drams and accept any drams they are owed. For example, a {{favilink|scrap-clad hermit}} with only one item to trade will still provide the required payment if you offer him $20,000 of material, but only if you have the capacity to accept 20,000D. Note that NPCs, for the purposes of selling them goods, will have infinite water. The only limit to how many drams can be earned in one transaction is the total volume of liquid that the player can hold.

Commerce rates are affected by multiple factors:

* The [[Attributes#Ego|Ego]] attribute. Higher ego means lower buying prices and higher selling prices.

* Player [[Reputation]] with the trader's [[Factions|Faction]] affects ego in trades. A good/bad standing grants ±1, and a very good/very bad standing grands ±3.

* Certain ego-relevant attributes can also impact trading, either directly (full-onset [[Glotrot]]) or indirectly ([[Socially Repugnant]] mental defect).

* Most items have a variable value, noted in-game with a blue {{drams|$}}. These items are affected by the player's ego and reputation, and prices will vary from trader to trader.

* Few items have a constant value, noted with a golden {{constant|$}}. These items are unaffected by commerce and have a better $/lb value than drams, so they're a very efficient way to carry excess currency.

==Trading UI==
[[File:Trading.png|right|thumb|500px|Trading dialogue]]
The trading screen is separated into two halves: the left half is the character the player is trading with, and the right half is the player's inventory. Here the player can offer to buy the NPC's wares off of them or attempt to offer up their own for {{favilink|water}}.

===Controls===
{| class="wikitable"
! Key
! Purpose
|-
| Esc
| exit trading inteface without an offer
|-
| Left/Right
| navigate between both trading sides
|-
| Up/Down
| scroll through the items on one side
|-
| Tab
| choose to buy/sell the entire inventory
|-
| Enter
| select an entire stack of an item
|-
| -/=
| decrease/increase the amount of items offered in a stack by 1
|-
| o
| offer to complete the trade
|-
| Space
| general interaction menu. Here the player can examine objects, or ask the trader to identify or repair items (if they have the proper skill)
|-
| i
| ask trader to identify an object (can be either in their own inventory or the player's)
|-
| r
| ask trader to repair/recharge an object (can be either in their own inventory or the player's)
|}

==Trading Formula==
{{main|Commerce}}
Caves of Qud has a bartering system where items vary in price based on a multitude of factors. Items do not  have a "set" price like other similar games of the genre. Instead, items all have a commerce value. Commerce is the base value that is specified for each item that is then multiplied or divided by a multiplier depending on selling or buying. 

This multiplier depends on the player's [[Ego]] modifier as well a few other factors, such as the [[Snake Oiler]] skill.

=== Trading Formula Details ===
{{Excerpt|Commerce#Trading Multiplier Formula}}

== Economy ==
=== Drams ===
The central currency to the game is {{favilink|water|fresh water}}, often simply referred to as their measurement {{dram}}. 1D of water is universally valued at {{drams|$}}1, and is used to pay any outstanding difference in transactions: if the player offers $32 of material for $35 of material they are required to throw in 3D to cover the outstanding $3 debt. Only fresh water is accepted as balancing currency: if the water is contaminated by any other liquids then it ceases to be counted as drams unless it can be purified.

It is important to note that dram exchange requires appropriate space:

* First, any containers of fresh water will be poured into until full.

* If the container fills then excess drams will be poured into the next fresh water container with space.

* If there are no more fresh water containers then excess drams will pour into the next empty container.

* If all water containers are filled and there are no acceptable containers then the trade will be rejected.

Drams '''will not''' go into containers filled with anything but fresh water, as it will cease to be currency of the same value once mixed. Lacking space for owed credit or drams for owed debt will result in the transaction being rejected.

===Balancing Bias===
While exchange prices have three decimal places of accuracy, the amount paid will round to the nearest integer. In such cases the bias always favors the trader: 

{| class="wikitable"
! Trader Value
! Player Value
! Difference
! Balance
|-
| -$112
| $208
| -$112 + $208 = +$96
| Merchant pays 96D
|-
| -$32.75
| $45.33
| -$32.75 + $45.33 = +$12.58
| Merchant pays 12D
|-
| -$500
| $500.999
| -$500 + $500.999 = +$0.999
| Merchant pays 0D
|-
| -$130
| $87
| -$130 + $87 = -$43
| Player pays 43D
|-
| -$74.308
| $62.079
| -$74.308 + $62.079 = -$12.229
| Player pays 13D
|-
| -$145.001
| $145
| -$145.001 + $145 = -$0.001
| Player pays 1D
|}

=== Alternatives ===

4 drams of any liquid weighs 1lb, so the weight of a filled container is the capacity divided by 4; an empty 64D water skin weighs 1lb but the same one filled will weigh 17lbs, as '''64D / 4 = +16lbs'''. While an acceptable cost early on, drams will slowly start to eat into your carrying capacity as you find more liquid containers and start selling loot, so materials with higher guaranteed $/lb will eventually become necessary. It should be noted that it is still strongly advised that the player keep one or two water containers with space so that owed currency can still be easily managed between transactions.

==== Liquids ====

Water is not the only liquid that can be traded; unlike drams, they cannot be automatically poured. Liquids other than fresh water must be sold with the container as added value, so the actual profit is '''(Drams * 1D Value) + (Sold Container Profit - Replacement Container Cost)'''. For example, 64D of honey always sells for $128 ($2/D), but to sell it you first need to put it in a $3 {{favilink|Canteen}} which gets you a total of $131; if canteens sell for $3 then they cost $8.574 to buy with base stats, so the final profit is $122.

Note that this table simply provides the minimum value for a container of the appropriate size, as factors like player trading stats cannot be accounted for. Liquids with a trading value of $0 are not listed such as {{favilink|Asphalt}} and {{favilink|Putrescence}}. Liquids also have varying weights, so their value per pound will depend.

{{liquid weight to value table}}

==== Trade Goods ====
{{Main|Trade goods}}
Trade goods are effectively non-liquid (figuratively and literally) financial assets. While this does free up skins and can end up lighter overall, they can only be returned to $/D value by selling them to traders. This can cause issues in some cases, as high value items require you to either trade for a lot of items or be prepared to accept a lot of drams. Additionally, dormant items carried for value do not quench [[thirst]] nor can they provide additional uses like {{favilink|lava}}. As such, it can be important to not convert all drams into trade goods.

{{#cargo_query:table=GeneralData=GD, ExtraInfo=EI
| join on=GD.JoinKey=EI.JoinKey
| fields = CONCAT("{{favilink id{{!}}", GD.ObjectID, "}}") = Item, CONCAT(CASE
  WHEN Weight > 1
  THEN CONCAT(Commerce/Weight,"<i>(",Commerce, "/", Weight, ")</i>†")
  ELSE Commerce/Weight
  END) = Value<br />($/1lb)
| where=categories = "Trade Goods" AND EI.Info LIKE '%Currency,,,%'
| order by= FLOOR(Commerce/Weight)
}}
''† Ingots weigh 5lbs''

There are also trade goods that do not keep their prices static across trades:
{{#cargo_query:tables=GeneralData=GD,ExtraInfo=EI
|join on=GD.JoinKey=EI.JoinKey
|fields=CONCAT('{{((}}favilink page{{!}}', GD._pageName, '{{))}}')=Trade Good, GD.Commerce= Value
|where=GD.categories='Trade Goods' AND (EI.Info NOT LIKE '%Currency,,,%' OR EI.Info IS NULL)
|order by=GD.Commerce,GD._pageName}}

== Notes ==
* Purchasing the last tradable item in a character's inventory will result in the trade screen exiting, becoming unavailable until they regain a tradable item. Bear this in mind if you're trying to offload plunder onto a common NPC, as emptying their inventory means they won't engage in any more trade.
* Trade is possible through {{favilink|telepathy}} but only from within physical range. This allows players with [[glotrot]] to exchange goods without finding a cure, though it won't remedy the trading penalties it incurs.
* As long as communication is possible (a dialogue box appears, not whether they appear to understand) and they have an item in their inventory, anybody can be traded with, including non-humanoids.
** {{favilink|Young ivory|plural}}, {{favilink|lurking beth|plural}}, and {{favilink|baetyl|plural}} cannot be traded with and cannot be given items. This is because they do not inherit from the game objects that come with the <code>Inventory</code> part; They are <code>Creature</code>, <code>MutatedFungus</code>, <code>MutatedPlant</code>, or <code>Table</code>.

[[Category:Mechanics]]