Cerulean Seas is a third-party campaign setting for the Pathfinder role-playing game, released by Alluria Publishing in 2010, notable for being set in a world almost entirely submerged under the waves.
There was a bygone age when great expanses of land called continents existed, and they were ruled by strange creatures known as drylanders. They had a great age of peace where a magnificent city in the clouds kept evil at bay. One dark day, the Cloud City fell from the sky, and in their despair and ignorance the drylanders initiated a Great Flood that drove them to extinction and sunk most of the continents, leaving a few islands intact.
The world after the Great Flood is one ruled by the beast-tailed merfolk, the animalistic anthropomorphs, and the magical feykith. The eponymous region, the Cerulean Seas, were a great bay before Cloud City crashed into it and the Great Flood turned it from a bay to a shallow region of the vast world-ocean. While this is assumed to be the primary area of play, later sourcebooks also detailed the frozen polar seas of Isinblare, the darkest trenches of the deep sea, and the Far East equivalent region called Celadon Shores.
This game provides examples of:
- Absent Aliens: Inverted, there are a lot of non-human races but no humans.
- Benevolent Precursors: The drylanders' empire was a peaceful one that fought against evil.
- The Casino: Fortunis, the unofficial gambling capital of the Cerulean Seas, is home to many casinos, wastrels and sleazy types.
- City on the Water: Rumours describe Tel-Am-Karu, the ancestral homeland of the sebek-ka, as a gigantic artificial island chain that floats over a fathomless sea. Selkie cities also float, because they're carved into icebergs.
- Cool Gate: Travel in Isinblare is often done through hexagonal crystal mirrors that allow instantaneous transportation between Feldorheim and Fiskheim.
- A Crack in the Ice: Represented by thin ice, which will break under sufficient weight.
- Darker and Edgier: Both settings released in the supplements Indigo Ice (the polar seas) and Azure Abyss (the deep sea) are more hostile, dangerous and bleak than the default one in the core rulebook.
- Doorstop Baby: The morkoth are an entire race of this, as being in close proximity to their own kind causes them intense psychic discomfort. They mate only fleetingly, when biological imperative leaves them no choice, and females abandon their offspring to be taken in by foster parents. Even siblings will be left with different species and as far from one another as possible by their mothers.
- Far East: The Celadon Shores region is a blend of East Asian traditions and folklore, mostly Japanese, with a lesser dose of Chinese, Korean and Malay-Indonesian concepts.
- The Federation: The Dark Trinity, an alliance of three Underdeep races: the aquatic obitu, the deep drow and the oculi. In spite of being the epitome of Evil, their capital is probably the safest place in the deep sea thanks to their power, and they tend to be tolerant of other races as long as they are useful.
- Flooded Future World: An unknown event caused a global flood that covered most of the world in water and swallowed the cities of the drylanders, leaving the game's current setting dominated by scattered islands and vast seas.
- From Cataclysm to Myth: Ages after the great flood drowned the world under the waves, the tales about drylanders have faded into legend.
- The Great Flood: An event that happened a few centuries before the setting, which covered most of the world in water and swallowed the cities of the drylanders.
- Grim Up North: Feldorheim, the harsh, hostile seas surrounding the North Pole.
- Hiding Behind the Language Barrier: Carchardians and ixarcs often use their Pelagic language, which cannot be understood or spoken by other races, for secret communication.
- Indo-European Alien Language: The Halbok language is explicitly described to resemble Arabic.
- Mega Maelstrom: The biggest whirlpools can reach 2000 feet in diameter.
- Mordor:
- Hypoxic zones, areas of the sea with a particular lack of dissolved oxygen. Some of them are permanent, where travellers are advised to stay the hell away from and which have a distinct lack of natural life. Undead often plague these regions, as they do not need to breathe.
- Areas affected by red tide, which is toxic and kills most wildlife that encounters it, causing a massive rotting stench. Red tide can last days, weeks, or even become an annual or permanent hazard.
- The Nose Knows: Sharks can detect one drop of blood in twenty-five gallons of water and can sense even tiny amounts of blood in the water up to three miles away. Many other sea creatures have similar talents. Since underwater combat almost always yields copious amounts of blood, this can serve as a beacon for predators and scavengers.
- Outlaw Town: Wreckage is a pirate city, a bastion for thieves and cutthroats. When you need an assassin, black market goods, or even just cheap stolen goods, Wreckage is the place to go.
- Poisonous Person: The Cerulean Seas are filled with toxic denizens: puffer fish, lionfish, jellyfish, sea snakes and so on.
- Precursors: The great civilisation of the drylanders and their sahuagin enemies, which flourished before the great flood. The phantom lobsters are also described as descendants of a once great eurypterid empire.
- Prongs of Poseidon: Tridents replace swords, which are not very aquadynamic, as the most common melee weapon in this underwater setting.
- Psychic Powers: There's a whole supplement (Waves of Thought) which focuses on psionic powers.
- Public Domain Character: Among the gods, you might recognise some familiar names like Poseidon, Sebek, Aegir and Dagon.
- The Savage South: Fiskheim, which surrounds the South Pole, is no less dangerous than its mirror in the north.
- Single-Biome Planet: The campaign world is set on a planet which is 99% covered in oceans. That being said, the underwater environment is anything but homogenous.
- Starfish Language: Some can only be spoken and understood by select species due to limitations of either body or vocal range.
- Clickclack, the language of the karkanaks, is comprised entirely of click sounds.
- Cetaceans speak Ceti, a language whose range of tones extends into the subsonic and ultrasonic range, which cannot be heard by other races.
- Squid speak Cephalite, which uses multiple limbs, rapid skin flushes, colour patterns and posturing. Photok, the native language of the asteraks, is similar to Cephalite except that it uses a series of flashing lights.
- Sharks and rays' Pelagic language is based on scent and pheromones. Only pisceans and scream dragons are capable of learning it.
- The Medusian language of trueform jellyfish consists primarily of flashing bioluminescence.
- Suspiciously Similar Substitute: The game doesn't even try to hide that some races and monsters are just underwater versions of existing Pathfinder ones.
- Underwater City: Any civilisation worth their salt (pun intended) in an underwater environment should have a few of these.
- Underwater Ruins: Ruins of drylander cities are still scattered around the sea bed for intrepid spelunkers to explore.
- Vice City: The city of Kraken Bay is known as a haven for pirates and thieves, not a place for those without streetwise and experience with the seedier parts of the sea.
- Water Is Air: The game tries to defy this trope as much as possible, with meticulous detail given to mechanics involving underwater combat and how it'd be different from fighting on land. It's not just a campaign where 'everyone can fly' and all fighting takes place in 3 dimensions.
- You Are Number 6: Aglooliks, inventive feykith from the polar regions, incorporate numbers into their names along with a familial suffix.
