For the sake of new readers (and at the suggestion of a reviewer), I’ve decided to put together a basic codex for in-universe terms/concepts. This list isn’t comprehensive and only covers basic explanations. I'll update it over time... If I remember to.

>Ikesia/Ikesians - Ikesia is a united nation formed from a group of independent city-states by an individual known as the Sage of Fog. The country was severely damaged by its defeat in the War of Fog, and while the nation still exists under heavy occupation, many of its constituent states have returned to operating independently.

Ikesia also refers to the geographical region. The country shares its eastern border with Grekuria and its western border with Pateiria. Its northern border is mostly next to a mountain range, neighboring several small mountain-bound kingdoms and city-states.

Ikesians are the primary ethnic group which has inhabited the area for longer than written history has been recorded. They are extremely pale-skinned (sometimes referred to as “Snowmen” or “Snow Demons”) and universally quite tall. Hair colours tend towards either platinum blonde or pitch black, with a minority of redheads.

Recessive Ankhezian genes manifest in Ikesians somewhat more commonly than in other ethnicities, which supports historical records that claim Ikesia was once a major population center for the Ankhezian Imperium. This is further corroborated by the fact that the Ikesian population at large exhibits the same extremely fine, nearly nonexistent body hair.

They are known to be somewhat insular and resentful of foreigners in positions of power, as modern Ikesian culture was born from rebellion against non-Ikesian feudal lords five centuries before the story takes place.

Under the Sage of Fog, Ikesia made leaps and bounds in scientific progress, going through a masterfully orchestrated industrial revolution in a couple years and forcing its way onto the world stage as an industrial powerhouse that made up for its small size with fire and steel.

This led to the War of Fog, which is covered further in this glossary.

>Grekuria/Grekurians

Grekuria is an old state which has gone through numerous periods of expansion and shrinkage throughout its long lifespan. The country’s borders are majority sea-adjacent, though their navy is in the stranglehold of merchant families, rendering them a relatively minor naval power in a military context.

Grekurians are a diverse people due to their country’s multicultural heritage. Grekurians are the ethnicity most commonly mixed with Ikesians, due to the historically blurry nature of their borders. Their skin colours run the gamut from relatively pale to bronze-brown. Their hair colours tend towards darker shades.

Grekuria is neither technologically advanced nor far behind, and they are not particularly militarized - they do not practice drafting, for example. Their government is extremely powerful, though it lacks any single figurehead as a relic of the country’s history - they technically have a High Chancellor, but the seat has remained empty since the last chancellor stepped down.

Their justice system is inquisitorial in nature, yet it has a relatively low conviction rate - they’ve maintained the trappings of theocracy while stripping away the teeth bit by bit. Those inconvenient to the merchant clans have a tendency to get suicided or be conveniently found with incriminating material, however.

>Pateiria/Pateirians

A truly sprawling empire whose sheer size vastly surpasses any other single country, rivaling the Ankhezian Imperium at its height. It is an autocracy led by the immortal and inhumanly powerful Divine Emperor.

It is heavily stratified by caste and clan, and separated into smaller regions which are autocratically ruled by their own local governors.

A large majority of Pateiria is made up of smaller settlements, inhabited by subsistence farmers who scarcely care for the rest of the world, pay their tributes to the Emperor in rice, and worship him in earnest as some far-off deity rather than a man in a palace. In these regions, he is often depicted as a white-gold dragon clutching a sword in his jaws, a rice stalk in one hand, and the sun in the other.

Pateiria remains one of the last bastions of widespread religion on the continent, with large-scale faith having died out in other countries and been replaced by smaller, local, oftentimes much older forms of spirituality.

Pateiria is highly collectivistic in nature, reducing individuals to little more than cogs in a machine, valuing them for what they can do to benefit the collective. In the same way, Pateirian culture punishes transgressions not because they are considered wrong, but because they harm the collective.

If a man murders another, and the context of the murder results in the act benefiting the collective, the man will not be punished.

This manifests in Pateirian merchants being considered so extremely untrustworthy that even the Kargarians refuse to trade with them unless they have the Pateirians at gunpoint.

>Kargaria/Kargarians

Kargaria is less of a specific country and more of a term used for the far-off lands from which the Kargarian caravans hail.

They are a nomadic steppe culture that naturally slid into the role of caravan traders and quickly became a tremendous force financially, technologically, and culturally, due to their constant travel. They have never had official borders or territory, and possess means of travel that surpass all others - they are the only group known to practice long-distance “Fog Sailing”, a mysterious mode of travel known to permit one to traverse thousands of miles in a fraction of the usual travel time and unimpeded by physical obstacles.

Kargarians are also one of the most significant naval powers in the known world, and most major pirates are known to be (officially) renegade Kargarians. Of course, the goods which these “renegades” plunder tend to show up as caravan cargo rather quickly.

They are a culture which greatly values individual independence and martial skill due to their lifestyle, placing heavy emphasis on swordsmanship and speed. The achievement which any Kargarian swordsman seeks is to split a lightning-bolt and in doing so claim the power of lightning for themselves. All of this reflects the pressures that their home places upon them, being plagued by absolutely lethal fauna and violently stormy weather.

Kargarians are ethnically diverse and commonly multilingual, and have played a major role as cultural cross pollinators throughout all of known history. Even ancient Ankhezian records mention them as the “Merchants of Menace”.

>Ankhezia/Ankhezians/Elves/Imperials - An ancient, long-lived, isolationist civilization. They ruled most of the known world at some point, but their empire has declined to the brink of destruction since. This was due to an attempt at uniting the at-the-time fractured empire by bestowing immortality to their people, which, while successful, also resulted in widespread infertility, reducing birth rates to a fraction of normal.

This only exacerbated existing tensions and caused a civil war that wiped out much of their population.

As well as immortality, this misguided project caused some less notable changes that were meant to make the Ankhezians seem to be inherently beyond human.. Ankhezians and Ankhezian descendants are known to possess certain entirely cosmetic traits, including an altered composition of sweat that renders it inedible to the bacteria which produce body odor (thus eliminating body odor), as well as extremely fine body hair (in males) or nearly nonexistent body hair (in females).

Their legacy survives mostly through genetics, as those descended from them exhibit prolonged lifespans and elongated ears.

>The Sage of Fog - An enigmatic figure who appeared seemingly out of nowhere and united Ikesia over the course of a few years. He was known for his aversion to violence, his genial intellect, and his possession of nigh-prophetic knowledge.

Much of Ikesia’s advanced technology was initially drafted based on concepts that the Sage claimed to “simply know”. He had a strange fixation on gift baskets and was rumored to be able to travel anywhere in Ikesia at will.

He disappeared on the same day that the Blackwall appeared.

The Sage is described by a character in one of the early chapters of this book, so I do not find it necessary to cover him any further.

>The War of Fog - The first instance of industrialized warfare and a near-apocalyptic event that significantly damaged civilization as a whole.

It was a defensive war. On one side stood Ikesia, several independent city-states, and Kargarian mercenaries. On the other was the overwhelming might of the Pateirian Divine Empire and the Grekurian Statehood, both major world powers.

The conflict was largely initiated by Pateiria in concert with Grekurian merchant clans, drawing Grekuria as a country into the war through old treaties.

In the end, Ikesia dragged both its opponents into the muck of trench warfare and ground them down in the cogs of its war machines. What was meant to be a short war to punish an upstart newcomer, became a merciless meat grinder that left all participants nearly crippled.

At the end of it, an unknown event in the south-eastern regions of Ikesia caused the formation of the desolate Exclusion Zone, which is expanded on later in this document.

One of the main cast summarized the context behind the war early in the previous book:

“We all know it was a matter of face for the old powers. Think about it. A couple city-states suddenly get united by some jackoff that calls himself the Sage of Fog. Not only do they make giant leaps in manufacturing technology enabling them to mass-produce things that take your craftsmen tens of man hours to produce, but they categorically refuse to share this technology and force you into trade deals that, while good on paper, are extortionate when you take manufacturing costs into mind.”

“The old powers needed to put us in our place for the sake of face. So they send a couple Fog-breather led battalions, maybe some golems or what have you, shave a couple kilometers off our borders and take a factory or two.”

“Next thing they know, they’re getting pounded into the dirt with rolling thunder artillery and an army of peasants is fighting and winning against their trained martial artists using mundane blades and glorified muskets. No wonder they pulled out all the stops, to them it must’ve been like Ikesia climbed onto the table of international affairs and pissed on it to claim it as territory.”

“And I’d wager they’re more than willing to kick us while we’re down if we start rebuilding a little too quickly. Maybe incite some extremism to justify further occupation, who knows. Not much stopping them with the Sage dead.”

>Arts - Everything from magic to special weapon techniques. They’re effectively spiritual muscle memory, allowing someone to consistently reproduce a difficult feat as long as they have already done it once by burning the necessary essentia within their body for fuel.

They were made common by the use of assistant devices, most commonly tablet-shaped attribute-readers.

>Attribute Readers - Magic PDAs, basically. There are more common, cabinet-sized versions that are often in public spaces - think of Fallout’s Vit-o-Matic vigor tester. These being used are some of the only cases when blue boxes show up.

>Essentia - Alchemic elements, the arcane building blocks of everything. The world of Retribution Engine is dual - the mundane together with the arcane. Essentia is often used as fuel for machines/techniques.

There are ten “Primordial” essentia, the most fundamental of the fundamental, and a functionally unlimited number of composites. The Primordial essentia are broken up into two groups - those of the living world, and those of the unliving world.

Albedo, Nigredo, Rubedo, Viriditas, Azoth - The first four of this group are inherent to all life in some aspect.

Albedo is the untouchable essentia, also referred to as the essence of the soul. Has not been explained in-story and is poorly understood. Pretty much the only concretely known things about it is that it exists and that it is often contained in the last exhalations of the dying.

Nigredo is the essence of decay, it is black in its pure form. Found in corpses, rotting things, burnt things, organic waste.

Rubedo is the essence of survival, of violence, of instinct. In larger amounts it drives one superhuman strength in fight-or-flight states, it numbs pain, somewhat analogous to adrenaline. In much smaller amounts it stimulates other instincts, in humans this effect is most commonly aphrodisiac in nature.

Rubedo is often found in places where violent death has occurred on a large scale recently, taking the form of pools of blood-like liquid.

Viriditas is greenness, the pure essence of life and greenery, it is the most commonly occurring essentia in living things. Most life is made up of a significant fraction of this, with plants containing a far larger fraction - some species of algae are nine parts out of ten Viriditas.

Viriditas-based solutions are highly effective and very common as basic restorative elixirs.

For example, Fulgur comes about from two parts Ignis, one part Aqua, and one part Aer, and so on.

Azoth refers to two things - gemstones that naturally occur within the bodies of certain living things, and the mercury-like liquid at the cores of those gemstones. In effect, an Azoth Stone is analogous to a magical core, containing the essence of the owner. They can be absorbed wholesale (inflicting severe side effects unless you REALLY know what you’re doing) or they can be specially processed through a variety of alchemical methods to isolate the parts of the Azoth that you want.

At a point in the preceding book, it was discovered that the formation of an Azoth Stone within the body is effectively the first big step in self-cultivation. It is also the only step that most cultivators ever take, due to the fact that the Divine Emperor of Pateiria has spent the last five centuries spreading misinformation in order to stifle the growth of potential threats.

Aer, Aqua, Ignis, Terra, Aether - The essentia of Air, Water, Fire, and Earth, plus Aether. I don’t think these each need a specific explanation, they act as you might expect. It should perhaps be noted that they are heavily used as power sources - many houses have running water fueled by an Aqua gem, motorized vehicles run on Ignis-based fuel cells, etc.

Aether is the “Primordial Fog” that gives the Sea of Fog its name. It can be considered a sort of primordial energy, or an analogue for Qi/Chi/Mana.

>Fog/Fog-breathing - Fog-breathing covers a wide range of breathing methods which enable one to take in Aether from the Sea of Fog - the most common use of this is enhancement of one’s physical capabilities and the numbing of pain sensations. Fog is a colloquial term used to refer to the visible exhalations of Fog-breathers - it can be considered magical exhaust. The substance is a gaseous pseudo-matter that quickly fades back into the Sea of Fog.

>Homunculus - Engineered organic life. Extremely wide term, most commonly refers to alchemically grown/modified body parts.

Another common application is alchemists creating homunculi of themselves in the form of little men in jars with adult faces that act as fleshy records of the alchemist’s knowledge at the time the homunculus was created. In this way, an alchemist can partially immortalize themselves.

These types of homunculi are known to be incapable of ever improving in any way, be that growth or learning - they only ever degenerate, as they deplete the artificial amniotic fluid in their containment vessel whenever they do anything.

>Souls - Every living thing has a soul. The souls of trees are known to be adjacent to human souls in size and brightness. Inanimate objects are known to develop souls, the first widespread application of this knowledge being the Ikesian Captain’s Cleaver. Beyond this, souls are not very well understood by contemporary science in-setting.

>Captain’s Cleaver - One of the only mass-produced weapons made from cold-iron. The Ikesian military issued them to squad captains, and the weapons changed their shapes to best fit the user.

A Captain’s Cleaver requires a relatively high Force and Aether rating to use effectively - without sufficient Force, it’ll be dead weight. Without sufficient Aether, it won’t obey you. If the user meets both requirements, the cleaver’s tremendous weight will be significantly mitigated by the weapon’s ability to dynamically shift its own center of mass.

>Cold-Iron - A term as wide as “steel”. It covers most forms of iron-based, arcane metal.

Cold-iron is generally superior to its mundane counterparts, functions as a magical conductor and possesses shape-shifting capabilities, though the extent of these properties varies widely.

Items made from Cold-Iron tend to develop their own souls far more readily than other items.

>The Exclusion Zone

A field of self-perpetuating decay only kept at bay by a long daisy-chain of runestones that convert the E.Z.’s Nigredo into Viriditas, imbuing the forests surrounding the zone with unnatural growth.

The only thing concretely known about it is that the E.Z. was first created around the same time as the Blackwall was raised.

>The Blackwall

An incomprehensibly massive wall surrounding most of Ikesia. Its raising is thought to have been the Sage’s last desperate act.

The Wall cannot be traversed by any means, including means of travel that would otherwise allow one to ignore physical obstacles. The only way to traverse the wall is to pass through one of its many gates, which only open to some people, choosing seemingly arbitrarily.

Generally, the wall won’t allow anyone openly hostile to Ikesia to pass.

This, unfortunately, means that many desperate Pateirian and Grekurian veterans are now stuck in Ikesia and forced to turn to banditry or terrorism.

>Lightgems - Gems that glow. Usually pieces of quartz are specially treated in some way to facilitate the storage and burning of essentia to produce light. Most commonly this is done through a simple ritual wherein a large quantity of gems are placed in a basic ritual circle and allowed to sit out during a full moon, creating the most basic form of lightgem.

They store and burn a mixture of Ignis and Aer to produce light. The former is recharged by exposing them to fire, the latter is just absorbed naturally even while the gem is glowing, pretty much reproducing the function of a candle.

Lightgems have functionally replaced other, fouling light sources.