Dust

Dust is a FIDSI resource used by all empires to purchase items in the marketplace, buy out city production, and maintain units, heroes, and city improvements.

A few factions have unique interactions with Dust:
 * The Broken Lords cannot use  Food, and their units do not passively regenerate health due to their "Appetite for Dust" trait. Instead,  is purchased with Dust, and Dust must be spent to heal units. The Broken Lords also get +1  on terrain with Dust due to their "Dust Efficient" trait.
 * The Roving Clans receive 8%  of all transactions on the Marketplace from other empires due to their "Cuts Both Ways" trait.
 * The Forgotten cannot use  Science, and can instead purchase technologies with Dust due to their "Science Phobic" trait.

Basic Terrain
Of the basic terrain types, Sea and Lake tiles provide the highest boost to Dust, providing 2 on a tile. Arid tiles are the next best, with the Dirt Field and Sand Dunes tiles providing 2, and the Dry Soil, Snow, and Snowy Field tiles providing 1. Plains tiles tend to provide 1, except for the Grassland and Red Soil tiles which provide no Dust. Among Forest tiles, Savanna provides 1, and with Rock tiles, Sandstone and Tundra Rocks provide 1 each. Among Volcanic tiles, Ash Drifts and Barren Soil each provide 2.

Additionally, tiles with a Luxury Resource deposit on them have a bonus +1.

Anomalies
Anomalies on a tile provide an additional bonus to its FIDSI output, and there are a number of anomalies that provide a bonus of 2, 4, 6, or even 8 on a tile.
 * 2 : Chromatic Land, Clay, Crystal Flowers, Dragon Tree, Hidden Springs, Mutant Marsh, Oasis, Rumbling Stones, Stasis Pillar, Steel Stalks
 * 4 : Black Dust, Caldera Lake, Earthspine, Escaped Specimens, Lava Chimneys, Ruby Cactus Fields, Salt Desert
 * 6 : Weaver Worms
 * 8 : Golden Tree

City Improvements
This list includes any City Improvement that increases a city's Dust output, even indirectly. Some of the improvements listed have additional effects that do not affect Dust production, but for simplicity those effects are not listed.

Expansions
Again, while many of these expansions have other effects, only those affecting Dust production have been listed.

Trade Routes
Trade Routes passively produce Dust and Science, but require some work to establish. The first step in creating trade routes is to research Imperial Highways or Cargo Docks. These technologies allow the Right of Way or Cargo Docks improvements to be built, which allow cities to be connected by land or by sea respectively. Two cities are connected by land if they are in adjacent regions and have both built the Right of Way improvement. Two cities are connected by sea if they border the same ocean and have both built the Cargo Docks improvement in that ocean. Additionally, if two cities are connected by land or by sea to a third city, then they are also connected themselves. This means that two cities may be connected via a complicated series of alternating land and sea routes.

Further details on how Trade Routes work and how to improve them can be found on the Trade Routes page.

Approval
Unlike Food and Industry where a given city's approval affects production in only that city, the overall approval of the empire affects the production of Dust in all cities equally.

Heroes
Heroes provide a number of ways to increase the Dust output of a city they are the governor of, whether that be through capacities, skills, or accessories.

Accessories
All listed accessories are Tomes.

Arcana
The Ardent Mages are able to research the Arcana of Materializing technology, which unlocks the Pillar of Extraction for placement. This pillar increase the Dust output of tiles within range depending on the Arcana level as shown here: Upon obtaining the Cold Engineering technology by completing Chapter 5, Part 1 of the Ardent Mages faction quest, the Pillar of Extraction will produce an additional +3 on tiles within range during winter.

Assimilation
The Delvers provide an assimilation bonus of +5% on cities per pacified and rebuilt village, up to +30%.

Empire Plan
The Economy and Population branch generally serves to increase the production of Dust or reduce the cost of using it, but the Tier 1 and Tier 4 effects directly increase Dust output. Tier 1 grants +3 per  on cities, and Tier 4 provides +25%  on cities.

Fortresses
Different parts of oceanic Fortresses provide different amounts of Dust income. Between the three Citadels, Bastions provide 1 and Manufactoriums provide 2, while Listening Posts provide no Dust.

Among the other facilities that make up the parts of a Fortress extending off the Citadel, the following provide additional Dust:
 * Luxury Resource Facilities: +1
 * Vile Tide Facility: +8
 * Sky-Shaker Facility: +10
 * Dust Accumulator Facility: +10, +2% per Fortress on empire.

Pillaging
Pillaging regional buildings - such as resource extractors and pacified villages - provides a variable amount of Dust upon completion in addition to other rewards. The Forgotten can increase the amount of Dust gained from pillage further via their faction technology Dust Sense.

Resource Boosters
A number of Luxury resources (and Strategic resources for the Vaulters and Mezari) can be used to increase empire-wide Dust production.

Ruins
Searching ruins has a chance to produce a reward, the most common reward being an amount of Dust.

Technology
There are only two technologies that directly increase an empire's Dust production. The first is Dust Crematorium, a technology unique to the Broken Lords which provides 1 for every point of Experience earned by units or heroes in the empire. The second is Dust-Driven Distillery, an Era VI technology which increases the Dust production of all cities by 100%.

Quests
Much like ruins, quests grant rewards that can be an amount of Dust. However, the chance of this and the amount given varies depending on the specific quest, with some having no chance of granting a reward of Dust.

Urkans
Fakir has the Dust Leecher training available. Upon unlocking this training, while Fakir is rooted in a region, cities owned by Fakir's owner and their allies will get a +20% bonus, while enemy cities will get a -10%  penalty.

Upkeep
Upkeep is one of the main ways Dust is spent, as almost every city improvement, unit, and hero has a cost incurred every turn simply for owning them.

With the exception of most Era I city improvements and those that generate Dust, every city improvement has an associated upkeep cost, referred to as City Upkeep. This cost is usually consistent across improvements from a given Era - for example, most improvements from Era II have an upkeep of 2 - but this may change if the building is unique or cheap to build.

A unit's upkeep each turn is 1 extra per level. If the unit is in an army, then its upkeep increases an additional 1. Each army also costs to maintain equal to the maximum number of slots for the army, so an army with 1 level 1 unit that has a maximum of 4 slots costs 5  per turn. This makes a few larger armies much more efficient to maintain than many small ones. The combined upkeep cost for units and armies is referred to in-game as Military Upkeep. As an additional note, the Necrophages' Battle Born unit is able to exceed an army's normal maximum size if added to it via the Proliferator or, during a Dust Eclipse, Recycled Stockpiles, but this also adds greatly to the army's total upkeep, equation TBD.

Hero upkeep is much more complicated, as it is based not only on the hero's level, but also upon the number of skill points spent on that hero, and the number of other heroes you have. Exact equation for this cost TBD.

Additionally, for the Cultists or any custom faction with the "Conversion" trait, converted villages have an upkeep of 10 + 2  per additional city you control (This is only relevant for custom factions).

If expenditure exceeds the amount produced and the following turn will bring your total  into the negatives, you will receive the following prompt:

"Your Empire is about to go bankrupt. Your empire's expenditures are greater than your remaining treasury. If you do not adjust your Dust output, action will be taken and City Improvements, Units or even Heroes will be sold."

The prompt can be ignored, causing the game to automatically move all population to dust, sell/disband army units, dismiss heroes, and remove city improvements that require a upkeep until you are net positive on  production again. Each time it sells off objects, it will provide an itemized list of what was sold off. The game will not sell off city centers or settlers.

Upkeep Reduction
While one of the best ways to keep up with upkeep costs is to simply produce more Dust through the methods earlier in the article, another way is to reduce the cost of upkeep itself, which can be particularly effective with very large empires that have a lot of units, improvements, and heroes simultaneously. Note that while it is possible to have total upkeep reduction for some things in excess of 100%, this will only result in an upkeep of 0, not in Dust being produced by objects that once consumed it.
 * Reliquary of Auriga: Once built, reduces military upkeep by 50%.
 * Empire Plan: Tier 3 of the Military Ministry reduces military upkeep by 50%.
 * Cannon Fodder: This Necrophage technology reduces military upkeep by 50% and Hero upkeep by 20%.
 * Master Deceivers: This Forgotten technology reduces Forgotten hero upkeep by 100% (only applies to Forgotten heroes, not heroes from other factions that are owned by a Forgotten empire).
 * Infiltration: Heroes that are infiltrated on a city have reduced upkeep due to the Spying capacity, ranging from 40% to 80% upkeep reduction based on the level of the capacity the hero has.
 * Hero Skills
 * Thrifty: A common skill that reduces military upkeep for the army a hero is leading by 20% per level of the skill, has 2 levels.
 * Living Walls: A Wild Walkers skill that reduces city upkeep for the city a hero is the governor of by 30% per level of the skill, has 3 levels.
 * Ascetic Warriors: A Sisters Of Mercy skill that reduces military upkeep in the city a hero is the governor of by 50% per level of the skill, has 2 levels.

Buyout
Productions can be bought out (i.e. completed in 1 turn with the remaining cost being paid for) for. The cost for doing so is equal to (remaining cost)1.2.

This amount can be reduced by 25% for buildings and units via the Prisoners, Slaves, and Volunteers technology, and another 25% for buildings by Tier 2 of the Economy and Population Empire Plan.

Retrofit
Units within their own territory can be retrofitted to their most recent version. In addition to any strategic resources needed to retrofit a given unit, the Dust cost is (0.75 * cost)1.1.