Gameplay

First off, let it be said: the gameplay of Rain World can be difficult, if not severely punishing. Most of the mechanics of the game are hidden to the player at the start, besides the basics of movement and survival. There are many nuances to gameplay that give the slugcat slight advantages against its lethal environment.

Rain
After enough time passes in each cycle, rain will begin to pour down, slowly increasing in strength, and eventually killing the player unless they find their way to a shelter. In its initial stages, the rain will only weigh you down slightly, making some jumps harder. After a short time, however, the torrential rain will become strong enough to push slugcat around and eventually kill the player. If the player hides underneath some ceiling, the rain will still eventually become lethal, but the player will buy a small amount of extra time to find shelter. Some rooms will not experience rain, but will instead flood with water as the rain arrives. As slugcat will eventually drown in water, these rooms will offer no safety. Only a shelter will let the player avoid the rain.

To determine the amount of time you have left until the rain arrives, hold the map button and look at the bottom left corner of the screen. There, around the symbol of karma, are tiny circles that are either filled or emptied. As time goes on, full circles will turn to empty circles, and then disappear. It takes 30 seconds for each circle to disappear. Once all the circles are empty, the rain will arrive.

Players should take care to avoid having to race against the rain when possible. Ideally, the player will reach a shelter with enough food to rest before the rain ever arrives.

Karma
Main Article Karma

Initially, there are five levels of karma, each with their own individual symbols. On the hibernation screen, there is a vertical dial of these five symbols. Depending on whether the Slugcat hibernated or died, the dial will either rise up or drop down in symbols. In order to go up the levels of karma, the little slugcat needs to gather enough Food (four or more) in order to hibernate at the shelters. Once in the chambers, the screen will change to the hibernation screen, where you'll be awarded with a cute picture of a sleeping slugcat and an increase of your karma level. As you get to the higher symbols, you'll be able to pass to different areas that were once inaccessible. Though be careful while traveling, as dying will result in lowering the dial to a lower level of karma (You can avoid this from happening by eating the Karma Flower at the location of your previous death). Outside of the hibernation and death screen, your karma level is displayed on the bottom left corner of the screen alongside the time and food counters.

When the rain begins, if you enter a shelter without eating enough food (at least 4 slots), the chamber will close and you'll go to sleep as usual but you'll die of starvation inside, thus the karma level will still drop anyway.

To reach certain areas of the game, you'll need to pass through the Gates. These gates have floating symbols over two large pits with a large gate separating the two pits. In order to pass through the Gates, you'll need a high enough level of karma as displayed within the circle. Anything above will allow passage, but anything below the needed symbol will result in the symbols turning red and the gates not opening.

Passage
Main Article Passage

"Passage" is a game mechanic that allows you to respawn at any previously-used shelter (even in different Regions). One passage use becomes available each time an in-game achievement is unlocked, making them a finite resource to be used sparingly. Progress of Achievements can be seen as the smaller symbols surrounding Slugcat's karma level.

Passage will also completely refill your karma meter. This can be useful for scenarios where you are stuck at a high level karma gate and don't have the food or patience to hibernate several times. But take note that passage will always send you to a specific shelter in any given region, so you may still have a bit of backtracking to do to get back to the karma gate after passing.

Pressing the "Passage" button during in-game hibernation allows for one to be used. If accidentally activated, the passage can be preserved if the game is exited before a shelter is selected.

Techniques
Main Article Controls
 * Jumps & Platforming
 * Backflipping can be achieved by running in a direction, then hitting the opposite direction and jumping at the same time. Backflips add a little height to your jump and are useful to back out of an open area quickly.
 * Wall-jumping is pressing the same, then opposite direction from a nearby wall while simultaneously hitting the jump button. It's required to easily access some locations in the game.
 * Sliding is done by going forward and holding down and jump at the same time. If you press jump halfway through a slide, you will leap and gain a good amount of distance. Slugcat can also slide under enemies as an escape.
 * If you're holding a diagonal direction off of a good amount of jump height, you'll roll a few times as long as the ground remains flat. If a jump is done during rolling, you'll leap instead of finishing the roll. This can also be chained off of a backflip.
 * You can clamber onto a ledge by holding up and forward. This makes hard jumps that usually require a stick to act as another platform easier, and if the jump button is pressed at the right time (or mashed enough for trial and error), can afford you double jump height against a wall. The latter tech requires amazing timing and may otherwise come out as a walljump, so use at your own risk.
 * Sticks and spears can be lodged into walls to be used as a ledge/pole/platform to climb up on. You must be relatively close (within a few slugcats lengths) for it to stick, otherwise it will definitely bounce off. Sometimes if you don't throw at a solid section of wall, such as the corner of a pipe, and not a it will still bounce off. Beware, you can lose spears inside pipes, though.
 * Pipes
 * Pipe-jumps give you a small boost of distance while crawling in a pipe, however, there is a brief slow-down at the end. Pipe-jumping while crawling upwards will slow you down more and cause you to lose a little distance during the recovery due to gravity, however pipe-jumping while crawling downwards will initiate a freefall and cause you to descend incredibly quickly.
 * Long pipe-jumps can be executed with a well-timed pipe-jump in certain circumstances which will give you extra distance. When first entering an area through a pipe, or when you turn a hard corner (there is wall behind slugcats feet), if you time a pipe-jump well, slugcat will spring off the wall or pipe opening and gain two to three times as much distance as he normally would, giving you a huge advantage, especially in chase scenarios.
 * Crawling in a pipe backwards is slower than crawling forwards. Press the jump button while moving backwards to turn around. This will take the slugcat a moment to reorient itself, but it's well worth it.
 * When entering a new room via pipe while being chased, you can run back into the same pipe before the enemy comes out without being in danger, they can't attack you while travelling between rooms. This will put distance between your pursuer. If this pipe juke takes you away from your destination, just wait for the enemy to chase you into that room and perform this a second time to bypass them again so that you can end up going in your original direction.
 * Water
 * Slugcat takes a powerful stroke underwater when the jump button is pressed, best used for quick dives or resurfacing.
 * Slugcat can hold his breath underwater for about 30 seconds, this period of time shortens as you press the jump button to move faster (so it is recommended that you don't press it if you're swimming long distances). Leeches and Snails are a few of the obstacles you may encounter in water. Snails stun the slugcat for a few seconds if you linger near them for too long (if you see them begin to shake, they are about to pop). Direct contact with them may result in them popping immediately. Snails can be grabbed without the worry of them popping in your hand, so it's a good strategy to grab them before they pop to prevent the stun. Leeches will swim after the slugcat and attempt to attach to them, slowing your swim speed. Be aware of how many there are in one place, as if too many latch onto you, the slugcat will begin to sink. Red leeches are weak, meaning it will take about 5 or 6 of them to drown the slugcat. The longer blue sea leeches are stronger, and it will take about 2 or 3 of them to drown the slugcat.
 * A technique called waterjumping exists: if you hit water at a high enough speed and press the jump button at the right time, you can jump off of the water as if it were a solid surface. Small-scale waterjumping is possible by spamming the jump button on the surface of the water, making you swim faster.
 * Food & Items
 * Slugcat is able to swallow inedible items to regurgitate for later use by holding the grab/eat button (once to swallow, again to regurgitate). Slugcat can only store one item at a time in this fashion. Some small creatures such as Hazers or Vulture Grubs, can also be stored in this way. Neuron flies, can be eaten if not full. If the slugcat is full, they can also be stored.
 * Slugcat is only able to hold one spear at a time, but can hold two of practically anything else. There is an exception with the Hunter(Red Slugcat) that is able to hold one spear on its back and have another equipped.
 * Slugcat will almost always use its right hand (left from the player's perspective) first for any given actions (throwing, eating, dropping, picking up, etc.) before using its left hand. You can swap items between slugcat's hands by double tapping the grab button.
 * Some creatures, like snails or vulture grubs, can be grabbed and thrown to disable or distract enemies.
 * Misc
 * Slugcat makes less noise when crawling on the ground and can sneak past creatures that rely on hearing.

Strategies

 * You can lure a chasing predator into a fight with another by running to it or by having it chase you as well. This works with different tribes of scavengers and all predators, regardless of species or subspecies.
 * As Slugcat is one of the faster creatures in the game, running is always an option. For creatures faster than you, aim to disable with a weapon before running away.
 * Most creatures will kill you immediately among contact with their mouths, but it is possible to escape if you can get out of a tentacle or tongue before immediate consumption. This also works with creatures that try to drag you before eating you, such as the Pole Plant.
 * Water can be useful for evading some predators, but others will be much harder to avoid while swimming.
 * Try not to provoke neutral creatures, as many will be beneficial to you when friendlier.
 * Try to stock up on food as much as possible, especially before resting at a shelter. Having a weapon for defense is great, but you usually can find something along the way, and avoiding fights is sometimes a safer bet. Building up karma is important too, especially if you are going to need to get through a gate soon. Whenever there is an abundance of food, fill up on creatures (i.e. Batflies) first, and then finish with plants (i.e. Blue Fruit) if necessary. Then grab two plant food sources and hold on to them, bringing them with you to the shelter. After resting, you have enough food to sleep again and immediately gain another karma, or you can go explore and in the case that you don't find more food before finding a shelter, you already have enough to sleep and save progress.
 * Don't be afraid to do "dry runs" of an area with no plans of surviving in order to learn the map, practice dealing with predators, and plan out a path for yourself. Heading into new regions is optional, but not recommended during these runs. If you die in this new region without managing to reach a shelter, your karma will drop, and (depending on how much karma it takes to get through that gate) you may not be able to go back through. However, you still fill out the map you have access to, so you can always discover new areas even if you die.