Royal resources, namely iron ore, coal, olive oil and glass

<p>Besides wood, stone and food, Empire has a second economic layer: <strong>royal resources</strong>. Each of the main kingdoms owns exactly one - the Empire has iron ore, Norlandia has coal, Sandy Wastes has olive oil and Fire Peaks has glass. You can only produce each one where it belongs, for a long time they mainly serve as trade goods in the villages, and from <strong>level 70</strong> onward they become a mandatory currency for legendary buildings. This article sums up what each resource does, where to get it and how to get it to wherever you actually need it.</p>

Four resources, four kingdoms

A royal resource is a resource tied to one specific kingdom. You can't produce it anywhere else: you can only build a Glass Furnace in Fire Peaks, an Olive Grove only in Sandy Wastes, a Coal Mine only in Norlandia, and an Iron Mine only in the Empire. Each of these buildings has exactly one allowed kingdom hard-coded into the game data.

They unlock one by one as you level up and open new maps. You'll meet coal first and iron ore last.

Fifth in line is Aquamarine from Storm Islands, but it doesn't really belong in this group - it isn't produced in any building and you can't build anything with it.

How each resource is produced

Coal, oil and glass all follow exactly the same production curve. The base building has eleven levels and produces 13 units per hour at level 1, rising to 63 at level 11, so plus five per level. All three take up a 5x5 plot. They only differ in cost and unlock timing: the Coal Mine costs 1 815 wood and 2 144 stone, the Olive Grove already costs 11 652 wood and 14 484 stone, and the Glass Furnace costs 16 449 wood and 22 450 stone.

The Iron Mine is a different case. It doesn't unlock until level 70, but it comes with a full thirty levels and production ranging from 9 to 67 units per hour, by two per level. It costs 10 838 wood and 12 219 stone to build, but the build time is significantly longer than for the other buildings.

Each resource has one multiplier building, of which you're allowed exactly one per castle. It doesn't produce anything itself, it just raises the output of all the relevant production buildings by a percentage. The Coal Refinery, Olive Press and Glassworks all have five levels and add +10 % per level, up to +50 %. The Ironworks has ten levels, but a smaller step: +3 % per level, +30 % total. All four multipliers take up a large 6x9 plot, so they're only worth it once you already have several production buildings on that castle for the percentage to actually apply to.

Watch out for two catches. You won't unlock the Coal Mine until you've upgraded the Home Village to level 1. And in Norlandia, only two buildings of each type (Coal Mine, farm, lumberjack's hut, quarry) run at full 100 % output - every additional one runs at reduced productivity, which you have to make up for with public order and research.

What royal resources are good for

What you use them for changes depending on how far along you are. Up to roughly level 70, coal, oil and glass mainly work as currency in the royal villages. In the Home Village in Norlandia you trade coal for coins, rubies, troops and even the unique castellan gear Frozen Guard's Plate Armor; the villages in Sandy Wastes and Fire Peaks work the same way for oil and glass. The higher you upgrade the village, the better offers you unlock.

From legendary levels (70+) onward, though, the role flips. Royal resources stop being a bonus and become a mandatory line item in your budget. In the game data, iron ore shows up in the cost of roughly 365 building items, glass in 388, oil in 387 and coal in 386 - spanning legendary buildings, districts and wall upgrades alike. Individual amounts range from a few hundred units up to roughly 81 000 pieces for a single building.

The clearest example is the Relic Enchanter, available right from legendary level 1: it needs all four resources at once and doubles the cost with every level - 5 000 of each at level 1, then 10 000, 20 000, 40 000 and finally 80 000 of each of the four resources at level 5. Ore and glass also show up in the cost of upgraded moats; the basic moat at legendary level 65 costs 52 716 wood, 56 491 stone, 51 482 glass and 51 754 iron ore.

The practical consequence: anyone who builds nothing in the side kingdoms hits a wall at level 70. Ore from the Empire alone only covers a fraction of what legendary buildings demand.

Moving resources between kingdoms and the losses involved

For a long time, a royal resource stays exactly where it was produced. Only at level 70 do you unlock the ability to transport it to other kingdoms - which is precisely why level 70 counts as the turning point from which it makes sense to build up production on all maps at once.

But transport isn't free. Part of the shipment gets eaten up as travel cost along the way, just like with wood, stone and food:

So out of every 10 000 coal sent from Norlandia to the Empire, only 7 500 actually arrives. If you're building in your main castle in the Empire, plan from the start that you need to produce roughly a third more than the building's listed cost. Moving resources between kingdoms also takes hours, which you can shorten with research and time skips.

Sensible logistics are therefore simple: build where you produce the resource, and only ship the rest. The most expensive approach is stockpiling everything in the Empire.

Where to loot resources without waiting on production

Your own production is slow, and attacks will reliably outpace it. Every kingdom has its own targets that drop exactly its resource.

Iron Ore can be looted from the Mercenary Camp, from high-level Foreign Castles and Blood Crow castles, from Nomad and Samurai Camps, from other lords' castles that hold ore, and from Robber Baron castles from level 10 upward.

Coal is looted in Norlandia - from Barbarian Towers and Fortresses, and from other players' castles. From level 70 onward, Foreign Castles and Blood Crow castles join in too. You'll also find it in chests from wall expansions on your Norlandia castle, and in small amounts at the Mercenary Camp, usually in an epic offer or occasionally even a free one.

Olive Oil drops from Desert Towers in Sandy Wastes and from resource villages. You get Glass by raiding Cultist Towers in Fire Peaks, which are the local equivalent of Robber Barons.

So before you build another production building, check first what can be looted in that kingdom - it's often a faster route to the amount you need.