Mermaids in this world are split into four kingdoms. The RiverGills, who live near the river, the DepthGills, who live in far below the other groups, the PolarGills, who are more separate from the other kingdoms and more technologically advanced, and the CoralGills, the stereotypical mermaids that live near the coast. Mermaids can speak English, more frequently spoken by CoralGills, but most speak a language called Reefian. Reefian has a small set of letters and dialect tones to accommodate for the difficulty of writing in stone. DepthGills have a language called Lumen Code. It's "spoken" by flashing their tail lights in different patterns, somewhat like morse code. It used to be a way for soldiers to send secret messages, but DepthGills use it as a fun way to communicate. All mermaids believe in the same gods. Tida, the sea god, made the 4 kingdom gods. Currum, the god of the RiverGills, Lumen, the god of the DepthGills, Cyron, the god of the PolarGills, and Reefia, the goddess of the CoralGills. Currum is said to have blue hair that flows like the river. He brought the river so that the sea could always flow with water. He represents the free spirit and adaptation. Lumen is said to have blue spots that glow like a jellyfish on his tail. He saw the depths of the water and noticed how barren it was, so he filled it up with strange creatures and DepthGills. He represents secrecy and mystery. Cyron is said to have fur around his arms. With his ice powers, found it unsuitable to live near the shore where the other kingdoms were. He decided to move far away from the others, going to the arctic and making his PolarGills there. He needed to find a way for the PolarGills to get to the other mermaids, so he gave them speed. He represents intelligence and craftsmanship. Reefia is said to have beautiful, long hair that shines with the colors of the rainbow. She thought that the ocean was lacking color, so she made coral and many different fish, making the first coral reef. She saw how beautiful humans were and based her CoralGills off them, inspiring the other kingdoms. She represents elegance and beauty. Every full moon, or the Watching Night, mermaids of all kingdoms gather in peace, as they believe this is when all the gods are watching. They make special food just for this night and dance. They offer gifts to their gods, like precious metals and food.