贸易品

Trade goods come in a wide variety of types, with 34 different trade goods divided into 6 categories. They allow you to tailor your provinces, and even more so your country, to your needs and desires by controlling what you produce and where you ship it, and are particularly important.

Mechanics

Production

Every territory produces one type of trade good, and all territories in a province contribute their trade goods into a common pool. A territory produces 1 trade good by default (with 2 for cities and 3 for a metropolis), but can produce more with enough slave labor. For each additional 15 slaves in a settlement and 20 slaves in a city or metropolis (rounded down), the territory will produce one more additional trade good.

The threshold for a surplus is reduced for each territory by the Slaves needed for Local Surplus modifier, and across all territories in the country by the Slaves needed for Surplus modifier. Sources of these modifiers include:

• -2 by the "Land Seizure Protocol" Land Reforms Law (Requires Civic Advances level 12)
• -1 by the level 7 Slave Latifundia Civic Invention
• -2 by farmland terrain type
• -5 by a farming settlement or a mine

Some territories also have unique permanent modifiers giving surplus threshold reductions, such as the Rhodian Glass Workshops in Rhodes or the Cedars of the Gods in Phoenicia.

Additionally, the Base Resource Production modifier increases the base number of trade goods produced regardless of the number of slaves in the territory. The most important sources of base resource production are cities and metropolises, which give +1 and +2 base resource production, respectively. This means that cities are still a significant source of trade good surpluses even without the high slave ratios and slaves needed for local surplus modifiers that settlements and their buildings give.

Surpluses and trade

主条目：Trade

A province will have a trade good surplus if it produces more than one of a certain trade good, either because it has more than one territory producing the same trade good and/or if its territories have enough slaves to produce multiple resources in the territory. A surplus typically gives no inherent bonus except for the stacking base trade good bonus; the main use of surplus trade goods is to trade them away to other provinces for commerce income, as well as to move the location (and bonuses) of the resource to another province. Imported trade goods contribute to the trade good surplus just like locally produced trade goods, while resources that are exported no longer give their effects to their province of origin.

Each trade good as a certain Base Trade Value that determines the amount of income countries receive from trading the resource. Trading common resources like grain or furs will give much less gold than valuable, exotic goods like dyes or gemstones. For foreign trades (i.e. between provinces belonging to different countries), the exporting province will receive the full base trade value, modified by the country's export value, in commerce income, while the importing province will receive 0.35 times the base trade value in commerce income, modified by the country's import value. Domestic trades will instead give only 0.20 times the base trade value for both the importing and exporting provinces. Areas that can produce and export valuable trade goods are therefore generally richer and more lucrative to conquer, but making sure that there are available trade partners is also important.

Trade route requests can only be initiated by the potential importer. Countries hoping to export resources should instead focus on making sure as many surplus trade goods are available as possible and if necessary make sure there are enough potential trading partners in diplomatic range, and then wait for trade requests to come in (which generally does not take too long).

Bonuses and effects

Each individual trade good has a particular bonus that is applied to their province, which stacks based on how many instances of the resource is present. Each category of trade goods has a different set of bonuses - military trade goods allow recruitment of the more specialized unit types as well as giving a small output or resource bonus, food trade goods increase the available in the province, and trade goods in each of the pop type categories increase the local happiness of the corresponding class. These bonuses can grow to be quite significant for large and prosperous provinces that produce and import many different trade goods, and are particularly important for providing the food necessary for more urbanized provinces that have long since outstripped their limited local food supply, as well as increasing the happiness of the normally restive nobles and citizens who produce most of the research points and trade routes in the country.

Each trade good that has a surplus in the capital province specifically also gives a special nationwide bonus. Unlike the normal province modifier, this bonus is not stackable and is only applied once per trade good, which means that it is generally better to have a large variety of surplus resources in the capital to accumulate as many bonuses as possible. As the capital province is likely to be the most populous province in any case with the most higher-class pops, it is almost always better to focus on accumulating trade good bonuses in the capital above every other province.

Changing trade goods

In general, trade goods cannot be changed directly by the player. Trade goods can, however, be changed indirectly with the foundation of a city. Agricultural trade goods ( grain, fish, livestock, and vegetables) can only be produced in settlements; founding a city on a food-producing territory will replace the trade good once the city is finished, typically with a higher value Nobles or Citizens trade good. The probability can be seen by hovering over the "Found a City" button at the "build" options panel. If the city status is later revoked, the territory will revert to producing its old agricultural trade good. Note that this applies only for cities founded during the game - revoking city status of a city that already exists at start will not change the trade good.

The trade good of a settlement can also be changed by a few special events and missions, most notably the prospecting task of the generic infrastructure mission.

Goods list

Strategic resources

Trade good	Province modifier	Capital surplus	Base trade value	Description
Iron	Allows Heavy infantry +2% Local tax	+10% Heavy infantry discipline	0.30	The presence of iron-working defines many cultures. Vastly superior in strength to its predecessor, bronze, iron is unparalleled as a material for tools and weaponry alike.
Horses	Allows Heavy cavalry Allows Light cavalry +1% Population Output	+10% Heavy Cavalry discipline	0.25	The use of horses in agriculture and warfare is widespread. As beasts of burden, they are well suited to drawing chariots, as well as carrying riders.
Wood	Allows Hexere Allows Tetrere Allows Octere Allows Mega-Polyreme +2% Local manpower	+25% Ship recruit speed	0.20	Widely used in construction and shipping, decent timber can command a high price in unforested areas.
Elephants	Allows War elephants +3% Population Output	+10% War elephant discipline	0.30	Like many beasts of burden, elephants have been used for agricultural, religious and military purposes since their domestication. Many civilizations regard the elephant as a sacred or revered creature.
Steppe horses	Allows Horse archers +1% Population Output	+10% Horse Archer discipline	0.25	Steppe horses, while often smaller and stockier than their western counterparts, are more suited for their life in the arid terrain of the steppe.
Camels	Allows Camel cavalry +2% Province commerce	+10% Camel discipline	0.25	Used extensively as beasts of burden and warfare, camels are adept at surviving in harsh, arid climates.

Food

Trade good	Province modifier	Capital surplus	Base trade value	Description
Grain	+5 Local monthly food	+5% Global monthly food modifier	0.20	Grain has long been a staple part of the human diet. Refined into flour, and subsequently bread, the farming of grain provides the vast majority of the food supply for many nations.
Salt	+3% Local monthly food modifier	−5% Army maintenance cost	0.30	Greatly valued as a food additive and preservation agent, salt is in such high demand that it often serves as a parallel currency.
Fish	+3 Local monthly food	+8% National freeman happiness	0.20	Fish provide a staple part of the diet and economy of every coastal civilization in the world.
Livestock	+3 Local monthly food	+25% Pop promotion speed	0.30	Encompassing a multitude of domesticated animals, livestock provides numerous goods such as milk, cheese, meat and wool, which drive a significant part of the economy.
Honey	+3% Local monthly food modifier	+3 Diplomatic reputation	0.40	Although domestic beekeeping is not widespread, honey is highly sought after as a foodstuff and preservative.
Vegetables	+3% Local monthly food modifier	−25% Move slaves cost	0.20	Nuts, seeds, pulses and vegetables are gathered by foragers and subsistence farmers across the world.

Nobles

Trade good	Province modifier	Capital surplus	Base trade value	Description
Papyrus	+4% Local noble happiness	+5% Civic tech investment	0.45	Most of the civilized world uses wax tablets, etchings, and stone carvings to store the written word. Papyrus, however, which is uniquely produced in the Egyptian region, offers much greater ease of access and use.
Cloth	+4% Local noble happiness	+5% Oratory tech investment	0.35	Cloth can be produced from numerous plant or animal products, and is found, in varying quality, at markets throughout the known world.
Dyes	+4% Local noble happiness	+8% National noble happiness	0.45	Expensive dyes such as Tyrian purple and kermes are harvested from rare invertebrates in very localized habitats. These colors are particularly sought after by the ruling elite of many cultures, and are bound to command a high price.
Marble	+4% Local noble happiness	−0.01 Monthly tyranny	0.35	Due to its softness and lustrous hue, marble is regarded as the prime material with which to sculpt statues and icons.
Incense	+4% Local noble happiness	+5% State religion happiness	0.45	The term 'Incense' covers an array of rare, exotic substances which are primarily used for religious purposes.
Silk	+4% Local noble happiness	+3% Local noble output	0.40	Shrouded in mystery, the origins of silk cultivation lie in the far east. This exotic fabric is rare enough to command great interest, and an even greater price.

Citizens

Trade good	Province modifier	Capital surplus	Base trade value	Description
Amber	+4% Local citizen happiness	+0.05 Monthly ruler popularity gain	0.50	Formed from the resin of pine trees, the appeal of amber as a decorative material, combined with its scarcity, results in a particularly valuable commodity.
Spices	+4% Local citizen happiness	+3% National citizen output	0.45	Primarily used as food additives, the many herbs which comprise the spice trade command a variable price depending on their provenance.
Precious metals	+4% Local citizen happiness	+8% National citizen happiness	0.50	Gold and silver have been regarded as a measure of relative value since the minting of coins began. The history of gold as a commodity is deeply intertwined with its use in religious and mythological imagery.
Earthenware	+4% Local citizen happiness	+3% National freeman output	0.35	The production of earthenware has been a defining activity of human civilization since the discovery of fire. Earthenware encompasses practical utensils such as bowls and jugs, as well as statues, urns and other decorative items.
Gemstones	+4% Local citizen happiness	+5% Country civilization level	0.50	Highly prized as ornamental items, the incredible rarity of gemstones ensures that only the most wealthy will ever possess them.
Glass	+4% Local citizen happiness	+5% Country civilization level	0.40	The production of glass not being widespread, has a great effect on its value as a commodity. Glass beads, decorations and even urns are in high demand throughout the known world.

Freemen

Trade good	Province modifier	Capital surplus	Base trade value	Description
Wine	+4% Local freeman happiness	−5% Army maintenance cost	0.30	Wine is produced from grapes, raisins and many other fruits, and has myriad uses in recreational, religious, and cultural pursuits. The wine trade is an important part of the Mediterranean economy.
Leather	+4% Local freeman happiness	+10% Light infantry defense	0.20	Tanned hides have numerous applications in domestic and military life. Early shields were often leather clad, softening the blow of any incoming strikes.
Base metals	+4% Local freeman happiness	+10% Light infantry offense	0.35	Copper, Tin and Lead, whilst unsuitable for military purposes, have long been used in alloying and decoration. Although used ubiquitously, the relative geographical scarcity of these metals results in them commanding high prices throughout the world.
Hemp	+4% Local freeman happiness	+10% Ship damage done	0.25	Cultivated from time immemorial, hemp has been instrumental in the development of clothing and ropes, due to its fibrous nature.
Dates	+4% Local freeman happiness	+5% National commerce income	0.30	Primarily cultivated in warmer climes, date products are a staple part of the diet in many cultures.

Slaves & Tribesmen

Trade good	Province modifier	Capital surplus	Base trade value	Description
Stone	+4% Local slave happiness	−10% Build cost	0.25	Whereas wood will often suffice as a building material for temporary or cheap structures, only stone can yield the kind of permanence desired in a fine civic building or enduring defensive bastion.
Wild game	+4% Local tribesman happiness	+10% Archers discipline	0.20	Since the early days of humanity, hunter-gatherers have regarded wild creatures as a primary source of nourishment. Fine meat is often hard to come by, and can result in a particularly lucrative trade.
Furs	+4% Local tribesman happiness	-0.50% Experience decay	0.20	Furs have been used since time immemorial to shield humans from the biting cold. Ranging from stitched rabbit skins to great bear hides, a good fur can be put to any number of uses.
Olives	+4% Local slave happiness	+8% National slave happiness	0.25	Cultivated for millennia, olive products drive a significant part of the Mediterranean economy. Many cultures value the olive as a symbol of fertility and power.
Woad	+4% Local tribesman happiness	+8% National tribesman happiness	0.35	Woad, as well as various other simple dyes, can be refined from the petals of certain wild flowers. Many cultures practice ritual body-painting, as well as the creation of painted iconography, using these colors.

Strategy

Strategic resources

Resources of this category grant mainly military bonuses, advantages or features. The production of cavalry in a province is linked to the availability of horses within that province, while the production of ships in a province is linked to the availability of wood within that province. Any lack of a strategic resource leads to a lack of a certain unit or advantage that may force the player to adapt his military strategy.

Pop happiness

Use provincial trade routes to import goods to increase a pop type's happiness within the province. This works best in provinces with large numbers of the pop type.

Note the trade goods which increase happiness at the state level when the capital has a surplus:

• Slaves: Olives
• Tribesmen: Woad
• Freemen: Fish
• Citizen: Precious metals
• Nobles: Dyes

Food

Food resources in a province help feed the pops of the province. If there is a surplus of food (food within the province, not as a resource for national or international trade), the pop growth rate increases. A lack of food leads to a decrease in pops and their happiness. Any lack of food can be prevented, by importing a food surplus from one province to a starving one. Any 1 surplus of a food resource within a province can be transferred within the player's nation by using 1 trade route.

Also, since creating a city removes Food-type Trade Goods from the settlement, such settlements should not be chosen to locate cities.

Military

Military resources affect the quality of units and bonuses of military structures like forts. This type of resource does not change the variety of units the player's nation can build, but it does affect stats and advantages of produced units. Strategic resources should be preferred to military resources: With a hemp surplus in the capital, the ship damage increases about +10%, but missing wood leads to the incapability of building ships and of using the hemp-given advantage of additional damage.

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