It is a plane without charity, mercy, or pity. It is the Oven of Perdition, the Fourfold Furnaces. It is where yugoloths cavort on endless volcanic slopes. Gehenna's top layer borders Hades and the Nine Hells, so it is not a pleasant place. Floating in an impenetrable, infinite void are volcanic mountains seemingly without base or peak. They are only finite in the strictest sense of the word, measuring hundreds of thousands of miles in each direction. A single volcanic mountain dominates each of the four layers of Gehenna, though lesser volcanic earthbergs drift and sometimes smash into the greater mountains.
There is no naturally occurring level place in any of the layers; all the slopes are at least 45 degrees, and many are akin to sheer cliffs. Gehenna's fiendish inhabitants have carved artificial ledges, some large enough for entire cities, and switchback paths to connect them. But those edifices not carved by native yugoloths or deities have a tendency to break apart, sending their builders on a long, sliding fall down the mountain. Gehenna's four layers are Khalas, Chamada, Mungoth, and Krangath. Each layer is differentiated from the other by its degree of volcanic activity. Powerful entities that possess realms on Gehenna include many lords of the yugoloths, as well as Melif the Lich-Lord and Memnor, deity of evil cloud giants. The realm of Maanzicorian, an illithid deity, was once located here. But Maanzicorian was slain by Tenebrous, the name taken by the demon lord Orcus when he first returned from supposed annihilation. Accordingly, Maanzicorian's realm has started to crumble, its deity gone.
Gehenna has the following traits.
Normal Gravity: Gravity is similar to the Material Plane, but naturally occurring volcanic mountains seem to float free in an infinitely larger void. Gravity is normal on the steep slopes of a mountain, and a fall tumbles victims many miles until a chance ledge catches them, or continued rolling abrasions of the fall completely shred the victim.
Normal Time.
Infinite Size: The impenetrable void of Gehenna is infinite, but each volcanic mountain is finite. Each is far larger than the largest known land mass on the Material Plane, however.
Divinely Morphic: Memnor and other deities can alter Gehenna's mountainous landscape. Ordinary creatures find Gehenna is as alterable as the Material Plane.
No Elemental or Energy Traits.
Mildly Evil-Aligned: Good characters on Gehenna suffer a –2 penalty on all Charisma-based checks.
Normal Magic.
Like all the lower planes, Gehenna has the River Styx flowing through at least its first layer, Khalas. In fact, it is the biggest river on the layer, and it hurtles through gorges and canyons with breathtaking speed. Its cataracts are legendary, and the occasional ledge creates waterfalls of epic, if polluted, proportion. Attempting to change planes via the Styx is a very dangerous thing indeed, on Gehenna. Portals to other planes are fairly common, as are portals between layers of Gehenna. They usually appear as bottomless black chasms. Sometimes they are marked as portals, but sometimes yugoloths mark actual bottomless chasms as portals by mistake or with malice.
The yugoloths, masters of schemes, are most at home on Gehenna, though sages note that yugoloths actually originate in Hades. But the yugoloths have been on Gehenna longer than most of the deities who now have their realms there.
Petitioners of Gehenna are the refuse of the planes. Greedy and grasping, they care only for themselves. Expect no favors from such a petitioner unless proof of immediate recompense is at hand. Unlike on many of the other Outer Planes, petitioners on Gehenna are more willful, traveling from layer to layer on their own personal quests for power. They're looking for the ultimate exercise in free will, though they are destined to never find it. Gehenna's petitioners have the following special petitioner qualities: Additional Immunities: Poison, acid. Resistances: Fire 20, cold 20. Other Special Qualities: Surefooted. Surefooted (Ex): All petitioners have a +10 competence bonus on Climb checks.
Movement on Gehenna is much like movement on the Material Plane, though the mountainous, sloping nature of Gehenna imposes constant dangers.
Because every natural surface on Gehenna slopes at least 45 degrees (except for occasional ledges and artificial constructions), moving from place to place is dangerous. The description of the Climb skill in Chapter 4 of the Player's Handbook describes how characters move about on Gehenna's slopes. The DC for Climb checks on Gehenna varies from 0 for ordinary slopes to 15 for steep areas and 25 for sheer cliffs. Creatures can move at one-quarter speed as a moveequivalent action on the sloping surfaces, or at one-half speed as a full-round action. Attempting to move faster incurs a –5 penalty on the climb check, as described in the Player's Handbook. Those who fail their Climb checks make no progress. If they fail their Climb checks by 5 or more, they fall. If a fall occurs, the victim rolls, bounces, and rebounds off the endless steep slope of Gehenna. Falling characters get a chance to catch themselves by making a Climb check (DC 10 on a slope, 35 in a steep area, and 45 on a cliff). If the fall occurs in a random location, the victim comes to a stop on a natural ledge some 10d10+100 feel farther below and takes 10d6 points of damage from the bouncing, bone-jarring descent. In some locations on Gehenna, a victim's fall could end sooner—in a river of lava.
Combat on Gehenna is much like it is between two climbing foes on the Material Plane. Anyone on the surface of Gehenna's mountains loses his Dexterity bonus to AC and cannot use a shield. Attackers get a +2 bonus to attack climbers, even if they're climbing themselves. A climber who takes damage must immediately make a new Climb check against the DC of the slope. If the climber fails, he immediately falls, taking damage as described in Falling on Gehenna, above.
Each layer of Gehenna (called a mount) is slightly different, but each burns with an evil will. The lava flows seem to seek out the casual traveler, and fissures open under a visitor's feet as if the ground itself hungers. As on Carceri, the sloping earth itself provides light, so shadows stretch upward.
The air of Gehenna's first and lowest layer has a crimson tint near the ground, due to the magma flows and pyroclastic ash, but it quickly fades to black no more than a few dozen feet overhead. Strangely, the next mount, Chamada, is visible in the darkness overhead, though it is so far away that it burns like a small, bloody moon. The slopes of Khalas are streaked with waterfalls and cloaked in steam. The falls
never find the bottom of the layer, either evaporating or disappearing into fissures. The mightiest waterfalls are those made by the River Styx as it makes its tumultuous passage across this forbidding layer.
Teardrop Palace: Located along the Styx, a nautilusshaped pagoda crouches with two smaller shrines set beside it. A wrought-iron fence encircles Teardrop Palace, which occupies an obviously deity-carved ledge. The pagoda measures miles on each side, as do the lesser shrines. A crowded bazaar thrives between the two smaller shrines, filled with milling yugoloths, petitioners, devils. demons, other outsiders, and the occasional mortal visitor. The bazaar buys and sells everything the ultimate black market because almost everything has been stolen from some other part of the Great Wheel. Prices are high and pickpockets are a constant threat, but the market has a reputation for selling exotic, hard-to-find items.
The second mount of Gehenna is the most savage. The slopes burn with constantly flowing magma so thick that solid, cool ground is rare, and so bright that the glare blots out the sky itself. Cascading lava rivers sometimes harden and briefly dam the fiery flow, only to explosively burst forth in new directions. Vents unexpectedly open, spewing fresh ejecta, and miniature volcanoes are common. The air itself is usually filled with feather-soft gray ash, which falls everywhere like dread snow, often dropping visibility to zero.
The Crawling City: A great metropolis of obsidian and ash, the Crawling City moves across Gehenna, moving from layer to layer at the will of the its master, the general of Gehenna. The Crawling City moves by virtue of thousands of fiendish, fire-immune legs grafted under the massive lower deck of the city, allowing the metropolis to cling to the steepest cliff face on Gehenna and slowly ford the broadest river of lava. The general is an ultroloth whose power is said to approach that of a demideity. In theory, all yugoloths answer to the general, although the yugoloths' proclivity for plots and webs of deception means that many have divided loyalties.
The city has low barracks for devilish, demonic, and other assorted elite mercenaries, and siege towers housing potent war magic. There's also a war academy where brilliant fiendish strategists teach their lore to up-and-coming officers bound for the Blood War, and massive factories where smithies constantly turn out the latest in fiendish military hardware. The Crawling City itself, in all the millennia of its existence, has never directly entered the Blood War. Ancient prophecies tell that should it ever do so, the Blood War will finally reach a decisive conclusion in an apocalyptic final battle.
Nimicri: From the slopes of Chamada, Nimicri appears as a small moon about 2,000 feet in diameter. It floats in splendid isolation above the burning mount, covered with spires, steeples, and less dramatic structures connected by a weblike network of streets. Everything is clean, the buildings are comfortable and in excellent repair, and every citizen of Nimicri is quite polite. Excellent goods of all sons can be had at the trading post, and Nimicri is an established stop along several trading routes that crisscross the Outer Planes. What most visitors never realize is that Nimicri— buildings, people, and all—is one vast creature that mimics a town. Sometimes Nimicri absorbs a visitor into itself completely, but other times it allows visitors to leave completely unharmed. If even a single drop of a visitor's blood spills onto any surface in the city, Nimicri is able to duplicate that visitor exactly, including memories up to the point when the blood was spilled. If a “citizen” of Nimicri is ever forcibly removed from the town, it immediately dies like a limb severed from a body.
Tower Arcane: This tower rises high above the lava flows and ash clouds of Chamada, decorated with blades and spikes that promise pain and death to unwelcome visitors. Yugoloth wizards control the tower, which functions as the record vault for the yugoloth race. The history of the yugoloths can be found here, though the information is well protected and heavily encrypted with glyphs of warding, symbols, and other protective spells. The interior halls of the Tower Arcane support the bodies of flayed petitioners dangling from chains. The wizards use the blood of these petitioners (and the occasional unwelcome visitor) to pen their history. Torture paraphernalia line any walls not given over to bookshelves and sealed archives. Deep below the tower lies a vast library of particularly ghastly contracts with mortals, extending for miles. The most potent protective spells in the wizards' arsenal protect the sanctity of the library from encroachment by molten rock or extraplanar thieves. Each contract is inscribed on the living skin of a petitioner, burned in with magic and branding irons. Petitioners are strung on chains like popcorn on a string for miles in parallel lines of agony. The only thing on the mind of any given petitioner is its own particular contract and its personal pain.
The third mount is far less volcanically active than either Chamada or Khalas. In fact, it is quite cold and often covered by snowfalls. The light of scattered volcanic vents is akin to the light cast by a full moon, making navigation across Mungoth's icy slopes difficult. Even that light is sometimes snuffed out by a heavy snow and ash fall. The combined snow and acidic ash are dangerous to travelers without shelter. The ice that accumulates on Mungoth's slopes gives a –4 circumstance penalty on Climb checks.
Valley of the Outcast: A deep chasm contains a wellhidden realm sheltered from the ever-present acidic snow. Built of equal pans basaltic rock and giant bones is a rough castle. The castle is scaled to the proportions of its master, an outcast fire giant wizard named Tastuo. Her eight siblings, fellow outcasts, also reside in the castle. Like their sister, all are either wizards or sorcerers. Yugoloths of the layer have several interlocking contracts with Tastuo, which helps ensure the valley's safety should her enemies ever find her. Tastuo never names those enemies, but her predicament makes her sympathetic to the plight of travelers seeking asylum. Thus, the Valley of the Outcast doubles as a way station for visitors in need, but only if they can find it.
The snow-ash mixture on Mungoth deals 1d4 points of acid damage per minute of exposure. Only artificial structures or caverns offer any lasting protection against the snowfall, which blows through any given area 80% of the time.
The fourth mount of Gehenna, the Dead Furnace, is devoid of volcanic activity; it went inactive millennia ago. The great mountain of the layer is a darkened pillar rumbling in the night. The layer is shrouded in silence. No wind stirs and no light glimmers. Krangath is dead. Petitioners are rare, and those that move about on this layer have learned to keep quiet, lest Melif hear them.
Hopelorn: An artificially maintained ledge holds a precisely fashioned complex of obsidian. Dim, reddish lights are visible in tiny, slitlike windows throughout the complex. This is Hopelorn, the stronghold of Melif the Lich-Lord. Hopelorn is a mortuary city where sarcophagi glow like streetlights and necromantic energies dance wisplike over every boulevard. Here undead are welcome, but not so the living or petitioners, whom Melif regards as pathetic losers unable to properly manage the passage of their mortal lives. In Hopelorn, Melif and a cabal of liches and other powerful undead spellcasters conduct their undying research into the nature of life, death, and being. Sometimes Melif and his assembly capture fiends for outrageous experiments, though they are careful never to capture yugoloths, lest the wrath of that race fall squarely on Hopelorn. Besides, it is rumored that Melif was once a yugoloth himself, before he steeped himself in the eldritch arts and eventually lichdom.
Use Table 7–7: Hellish Encounters for random encounters on Gehenna.