I'm currently programming an original slugcat into rain world, The Capacitor
I have several mechanics outlined, and also plan to add a custom campaign, eventually. It's a great project for me - the first programming project I've had the motivation to work on in my spare time, and helps me practice! Under the cut are more details on the characters lore, planned abilities, and campaign, if you're interested. Feel free to message me about anything at all regarding them, or rain world in general! This post will be updated regularly as concepts are decided on.
Rain world and Downpour spoilers, obviously.
Lore:
The concept is called The Capacitor, a slugcat directly descended from a lineage of purposed slugcats that could generate and release charge to jump start equipment and stuff, and the idea is that while they have evolved a bit, they still have that deep, programmed urge to fulfill what they were built for
Issue is they appear around / after saint in the timeline so most of the iterators are... collapsed or generally nonfunctional
So the idea is that they go on a long journey looking for greater purpose (a.k.a. an interator), and eventually find one called Roots within Glass, a lone iterator that is the last standing structure in her local group (likely implemented through some kind of rail-travel or something to a far-off region in game or something, idk) RWG sees this psudo-purposed bio-electrical creaturr and has an idea:
Her structure is on the verge of collapsing, so she instructs the capacitor to do its job- power up her systems to restore function to her for a big last process- since the collapse of her structure is imminent, she reasons that she can squeeze a questionable process past her no-self-destruction taboo; porting her neccisary memory and function from her puppet to a biomechanical part in The Capacitor, if it can prove itself capable of keeping them both alive
So after the capacitor restores power to her structure, she gives it an honorary ancient-style name, then transfers herself into them, for a few key reasons.
the obvious, keeping herself functional
being integrated with a biological creature gives her more freedom around her restrictions, as she can just have them do things
in tandem with this, it provides her with a new option: ascencion via the void, as biological creatures work that way!
If she can successfully integrate herself, then that right there is a triple affirmative for her fellow iterators that are still standing! (Actually i might have used that term wrong, but the point is it lets iterators potentially ascend)
After this, the capacitor will require more food to keep the symbiosis of the two alive, and also is able to let RWG take control for brief periods, allowing them access to some of her godlike iterator powers
The end goal being to send out a triple affirmative (i think), then either ascend or help RWG move past her purpose and find joy in living.
Mechanics:
Food:
requires 8 food pips to hibernate, and can store an additional 2 pips between cycles. Food functions as it does with hunter; corpse food for full pips, as well as some meat (jellyfish, vulture grubs, all else is 1/4 efficiency. As their ability *can* drain their hunger, but doesnt neccisarily require it, i gave them a low carry-over. The specific numbers are meant to make multiple hunts a necessity- since most lizards are worth 6 pips, you would have to either scavenge a bit and hunt one, or hunt two of them- with the full carry-over food allowing you to only need one lizard to fill up.
Charge:
The Capacitor has a meter representing stored charge.
Pressing [whatever it's bound to] while the bar is filled to at least 25% will activate output mode, draining the meter slowly over time and granting a number of additional effects!
Charge is refilled in a few ways;
It is fully replenished at the beginning of a cycle
It refills very slowly over time while not in output mode - unless you are starving.
If you attempt to activate ouput mode with less than 25% charge, or leave it active as it reaches empty, you will spend one food pip to restore 50% (subject to change, might end up being 25-30%) of your charge. Theres is a bit of a grace period for the latter scenario, and a warning trill.
Keep in mind- if you try to refill your charge in either manner while you have no food, you will be kicked out of output mode (if you let it drain) and have have a seizure!
While in output mode, you gain the following effects:
General agility is increased. Running, jumping, crawling, and climbing, as well as movement tech such as backflips, are faster and higher. (Does NOT give you rivulet-level backflips) this is why the meter drains over time.
Jumping and throwing can be overcharged! By holding the output button breifly before doing either of these actions, the capacitor will charge up for a more powerful version, costing 25% of your overall charge meter. (If you have less than 25% remaining, it will simply cost the remaining meter and then kick you out of output mode.
Charged jumps will launch you omnidirectionally, and they can be chained multiple times in the air! Keep in mind, they take a moment to charge up, and if you run out of meter, you don't have a safety net. That means four jumps max, or five if you jump normally beforehand. Your meter will not be refilled from food pips while in the air!
Charged throws throw faster and further, dealing increased damage with spears, or increased knockback and stun with rubbish/rocks. This could also be used for more powerful item- boosting over large gaps! Keep in mind that because of the strength, spears will be more likely to stick in walls when thrown, and become unretreivable.
You gain the ability to discharge into creatures. It works similarly to a maul- while grabbing a stunned creature, you can spend ALL of your remaining charge to shock them- stunnung them similarly to an electric spear, and dealing damage in proportion or the amount of charge you have. At full charge, this damage would be ~2.5, but I still need to do some testing to see what feels fair. This is very much meant to be a last resort option, as doing so spends your resource for other actions that could be more useful. It's also risky when considering the next bullet point. Centipedes are also immune to this ability. (I might reduce this feature to exclusively the following bullet point, and replace it with a back spear. Not sure, just because... giving them a back spear just feels like it takes away from hunter for some reason.)
If the capacitor is bitten, they will discharge instinctively - dealing only half of the damage and stun a normal discharge would do. This ability also does NOT prevent the inital damage from a bite- a red lizard will still kill you 100% of the time. This automatic survival mechanism will still drain all of your remaining meter, with a few exceptions.
If the instinctual discharge is cause by being shocked by a centipede, your meter is instead fully replenished, and the centipede is killed outright! However, because of the explosive nature of this interaction (seriously, the centipede will blow up) it will leave you stunned for a generous amount of time, during which you will not be in output mode, and therefore defenseless. Additionally, shocks from red centipedes will still kill you, even if they do die in the process.
Empty electric spears will be recharged :)
Roots Within Glass:
These mechanics I'm still brainstorming. After RWG integrates herself into the capacitor, their required food increases from 8:2 to 10:3, for the reasoning that RWG requires a fair amount of power to keep running, even in her simplified state, but also allows for more over-storage to make use of your - and her - abilities.She can be awakened by [button input im still figuring out], which takes a few seconds, and then begins rapidly draining your meter- while your charge is draining in this manner, there is no buffer for food pip consumption- it will eat through them quickly if you arent careful. The actual abilities for this mode I havent decided on, although some strong contenders include dev-tools style throwing around a single creature, or the single-lazer blasts that Sliver of Straw uses in the early sections of challenge 70. Dunno!
Low quality concept art
Note: i dont plan on giving them a back spear, i just thought it looked cool
The Capacitor is now finished and released on the steam workshop! The campaign is still a work in progress, but the character himself is up and working!





















