Sure, I've drilled-down the aesthetics of Cha'alt, the tropes that make the campaign setting what it is, thanks to my latest (free PDF) product Cha'alt X-Cards, but what about general knowledge about the world for noobs?

I was inspired by a Twitter post of this Hyperborea Primer, basically a bullet-point outline of what the native PCs would already know about where they lived.

This is one of those simple, useful RPG things that most people (including myself) just don't do.  I'm now kicking myself for having neglected it.  So, without further ado...

Cha'alt Primer

All player-characters who've lived on Cha'alt for at least several months will have general knowledge about the world they inhabit.  Consider the following general knowledge.

• The word Cha'alt means triumph by way of suffering; the kind of victory that is only achieved after long periods of struggle and hardship.
• Cha'alt's terrain is predominantly radioactive, inhospitable desert dotted with many small, tribal settlements and a few major cities, the largest of which is A'agrybah, closely followed by Kra'adumek... city of the purple, alien, demon-worm (both located in the northern hemisphere).
• Currency in urban areas is predominantly the talon, a triangular metallic coin.  Three talons equal one gold piece, which is the standard currency outside of cities (the Dome City uses colorful plastic shapes).
• The sky is fuchsia, turning deep-purple at midnight.  Cha'alt has twin suns and seven lavender moons, each having its own lunar cycle and are said to influence the destiny of men.
• The most valuable substance on Cha'alt is a viscous, glowing, chartreuse ichor known as zoth, and is the actual blood of Great Old Ones who've died - many perishing in the apocalypse that occurred 80+ years ago.
• The humanoid culture of today has been built upon millennia of demon civilizations that existed before humanoids "evolved" from primitive creatures, raised by tentacles of the Great Old Ones.  Self-interest, for example, is not just a commonplace notion or "necessary evil," but something to take pride in or celebrate, just as Cha'alt natives take pleasure in the cruel treatment of those different than themselves.
• Zoth is the ultimate substance, a super-science liqueur of transcendence.  It fuels magic, heals the sick, those afflicted with curses, and supernatural alterations.  It is raw, primal energy.  When refined, zoth is key to travel amongst the stars by folding space and granting access to the multiverse.  It's a religious sacrament, allowing brief communication with one or more Gods.  Drinking it is both an aphrodisiac for women and "power potion" for men.
• Crystals can be found all over subterranean tunnels and caves of Cha'alt, as well as, inside dimension-hopping pylons.  They are said to have collected the soul-energy of departed Old Ones, giving them spiritual properties.  However, the Federation uses these crystals to power their starships and high-tech weaponry.
• The Federation have repeatedly tried to colonize Cha'alt, but the natives have always proved resistant, forcing the Federation out when too many off-worlders try to steal the planet's natural resources.
• Even though Cha'alt has never been fully colonized, due to weakness, greed, and moral corruption, shadow politicians have instituted enough Federation-backed puppet regimes in order to change societal norms, culture, and living conditions.  Various aspects of the Federation cannot be questioned or criticized.  Mandatory vaccines allegedly preventing the outbreak of extraterrestrial contagions are disseminated quarterly.  On certain days, water is rationed, people are forbidden from worshiping the Old Ones, trafficking with demons, gambling, eating meat, or imbibing worm-wine and other hallucinogenic drugs.  In their place, State-sanctioned orgies of unrestrained sexual freedom and drugs specifically engineered for their effects of apathy on Cha'altian nervous systems (such as Fuchsia malaise) have pacified the masses.  
• A plurality of humanoids worship the Great Old Ones (Yog-Soggoth being the most prominent), though each God has his own unique vision for Cha'alt, if and when he should awaken.  But nearly as many people worship the New Gods, eschewing the ancient ways of infernal individualism and familial bloodlines for collectivist revolution subservient to The State who prefer alien culture (lots of weird sex stuff) and technology over sorcery and esotericism. 
• A lot of strange things happen on Cha'alt, which has led to various paradigms attempting to describe reality on this particular world - what is reality and how does it functions?  Leaving many to speculate that perhaps Cha'alt isn't real at all but some kind of holographic super-simulation or dream within the collective imagination of a Demon-God pantheon?
• The city of Qada'ath, known as the tangerine veil under fuchsia sky, is a rising metropolis built upon the secret of organic, arcane flesh-technology or flesh-tech known only to the civil authority of Qada'ath.  The tangerine veil is currently the fastest-growing city in Cha'alt's southern hemisphere.

Thanks for reading and sharing.  If you'd like to comment, I value your feedback.

VS

p.s. Attend VENGER CON III: Revenge of the OSR this July in Madison, WI.  Details about the basest RPG convention and grabbing your weekend badge is here.  Want your own Cha'alt trilogy in luxurious hardcover?  There you go.