Lore of Rain World

This page contains the lore and backstory of Rain World. Sufficient evidence has been found to support a logical explanation of the sequence of events that led to the current state of the world and its implications.

This lore may not be perfect. The following explanation is supported by evidence from texts and excerpts found in the game, but if more evidence should arise or a better explanation is provided, the lore is subject to change.

You are welcome to add or alter content of this page, but I ask of you to discuss it first in the page talk to ensure your evidence is valid and an agreement is reached. Once this page is updated, a list of evidences for the explanations below will be given.

Evidences regarding Moon's translation of pearls.

The events that transpired from the start to the end of the Rain World universe is complicated and entangled. The Slugcat's journey across the world is also riddled with clues and subtle messages of the past. Far more than just finding a home and a return to its family, its adventure is also a search for truth.

A number of evidences and excerpts acquired over the course of the game's storyline offer a logical and supported explanation in regards to the cause of the realm's current state of decay and disrepair.

The Ancient Civilization & Void Fluid
Eons ago, an ancient civilization inhabited the planet. Intelligent and capable, they ruled supreme over the realm. However, even such a developed society could not escape the grasp of the Great Cycle that impacted all living creatures. Birth, death and rebirth were connected to each other like a ring, and try as they might, none could truly die. Death would simply result in a new awakening—a restart, a repeat. Stuck within a deathless loop of agonizing longevity, it had long been this civilization's goal to break free of this cycle—a process known as transcendence.

Even far before the storyline of Rain World began, methods and spiritual instructions were devised by beings such as monks to rid oneself of their natural urges. They were practiced in an effort to escape the Great Cycle. However, there was no indication that these instructions were able to output any success.

The situation changed drastically, however, with the Void Fluid Revolution. At some point in their history, the ancient civilization discovered what later came to be known as Void Sea far below the surface in the Depths. The Void Sea was comprised entirely of Void Fluid. While it was difficult to harvest the fluid due to its nature of dissolving anything that comes into contact, devices known as Void Drills were invented to gather up small amounts Void Fluid embedded in rocks slightly above the Void Sea, where its concentration is lower and wouldn't pose a risk to the equipment. The impurities such as rock and sediments were then filtered out to obtain a sample of the pure liquid.

Soon after this, the fluid was found to be an outstanding source of energy. Armed with the potential of the Void Fluid, technological advancement boomed, and the ancient civilisation reached the height of its power.

After further studies, it was found that the Void Fluid does not just dissolve objects, it also removes them from the physical realm. Attempts were made to dig even deeper into the Depths to find higher concentrations of Void Fluid as well as uncover more information about it, but the ancients' equipment simply broke or dissolved. As later described, no one returned if they venture too deep into the Depths. However, this property of the Void Fluid coincided with what the ancients thought to be the solution to escaping the Great Cycle. The civilization believed that the ability of the Void Fluid to remove one from the physical world was the transcendence they had longed for. As whoever came in contact did not return, it was inferred that they must have broken free of the cycle. However, a risk was associated with taking the plunge into Void Sea to escape the world. Not even Void Fluid was enough to remove those with sufficiently large egos from the physical realm. This resulted in some "horror stories" in regards to semi-transcended abominations. Several ancients that did not entirely transcend are likely to be the six "blue-golden, glowing, squid-like creatures" scattered in the world. These creatures claim to know how to transcend, but express a sense of regret and sorrow at being trapped between the mortal realm and the transcended realm. The names of the six ancients are: It would seem that, in order to transcend, one would have to abandon all attachments and desires, entering an "effortless" state. The ancients once again turned to archaic methods to rid of one's natural urges and ego before deciding to use Void Fluid in order to avoid failure in transcendence. However, this seemed not to be an entirely perfect solution, which would explain why iterators were constructed (see below).
 * Nineteen Spades, Endless Reflection
 * Six Grains Of Gravel, Mountains Abound
 * Four Needles Under Plentiful Leaves
 * A Bell, Eighteen Amber Beads
 * Two Sprouts, Twelve Brackets
 * Droplets Upon Five Large Droplets

Creating & Using The Iterators
It was around this time that the height of the civilization's power had passed and they fell into an age of decline. The cause for this decay has not yet been revealed. Believing there to be an alternative method to transcend without the risks associated with Void Fluid, the ancient civilization used their technological prowess to create and construct the iterators. Iterators were the name given to supercomputers or artificial intelligence that were constructed to solve the “Great Problem”—to find the method of breaking free of the Great Cycle. Each was of a colossal size and held incredible power, and it was their purpose to think of and uncover a method to transcend without the use of Void Fluid.

Seven iterators have been named, but it is highly likely more were constructed. The seven are:
 * Five Pebbles
 * Big Sis Moon
 * Sliver Of Straw
 * Seven Red Suns
 * Chasing Wind
 * Unparalleled Innocence
 * No Significant Harassment

The iterators were a combination of organic and synthetic components, relying on specially grown microorganisms as peripheral processing devices: their natural metabolism and reproduction could perform very complex calculations beyond the capabilities of electronics physically. In order to cool their electronic components and keep their organic processing faculties in order, the operation of iterators required absolutely gargantuan amount of water each had to consume. The iterators stripped their nearby ecosystems of water and pumped water vapor back into the atmosphere, where it would condense into rain and be used again. Due to this process and the sheer number of iterators built, the equilibrium of the world's ecosystems was severely disrupted or even destroyed, creating a dense layer of fog and clouds rife with torrential downpours and periodic flooding. Ultimately, this effect came to be known as the Rain. The ancient civilization compensated for this by moving away from living on the surface, and constructed immense, dense cities directly on top of the surface of the iterators' "cans"—massive, square shaped buildings which protruded like islands far above the cloud layer. In addition to computing the solution to the Great Problem of transcendence, the iterators were tasked with providing regular shipments of food, water, equipment and Void Fluid for energy to these colonies.

Fall Of The Ancients & Pebbles' Madness
Unfortunately, the ancient civilization disappeared and collapsed before the iterators computed the solution to the Great Problem due to an as-of-yet unknown reason, possibly because the iterators could no longer satisfy the needs of the populace, or a massive transcendence movement of the entire population, leaving the surface cities dark and abandoned if largely intact. However, the iterators were left turned on, their final command being to continue working towards a method to transcend without using Void Fluid and guide lesser creatures on the path to the realm beyond should the solution ever be discovered. Over the next indeterminate amount of cycles up until the start of the game, the iterators did not achieve any major breakthroughs. Only Sliver Of Straw claimed to have uncovered the solution, but she "died" almost simultaneously as the confirmation of success was broadcasted to the other iterators, causing the methods in which she attained this positive result to be lost.

Unable to find the solution after Sliver Of Straw's death and growing increasingly frustrated, another iterator—Five Pebbles—ultimately had its thought processes compromised due to an infection or mutation of its organic components. Attempting to purge corruption from his system, he began drawing several times the usual amount of water. Unfortunately, by this point many of these components were capable of movement and rudimentary intelligence of their own, and so the systems flush proved to be ineffective in stopping the threat. The massive amounts of vapor emitted by the computer caused Moreover, the flushing of his system dumped a large amount of mutated organic matter onto the surface below, which formed the Garbage Wastes region and supposedly caused the surviving animal species to mutate into harmful lifeforms. In his desperation, Five Pebbles continued to draw water in order to accelerate his work on the solution and delay the infection's spread, causing him to tap into the water supply of another nearby Iterator, Big Sis Moon. Attempts by Moon to persuade Pebbles that water shortages would be fatal to her failed and she had to leverage her seniority in an attempt to make him stop, to which Pebbles responded that this plea has "ruined everything". To this day, Pebbles keeps consuming four times the normal amount of water, causing the rains in the vicinity of his facility to reach disastrous frequency and intensity. The damage caused to Big Sis Moon by droughts proved to be inconsequential compared to subsequent flooding: it caused Moon's memory banks to be destroyed, her facility compromised, and her primary cognitive unit to descend into a amnesic, near-death state. The fate of the other four iterators—Seven Red Suns, Chasing Wind, Unparalleled Innocence and No Significant Harassment—is unknown.

As violent as The Rain is, an ecosystem has developed under the bullet-like droplets. It is in this decaying and crumbling world of mysteries the Slugcat's adventure commences.

The Timeline of Hunter, Survivor, and Monk (Update spoilers)
It starts with the Hunter. NSH sends him (possibly created him specifically for this mission) with a green neuron and message in a pearl to Moon, because he realizes the vapor emission usually present on the horizon is not there anymore and wants to see if she's ok/help her.

Canonically, as we can see in Survivor which takes place a while after, Hunter delivers the neuron and revives Moon without eating any neurons. It is indeterminable if Hunter visited Pebbles at any point or if Hunter ascends or succumbs to his sickness.

Next is Survivor. As we all know he gets lost in a storm and is found by one of Moon's Overseers. The Overseer tricks Survivor toward Moon with promises of his family, in hope that Survivor will bring additional neurons to give her some needed support.

Canonically, Survivor does not bring any neurons to Moon and proceeds to visit Five Pebbles, achieve the Mark, and presumably ascend. We know this because in Monk, who takes place not too long after, Five Pebbles makes mention towards another Slugcat entering his chamber as well.

Finally is Monk. Despite jumping after Survivor in a vain attempt to rescue his sibling, Monk seems to take place noticeably a while after Survivor. The nature of Monks canon is unknown, because there is no possible way to determine whether or not he visited Moon, delivered her more neurons or ate them, visited Pebbles or got the final karma level through Echoes or if he ascended at all. Likely, due to the good nature and karmic relation Monk has, he ascended via Echoes and either didn't eat any neurons or gave her more out of sheer kindness.