Some of this may be outdated
Politics
What’s the common view of the Council? Popular, indifferent, hated?
Extremely popular. The strict regimenting and laws put forth by the Luminara Council are precisely why Lysandralis has lasted this long, and why the sense of community is strong. They allow the city guard to operate independently, giving them freedom to command themselves and honor their oath without the sense of blind loyalty.
Is the Council of Elders the government of Lysandralis, Elyssara, or both?
They govern Lysandralis alone, though some of their teachings and doctrines reach far beyond Lysandralis.
Are there other countries/city-states that don’t consider themselves subject to Lysandralis? Parts of the Underdark-analogue where drow/duergar live?
Glimmerholme and Thalindor have always been independent from other sovereign nations, epecially Lysandralis, as they believe that heavy restrictions on ingenuity and research can often cause nations to fall behind others. Though this is true, they often provide unique services to others that can only be found within their sovereign borders.
Trade
What trade relationships exist in Elyssara?
Many, both large and small. The most notable - and possibly important - trade relationship is between Lysandralis and Thalindor. The scholars of Thalindor have been studying the Long Dark for decades, and are directly heading up Project Dawnbreak. Thus, Luminalith crystals are required, and Lysandralis holds the monopoly on Luminalith shards, so a cohesive bond was formed between the two nations to help address the problems on the horizon, despite some members of the Luminara Council not entirely agreeing with the approach of the project...
Does Lysandralis trade with most/all Elyssaran cities?
Most, but not all. Taluk'Shar is still considered by many civilizations to be underdeveloped and primitive, and its citizens not always friendly. Trading is minimal with them. Several Orc raider brigades have been known to frequent the trade routes along Eastern Elyssara to plunder goods from unsuspecting caravans, so interest has dwindled...however, there is speculation among adventurers that perhaps Taluk'Shar is a self-sufficient community that holds far more secrets than they let on.
Are there established safe trade routes between Lysandralis and other major cities?
Yes, between Lumenethril and Goldarbor, most notably. The Long Dark's presence along well-established trade routes with other cities has made it difficult to transport goods and valuables effectively, so communications and supplies are quite limited in certain areas of Elyssara.
History
How far back does recorded history go?
Approximately ~5000 or so years, back to the Age of Creation when the primal forces of light and shadow formed the material realms. Every landscape you see and interact with was created by the Luminar and the Umbral, and even the cosmos beyond it.
When was Lysandralis founded?
Directly after Caelia blessed the world of Elyssara with the Luminalith, ushering in the Age of Radiance. So, approximately ~2500 or so years ago.
How long has the current form of government existed?
The Luminara Council has been around since a few years after the dawn of the Age of Radiance. Each member is carefully chosen by the High Illuminarch and the Councilmember being replaced, and this has been the normal routine ever since Lysandralis was founded.
Could there have been more eclipses in ancient history that people don't recall?
There is no evidence to suggest this notion. Ever since the creation of written language, scholars have been recording history diligently, and if something as profound as an eclipse occurred during any moment in history, it would surely have been documented.
Is there a common world-creation myth popularized by either scholars or the religious?
None that are of note.
Culture
What are common pass times in Lysandralis/Elyssara?
One of the most distinctive traditions in Lysandralis is the pilgrimage from the gates of the city to the plateau where the Luminalith once resided. Many religious practitioners - especially the High Illuminarch
recommend the pilgrimage as a yearly event to help "renew" your faith and to remind yourself of the teachings of the Luminar.
Stargazing and celestial observation is extremely commonplace within the city, and there are many observation towers for citizens to go about their favorite passtime in peace.
During the daytime, citizens take to sunlit walks among the many parks and pathways. Caelia's rays beaming down onto the faces of grateful citizens often prove to be therapeutic and relaxing.
Shopping at the markets is a staple in Lysandralis, and to not peruse the variety of goods available to every citizen on a daily basis is almost criminal.
How common are other races in Lysandralis?
Tieflings? Very rare. ~0.3% of the population
Orcs/half-orcs? Extremely rare. ~0.01% of the population. It's hard to find Orcs/Half-Orcs outside Taluk'Shar, other than raiders.
Genasi? Rare. ~0.5% of the population, with Fire Genasi being the most common.
Djinn? Non-existent.
Dwarves? Uncommon. ~1.0% of the population. As Lysandralis is well-known for its Lightcrafts, Dwarven artificers come from Glimmerholme to study under the best Lightcraft Artisans.
Halflings? Common. ~3% of the population.
Race relations - are various races/diversity tolerated/welcomed/shunned? are particular races feared/hated/subject to stereotyping?
Lysandralis prides itself on promoting the idea of community and embracing your fellow neighbor as one of your own. Thus, there are laws against discrimination or hate crimes.
Language
Is Common near-universal in Elyssara? Do some of the stone-age cities not speak Common?
The Common Tongue is the universally-spoken language in Elyssara, though some scholars believe that the entire world once spoke the languages of the Luminar and the Umbral.
How widespread are other languages? Elvish, Gnomish, etc.
It's quite uncommon to find someone who doesn't know multiple languages, either through direct exposure or education. Undercommon, Sylvan, Abyssal, and other esoteric languages are far more rarely seen or heard.
Religion
Pelor
How did Pelorian (spelling?) worshippers respond to the first eclipse?
While some kept their faith strong, others lost it completely or went into crisis; they viewed the First Eclipse as an evil omen, and one that suggested that Pelor's might was not entirely absolute.
Has Pelor ever made any documented appearances/miracles in Elyssara?
Yes. Despite blessing Elyssara with the Luminalith, Pelor's most notable act of benevolence was when we came upon a farm with withering crops. He plucked a single ear of corn from the stalks, whispered to it, then placed it in the ground. It grew into an ever-producing cornstalk that provided sustenance to the entire area. This story has been passed down through Peloric teachings as a reminder that one person can change a life for the better - possibly one of the most notable virtues that the city of Lysandralis adopts.
Are there other known deities of shadow/twilight that might be in support of the eclipses?
Peloric teachings speak of the Goddess of the Moon, Selunia. Though she is Pelor's polar opposite, she and him share a single belief - that Balance must be maintained, and that day and night must share the world together. Selunia has no reason to be in direct support of the eclipses, but when they do occur, Clerics of Pelor often blame her.
is their worship banned along with the Shadow Sect?
It is not uncommon for Selunia to be worshipped alongside Pelor as a way of promoting harmony between the light and dark, but for the most part, it is those who willingly attempt to disrupt the balance between them that are banned, such as the Shadow Sect. Their purposes for doing what they do are unknown, but they are in direct contention with the harmonious way of living in Elyssara.
Are there other well-known gods commonly worshipped in well-known parts of Elyssara?
Perhaps the next most-worshipped deity in Elyssara is Corellon Larethian, the patron deity of the Elves and forests. Moradin is devoutly worshipped as the Artificer God of the Dwarves. A smattering of other gods are worshipped throughout the land.
Shadow Sect
What is commonly known about the Shadow Sect?
Do they have a symbol or way of identifying each other that's recognizable to commoners?
None that are known to the common folk, but of course, mercenaries and scholars often speak of such a notion. If there is a way for a member of the Shadow Sect to identify another, they are keeping it well-hidden.
Are their motives/goals known?
No, though magical practitioners throughout Elyssara seem to agree that the eclipse brought about a new power to the realm, and they firmly believe the Shadow Sect seeks to harness it in its entirety.
Are they believed to be wiped out, clinging to existence, still powerful despite being outlawed?
Though they have not been seen or heard of since their momentous First Eclipse, there are those who believe that the Long Dark is somehow tied to their existence. So long as it remains, people will never feel at ease.
Eclipses
First Eclipse
How many people died? Are we talking a 50% population wipeout?
I would approximate a 25-30% loss in population. Northern regions were engulfed in a blistering cold, crops died en masse, and livestock perished. Everyone's way of life was upended, and it was hard to bounce back.
How drastic was the effect on the ecosystem? Total cascading collapse of plants from lack of sunlight, leading to starvation of herbivores and carnivores in turn, leading to a vast extinction? Or too short-lived to have such drastic effects?
The First Eclipse had a devastating effect on the environment of Elyssara. As mentioned above, entire ecosystems were lost to the sudden change in environment. The First Eclipse lasted for only a single month, but it was long enough for the world's resources to become stagnant, and for entire landscapes to become devoid of life.
Is there any reason to believe the flora/fauna of Elyssara have evolved adaptations to eclipses that might evidence many more eclipses in the past? Changed behaviors/attributes of flora/fauna during the eclipse?
No, not at this moment. The flora and fauna of Elyssara are vast and diverse, but the Long Dark has not been around long enough to be able to study definitively whether or not the Long Dark affects the development of sentient creatures.
What is the most popular Pelorian explanation for the first eclipse?
It is widely believed among the Clerics of Pelor that the Eclipse was merely an extreme test of faith, and was meant to remind the denizens of Elyssara about the delicate and precarious balance between the forces of light and dark that drives the cosmos.
What is the most popular scholarly explanation for the first eclipse?
The most popular explanation for the First Eclipse involves the idea of the moon Selunia obscuring the sun Caelia through some cyclical celestial occurance, which - through some strange force of nature or magic - caused some type of immense pressure within the Luminalith, forcing it to shatter. Again, this is the -most popular- theory, but this remains a speculative subject.
Hypothetical second eclipse
What is the common opinion on the likely outcome of a second eclipse? Do people expect the world will end if it happens again?
Since the end of the First Eclipse, many thought the Shadow Sect had disappeared. The problem, however, is the mere presence of the Long Dark itself, which many believe might be the key to their return...or that it means they never left at all. As for the notion of the end of the world occurring should a second eclipse arrive, yes - many believe this to be the case. Project Dawnbreak is quickly becoming the last and largest hope that Elyssara has to stave off the full engulfment of the Long Dark.
How prepared does the average person feel the world is to survive a longer eclipse?
Marginally prepared, only because of technological advancements being made that can help citizens survive the Long Dark. Otherwise, there are technically two places in Elyssara that could potentially survive the Long Dark simply because of their locations: Glimmerholme and Nerevyn
Has the government(s) taken significant action to prepare?
Yes, several. As was mentioned previously, most of the world's resources and efforts are being poured into Project Dawnbreak which, if successful, will theoretically banish the Long Dark for good.
Are there any relationships/arrangements with Underdark-esque civilizations in the wake of the first eclipse about what could happen during a second?
None that is known, though this could change.
Geography
Elyssara
Does the world map represent the entire (known) planet? Are there other continents on this world?
Zym has said any other existing continents are covered in shadow, and are considered lost.
Yes (to a degree), and to this point, this also means that technically, sea travel is permissible through the Long Dark...but I would NOT recommend such a journey unless you are well-prepared.
Are there other known planets/moons in the solar system with life? (ex. Gith in the Forgotten Realms)
There is no evidence to suggest this notion.
Other Planes
Do celestials and demons/devils exist?
Yes, though they tend to ignore the machinations of those on the Material Plane.
Is there a Blood War analogue between demons/devils in this world?
Not particularly, as they tend to avoid the Material Plane unless they are in search of something specific.
Do celestials/demons/devils make appearances/intervene on Elyssara?
It has always depended on the situation unfolding on Elyssara, but yes, they can appear in Elyssara from time to time.
Do outer realm analogues exist/are they known about? Things like Illithids in Forgotten Realms?
The Outer Realms definitely exist, and they are accessible through various means, but the Sundering was enough of an example of the wrath of the Gods to prompt humanity to avoid the Outer Realms.
Technology
Lysandralis
What'st he level of tech here?
Presumably plent of iron smelting and widespread agriculture?
Yes, very much so.
Pre-paper/printing press?
No! The printed word is alive and well, and there's even a courier company in Lysandralis!
Pre-gunpowder?
No. Gunpowder exists, and is highly regulated in Elyssara. It is seen as a means to a purely destructive end, and it is illegal contraband (which doesn't necessarily stop anyone from trading it...)
Indoor plumbing?
Most civilizations have a sewer system underneath them, but not particularly advanced in the ways of bio-material disposal. (In tabletop games, it is also generally assumed that your characters find a way to relieve themselves regardless of circumstances, and therefor, is not roleplayed)
Germ theory?
It is generally accepted that pathogens exist, but there are far more worrisome things in the world of Elyssara than the common cold.
Electricity? (magic or otherwise)
To a degree. Rich or well-off individuals or families will often use a mix of magic and the old-fashioned; i.e. torches, braziers, candles, fireplaces, etc., either real flame or evocative
Magic
how common is magic? Practiced openly? Can most people study and learn magic?
Magic among Elyssara is extremely common, and depending on where you go, can be either minimally or heavily regulated, and can affect public usage.
How common are magical artifacts?
"Artifacts" - items that are ancient and powerful in nature - are quite rare, and often require extreme hardships to obtain. Magical artifacts that have been discovered usually are kept under lock and key by the Scholars within the Mage's Guild of Thalandor.
Luminilith
When did the Luminilith first appear?
At the beginning of the Age of Radiance, marking the age's origin date. This occurred approximately 2652 years ago (~2500 CY)
Do Luminilith fragments have any well-known magical properties? Why are they sought after, other than being rare?
Because the shards of the Luminalith are the only things in Elyssara that can pierce (not dispel) the Long Dark, they are highly sought after, and pose a serious risk to anyone who carries one outside of Lysandralis or any other area of regulation.
What are common people supposed to do if they come across a Luminilith fragment, given unauthorized possession is prohibited?
Generally, the person who finds a Luminalith shard is supposed to follow the laws and regulations of the sovereign nation in which they found it. (In all actuality, these laws do not differ greatly from nation to nation, but some areas use them for other purposes.) According to Lysandralis and the Luminara Council, however, they consider each piece of the Luminalith sacred and holy, and its usage is extremely well-regulated, as they are necessary for defense against the Long Dark and for research into possibly dispelling it entirely.