Nessus

Nessus stretches as a vast, wind-scoured plain, its surface jagged and split by chasms so deep their bottoms have never been seen. The storms here are fiery tempests, winds that carry burning ash and molten rain, scouring the land bare. The ground is blackened glass and scorched stone, interrupted only by the monumental trenches and canyons that shape the realm.   Nessus itself is the Pit, a planet-sized shaft ringed by terraces, hanging citadels, and spiraling bridge-roads that sink into the dark. Each terrace ring is miles thick and carved with its own cities, forges, and archives, complete with local codices of bylaws and tariffs. Etched into the wall itself coils a colossal spiral fault known as the Serpent’s Coil, said to be either the scar of a primordial serpent or the line upon which Asmodeus first inscribed law. No sky hangs above, only shifting pressure fronts that fall like curtains, smothering sound or heat with mechanical regularity, while avalanches of slag-ice and iron dust descend without warning.    

Notable Locations

Malsheem

The largest city in the entire Outer Planes, a sprawling, perfectly ordered metropolis built at the bottom of an unfathomable trench beneath the Pit of Cania. It is the heart of Nessus, a place where legions of devils lie in reserve, prepared for a war whose time has not yet come. From its center rises Fortress Nessus, Ashmedai’s citadel, a black monolith that pierces the skies above the rift.   Within its walls are found the Grand Chancery, the Red Basilica where capital trials are decided, the Abatement Forges where broken oaths are smelted into manacles, and the Audience of One, a hall that only Asmodeus himself enters willingly. Elsewhere lies the Iron Ledger, a vault-ring where contracts are etched into living iron that keens softly when clauses are breached, and the Silent Docks, where gravity-cranes and chain-elevators freight entire armies between terraces while unauthorized cargo simply vanishes. In the Mirror of Indictments, a lake of black glass reflects not the face but the crime one is most likely to commit under pressure. The Replevin serves as both courthouse and prison, a place where petitioners attempt impossible appeals, and those rare few who succeed become instruments of infernal law.    

Tabjari

A citadel of burnished copper standing along the jagged cliffs of Reaper’s Canyon. It houses one of the three surviving copies of the Pact Primeval, the foundational covenant of Hell. The other two copies are held in Mechanus and Heaven, and the presence of one in Nessus ensures that Ashmedai can never be denied the legitimacy of his rule.  

The River Styx

The River Styx winds through a hidden, heavily fortified tributary in Nessus before spilling into the Forgotten Lake, a shallow, oily basin that marks the end of its surface journey. From there, its waters sink beneath the earth, reemerging deep in Gehenna.  

The River Lethe

The River Lethe also crosses Nessus, vanishing and reappearing in the realm’s chasms. Its waters strip away memory and identity alike, and are often used in punishments or in the reshaping of a petitioner’s soul.  

Inhabitants

The plane teems with devils, from phistophilus attorneys to hamatula and osyluth wardens, erinyes prosecutors, cornugon generals, and pit fiend prefects. They are aided by kyton consultors who record and refine pain as data, by inevitables bound to procedural enforcement, and by soul-driven constructs that grind eternity into labor. Mortals appear as well—advocates, diplomats, and the supremely confident or supremely doomed—each one hoping to alter fate with an edit, or perish in the attempt.   Nessus is the domain of greater devils, amnizus, cornugons, and above all, pit fiends, whose sheer numbers here are unmatched anywhere else in the Hells. These forces are kept in reserve, trained and disciplined for an apocalyptic conflict known only to Ashmedai.   Every devil in Nessus is bound by layers of oaths, geases, and infernal contracts, ensuring absolute obedience. Even among Hell’s own, few are permitted entry without invitation.  

Government

Asmodeus is overlord, author, and final arbiter of all that transpires in Hell. He is polite, patient, unstoppable, ruling by paper more than blade, though none doubt his mastery of both. His government, the Chancery of Hell, is administered by phistophilus contract devils who audit every pact, erinyes magistrates who prosecute violations, and pit fiend legates who enforce policy without hesitation. His standing edict is simple: mercy is waste, efficiency and clarity are virtues, and loopholes exist as trials, never as mistakes.  

Access and Travel

Do not accept free advice, for it always carries weight. And never walk through a door that opens before you knock, for such doors know who you are, and why you have come.

  Movement across and beyond the layer is bound by Nessian Censorship: teleportation, plane shift, and similar effects collapse outright unless tied to an approved sigil-route, a writ of passage, or a destination the traveler is legally permitted to enter.   To survive in Nessus, one must come prepared: sealed writs, a notary or an impeccable bluff, climbing rigs and safeguards against falls, contingency measures that bypass censored teleport, and a contract ready for witnessing. Safe travel follows the numbered bridge-roads; stray ledges are often jurisdictional traps. Above all, never sign where the exits are unseen or the witnesses uncertain. Never bring open flame into a court, for it marks panic.  

From Cania

The Devil’s Steps, a labyrinth of vertical shafts and switchbacks, descend into the Ninth, patrolled by gelugon prefects who check writs and cargo.  

Astral Access

Rare and strictly controlled. Astral “ink-doors” open only when sponsored by an archdevil or the Mephistariate.  

The Styx

Does not reach the Ninth; all traffic is overland, through sanctioned portals, or ferried by infernal elevators anchored in the pit’s walls.

Nessus is Lawful Evil in its purest and most overwhelming form, a plane where lawful effects sharpen to cutting clarity and chaotic forces falter into impotence. The realm exists in a lightless void, broken only by engineered glows that seem less natural than decreed, with pressure, gravity, and even distance themselves feeling imposed rather than inherent. Here, authority is not won by steel alone but by edit and writ, for reality itself yields when a word is witnessed, sealed, and made cruel.   In this place the pact always prevails. Even truth bends beneath the plane’s weight; in courts and consecrated chambers mundane lies feel heavy and unconvincing, while insight sharpens, though magical deceit still functions, it leaves cracks thin as frost that devils exploit without mercy.   Nessus itself enforces contract and clause. Clausestorms sweep through in visible squalls of drifting glyphs, during which any spoken promise risks binding the speaker as if by lesser geas. At times, a faint ruby filament called the Redline threads through the air, sketching the course of events the contract desires; resisting its pull skews the world itself against you, footing, fortune, and circumstance alike, until payment balances the scales. When a pact breaks outright, the plane answers with Default, as the nearest metal surface erupts in razor-edged text that lashes the defaulter until restitution begins.