| 1 person marked this as a favorite. |
I have been obsessed with the Soot Sea (and the Forgetting Place by proxy) - mentioned in the Vault Gazetteer with other possible area of interests in the Vault of the Onyx Citadel. Such a unique premise with some truly skin-crawling visuals for anyone who accidentally falls in. I wrote up some basic rules for the Soot Sea and figured I’d share them here in case anyone else was interested:
The Soot Sea is a network of caverns and crevices along the east and northeast walls of the Vault of the Onyx Citadel. Instead of water, however, the sea is made up of innumerable petal-soft flakes of soot. Even something as small as a mouse or lizard is too dense to stand or float atop the Soot Sea, and nearly all such subjects instead instantly disappear beneath the surface, never to be seen again.
Floating and Submerging:
For something to rest safely on the surface of the Soot Sea, it would need to have the surface-area-to-weight ratio of a sheet of parchment, or better. This leaves very little that can safely “float” atop the soot. A select few things can break this rule in the Soot Sea - mainly the Bone Ship that guards the Forgetting Place, and the Cutting Smolder, a special sailing ship designed by the Xiomorns that built the Vault. The remains of similar ships can be found along the seafloor - a few rare sites are actually beached on islands within the sea. It is believed that the Bone Ship is made up of the spirits and remains of all creatures who have perished beneath the surface of the sea.
Not many creatures are native to the Soot Sea, let alone those who live beneath the surface. The most well-known exceptions are the Soot Sea Krakens, who have adapted to swim through the soot as well as they might in water. It’s unclear what agendas these bizarre creatures hold, for their intellects are roughly the same as those clever Krakens who dwell in Material Plane oceans.
For non-native creatures, being beneath the surface of the Soot Sea creates a number of hazards. First, traditional visibility is impossible. Scent-based perception is possible, but comes with its own perils (see below). The most reliable methods of visibility are Tremorsense, which functions fully, and Echolocation and other hearing-based perceptions function normally, but have their ranges halved.
Creatures who must breathe to survive must hold their breath beneath the surface or inhale dry soot. This includes creatures who breathe water or air, though creatures with the Earth subtype can breathe normally in the soot. Creatures who breathe in soot are Staggered for 1 round as they aspirate, and starting on their second consecutive round breathing in soot, also take 1d4 Con damage. A Fort save (DC 15 +1 per consecutive check) negates the Staggered Condition and halves the Con damage. Casting spells while under the surface of the Soot Sea requires the same Concentration check as doing so underwater. An Air Bubble spell benefits creatures who breathe air while under the surface, both for breathing, and for casting spells.
Finally, unless a creature wades into the sea at a gradual shore (though most banks are themselves drop offs, and it’s usually impossible to tell, anyway), a creature entering the soot is met with no resistance, and plummets at full speed until they hit the seafloor. The soot offers only the faintest resistance while falling and cushion upon landing, and falling creatures and objects ignore 10’ fallen for every 60’ fallen, but terminal velocity still reaches a crushing 20d6, eventually. The topography of the seafloor is a mystery to nearly anyone who sails it, but there are chance shallows, though there also exist perilous depths. Roll a d% when someone or something falls into the soot, and note the below chart (I didn’t include the chart here). Remember that in a freefall through the soot, a creature or object falls 500’ on the first round, and 1,500’ on the second round. If a creature reaches a depth of 1,200’ before landing, they’re treated as landing in water. If a creature reaches 1,800’ before landing, they take no damage. See below for more details on extreme depths.
The soot cannot be swam or burrowed through, nor can it be climbed. Walking can only be accomplished along the solid rock bottom, and where the seafloor becomes too steep to walk, it can be climbed (though if the climber doesn’t have a means to see, they take a -5 penalty on their checks). Mechanical flight is possible, though all maneuverabilities drop by two steps, and the creature must make a DC 20 Fly check at the start of each round to avoid dropping 1d% feet, and the DC’s of all normal Fly checks increase by 10. Magical flight is easier, but still difficult, dropping all maneuverabilities by one step, requiring the same Fly check to avoid falling each round (though only DC 15), and all normal Fly checks have their DC’s increased by 5 instead of 10. Whether magical or mechanical, all fly speeds are halved. The changes in topography means that creatures flying blind risk ramming into a solid wall from a drop off; taking damage, and risking a plummet. Spells that offer flight through gaseous forms function normally beneath the surface.
Spells like Air Walk and Sky Swim, that allow a creature to walk or swim through the air, do not function beneath the surface of the Soot Sea; it’s unclear why, though most magical scholars have theorized that such spells recognize the surrounding soot to be earth, and therefore fail to activate properly, just as if the subject were fully submerged in dirt, the spell wouldn’t effectively grant a burrow speed. Earthglide remains as the best method of travel, receiving no penalties or hindrances.
Though only a fraction of the density of water, the Soot Sea will slowly build up pressure if you travel deep enough into it, as the soot petals become finer as they are themselves crushed under the weight of their own brethren. At depths greater than 500’, movement is halved (or quartered for fly speeds). At depths greater than 1,200’, creatures begin taking 1d6 nonlethal damage every minute. At depths greater than 1,800’, movement is quartered (flight becomes impossible), and creatures take 1d6 lethal damage and 2d6 nonlethal damage every minute. At depths greater than 2,000’, burrow speeds can be utilized for navigation (at half speed), though without Earthglide, creatures are still subject to the crushing pressure.
Navigation:
The normal light ever-present in the Vault doesn’t fully reach into the crevices and caverns making up the Soot Sea, and so it is perpetually dim light, though some of the banks near crevice openings are still normal light. Though wind seems to flow in from the open Vault and through the walls of the Soot Sea with remarkable ease, the soot itself seems supernaturally resistant to being kicked up by this wind, and the wind rarely penetrates the soot surface. Occasionally, intense wind storms are strong enough to kick up soot and create pockets of soot storms. Creatures caught in these Soot Storms are treated as if they’re beneath the surface of the Soot Sea, though they must also contend with the high wind speeds as normal; the high wind speeds make it much easier to accidentally aspirate soot, which increases the save DC by 2 to avoid being Staggered and halving Con damage.
If a creature is fortunate enough to be aboard the Cutting Smolder, or managed to salvage and repair a destroyed ship, such a ship sails over the soot with the same speed and maneuverability as a sailing ship over water, though oars and other mechanical propulsions do not work, leaving wind power the only reliable form of locomotion. Profession (Sailor) checks can be made as normal for navigation, though creatures unfamiliar with the Soot Sea take a -4 penalty on these checks. Creatures capable of flight can do so over the surface of the Soot Sea without penalty or hindrance.
The Cutting Smolder
The Cutting Smolder is a Sailing Ship that’s been magically outfitted to be buoyant atop the Soot Sea. This ship is a relic from the Xiomorns who once managed the Vault of the Onyx Citadel. The Peches that now sail aboard it aren’t capable of constructing such a vessel or (with the exception of Carbonax) maintain it. The Pech Wizard has accrued just enough magical competence and know-how to keep the Cutting Smolder operating, though the ship is always possibly one major setback away from being unfixable.
The crew of the Cutting Smolder is made up of 12 Peches, total. Seven 3rd-level Unchained Rogues make up the main crew, and usually take lengths to avoid any of the grand dangers present around the Soot Sea. The ship’s officers are much more capable, and consist of three 10th-level Swashbucklers and the First mate is a 10th-level Ranger. Carbonax, a 14th-level Transmuter, as the oldest and most powerful Pech, not to mention the only one with even a rudimentary understanding of how the ship works, acts as the ship’s captain.
The Cutting Smolder facilitates a lucrative, if dangerous, operation that’s kept the crew well paid, so long as they work carefully. The ship has several enemies within the Soot Sea, mainly the Soot Sea Krakens who occasionally venture near the surface, and the Sinister Bone Ship that occasionally acts as a guardian of the Forgetting Place.
| 1 person marked this as a favorite. |
In my own Ironfang Invasion campaign, I altered the plot of Vault of the Onyx Citadel to send the party to all six geomantic nexuses (How can I remove slavery from Ironfang Invasion? comment #58). And to a seventh geomantic nexus I added, the Sand Nexus, nearby Stonehome. The module gave the whole 140-mile-wide map of the Vault, so I wanted to adventure across it rather than stick near the Onyx Citadel. Besides, I was altering the adventure path to reach 20th level.
Cuup could do the same: ask the party to visit all the geomantic nexuses and add a seventh nexus, the Soot Nexus, in the Soot Sea. The party could negotiate with the crew of the Cutting Smolder for passage across the sea to the nexus. That would be an interesting adventure.