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You are a nuclear power plant operator working at the Rasvyat Nuclear Power Station. You and up to 5 other players operate the historic RBMK-1000 reactor, after learning how to operate it, you and your fellow operators must start up the reactor and keep it stable, along the way you may face various issues and have to preform various tasks.

Once started you must keep the reactor online for as long as possible, however various events can occur, including various system malfunctions, power outages, earthquakes and more.

Every action made by you and your fellow operators has an effect, even a discission made for convenience or something done an hour ago could eventually cause a problem, any mistake threatens the reactor, risking damage to equipment or even a reactor meltdown.

1.0.2a Changelog

This is a small update but I hope it makes the game a little better regardless, Merry Christmas and Happy New Year!

Completely new button SFX (From real RBMK equipment)
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Bug fixes
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Physics Tweaks
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[ 2025-12-29 10:37:53 CET ] [Original Post]

1.0.2 Released

1.0.2 Changelog

New Content

Added the ability to manually zoom in and out with the scroll wheel (along with still having a manual zoom with right mouse)
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Temporary Christmas main menu theme
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Various bug fixes
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Various physics tweaks
\n(For the full list, check the PTB patch notes)\n
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Important Notes

The AR system is still being worked on, and will be added in a small patch down the road
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In addition, the in game tutorial has been disabled and will not be re-enabled until said small patch, until then, new players can watch the official guide on my channel as it has a lot more detail than the in-game one
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[ 2025-12-25 09:08:16 CET ] [Original Post]

Rasvyat 1.0.2 Public Test Build is live

I haven\'t directly announced this on Steam until now (Only in the Discord previously), however I\'ve been running some test builds for the 1.0.2 update, and the first mass scale one is now live on the public-test-build branch.\n\nIt should be noted that this is not the complete 1.0.2, it is still missing some features (namely the automatic regulator system that\'s going to be added in this update), however it does still include several new optimisations, quality of life changes, graphical improvements and reworks to other things in game.\n\nWith all that being said, please make sure to report any bugs you find in the community Discord server in order to improve the full 1.0.2.

Wrenchy Productions

As apart of a publisher deal with Wrenchy Productions, Rasvyat is partnering with them. This will not impact the creative direction of the game whatsoever, and moreso exists as a way to establish a partnership for future games (in which they\'ll have more of a hand).\n\nI will likely be doing a larger announcement with more details when it comes to the full release of Rasvyat 1.0.2, the main reason I\'m doing this smaller announcement is to explain why it now mentions Wrenchy Productions on the startup screen.

\n1.0.2 (Public Test Build) Changelog

New Content

Added the ability to \"unlock\" the mouse using the \"F\" key
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Added new effects for when multiple channels rupture
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Added some new background SFX
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\"Additional AZ-5 Signal\" annunciator is now functional
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Gameplay Changes

AZS Rework

AZS default mode renamed to \"AZSP\" (to better distinguish the mode from the system)
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UZS default mode renamed to \"UZSP\" (to better distinguish the mode from the system)
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AZSP period limit decreased to 10 (was 30)
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AZSP accuracy is severely decreased over 110MWt
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AZSR accuracy is severely decreased under 95MWt
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The warning \"Reduction in UZSR\" annunciators now activate at a period of 60
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The emergency \"Reduction in UZSR\" annunciators now activate at a period of 40
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The warning \"Reduction in UZSP\" annunciators now activate at a period of 40
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The emergency \"Reduction in UZSP\" annunciators now activate at a period of 20
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UZSP will send a malfunction signal if active over 150 MWt
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UZSR will send a malfunction signal if active under 90 MWt
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If you go 10MWt outside of these limits (EG: over 160 MWt in UZSP mode or under 80 MWt in UZSR mode) an automatic AZ-5 signal will be sent\n
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KOM Rework

KOMs speed has been significantly increased until being reaching 3.5 meters (at which point it will move slightly below the usual speed)
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KOM no longer drops the AR rods
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KOM now completely locks all control rod movement for 10 seconds after being canceled
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KOM now has an annunciator
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KOM no longer selects control rods (the selsins still light up while in motion)
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AZM Rework

The \"AZMM\" annunciator has been retired (Functionality moved to the \"AZM\" annunciator)
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The AZM activation condition has been changed to only activate on thermal power going over 3450 MWt, along with AR(M) related trips
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Swapped the AZM and AZMM annunciator positions for consistency
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The \"Thermal Power\" automatic AZ-5 reason has been retired
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Other Changes

Non-AZ control rods upwards movement is now locked until all AZ rods are withdrawn
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Channel ruptures can now occur due to pressure caused by high reactivity situations and meltdowns
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Xenon calculations have been completely revamped and now behave in a significantly more realistic fashion (Still sped up for gameplay)
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AZS and AZM signals will now continue for 3 seconds (even after the root cause is no longer valid)
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The rod control lever is no longer artificially locked during AZ-5
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Changed the USP rods to be completely independent of AZ-5 allowing them to be manually moved during it
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UZS(R) no longer randomly malfunctions
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UZS(R) now malfunctions due to extremely low period, high reactivity and extremely high thermal power
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Severe UZS(R) malfunctions can now cause the sensors to violently output erratic data
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Improved temperature calculations significantly
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Changed the SFKRE \"Overloaded\" state slightly
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\"MCP Overheat\" automatic AZ-5 reason retired
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\"Manual AZ-5\" automatic AZ-5 indicator removed due to redundency
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All instances of \"MCP AZ\" changed to \"MCP Trip\"
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Condensed the \"MCP Trip\" automatic AZ-5 reasons into 1 for each loop (was 8 total)
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Added \"MCP Flow Low\" automatic AZ-5 reasons (one for each loop)
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Added \"Channel Leak\" automatic AZ-5 reason (Triggered by channel ruptures and meltdowns)
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Modified the reactor meltdown conditions
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Modified the reactor explosion conditions
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The reactor now updates every frame (Was originally at a fixed 0.05 seconds)
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Changed the graphics of the pointer slightly
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Remade the selsin code in order to be smoother and to avoid bugs
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Changed all buttons to share the same SFX
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Removed the heavy mouse smoothing effect
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Adjusted the order of some annunciators and indicators
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Renamed the \"PK-RR Out of zone\" indicator to \"PK-AZ Out Of Zone\"
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Changed the \"PK-AZ Out Of Zone\" indicators color from red to yellow
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Renamed a few indicators
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Renamed a few of the automatic AZ-5 cause indicators
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Updated the in-game music slightly
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Misc changes

Redesigned the settings menu
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Added the ability to filter password protected lobbies from the lobby browser
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Selecting a lobby no longer blurs out the background (allowing you to click on other lobbies without having to press the \"cancel\" button)
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Modified the menu music to change depending on which section you\'re in
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Added a new overlay when joining a server is slow (Similar to the \"Spawning Player\" overlay removed in 1.0.1)
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Challenge modifiers are now displayed when selecting a server
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Bug fixes

Fixed an issue that caused the reactor to explode when it wasn\'t supposed to
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Fixed an issue that occasionally caused the reactor thermal power to increase infinitely after a full shutdown
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Fixed an issue that lead to inaccurate period values being displayed at higher power
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Fixed the multiplayer optimisation issues
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Fixed several multiplayer desync issues
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Fixed a bug that sometimes caused all rods to appear as \"selected\" after canceling AZ-5
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Fixed a bug that caused a bugged error string to appear when being disconnected from a server
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[ 2025-09-14 14:44:58 CET ] [Original Post]

1 year of RNPS!

RNPS\'s 1st birthday

It\'s officially Rasvyats first birthday! To celebrate this milestone, I\'m doing a 15% off sale. It\'s been a pretty crazy year since the release of the game, and I genuinely appreciate every single one of you :)

RNPS 1.0.2

As those of you inside of the Discord server will know, I\'m releasing another RNPS patch based on the original 2022 legacy codebase as a way to return to development from my break (Which I will elaborate on later).\n\nThis update isn\'t going to be anything too flashy, however it will be heavily revamped under the hood (albeit nothing even remotely close to 1.1), with significantly better performance, multiplayer improvements and even a couple reworks, and I expect it to be releasing in the next week or so.

Developer Livestreams

Another repeat from the Discord server, however I\'m announcing that at some point after the release of 1.0.2, I will be doing live streams on YouTube while I develop the game. In these livestreams I will show the progress of 1.1, along with answering your questions about the game and where it will be going.

The RNPS Creator-Rewards program

As a simple incentive for those looking to make YouTube videos on RNPS, I will be paying out rewards (in Steam Gift cards) based on the amount of views you receive, ranging from 5 AUD, up to 105 AUD.\n\nFor more information on this program, early teasers, smaller announcements and to be able to chat with me and the community, check out our Discord server.

Why did I take a break?

This is significantly more personal than I\'d usually get in one of these announcements, however shortly after the release of Rasvyat 1.0.1, I witnessed the first death in my family, I will not be going into any details here as it would be extremely disrespectful, however this hit me extremely hard and I wasn\'t in any position to develop the game for a few months. Despite this, I\'m feeling a lot better (despite obviously not being at my best), as a result I resumed work a couple weeks ago, and I\'m looking forward to releasing 1.0.2, and getting started on 1.1

[ 2025-07-18 13:54:25 CET ] [Original Post]

Why did 1.0.1 take so long and what comes next?

Around a week ago I released the 1.0.1 update, and upon doing so many of you were probably disappointed by how little the update actually added in comparison to how long it took, so I thought I'd shed a little light on why it took so long, the rough history of the game, the development issues and what you can expect for future updates.

Pre-release History

I started making this game in September 2022, in this stage of development, I was not going for realism, but rather for simplicity, the game only had a total of 3 buttons, those being "Raise Control Rods", "Lower Control Rods" and "AZ-5", there were no pumps, no water, no temperature, just the thermal power and incredibly basic rods, even the flux and thermal power was more simplified than what we have today, in that it was either always decreasing, stable or always increasing.

At some point in early 2023, I begun to shift my focus from simplicity to slightly more realism, around this time I implemented an extremely basic pump and water system (Far more reminiscent of a BWR than an RBMK), along with more annunciators for you to observe, at this stage the game still had very little basis on reality in regards to the controls, layout or anything else.

Over the next year (2023 - 2024), I began to improve the game pretty regularly, by March of 2023 (Almost exactly 2 years ago at this point), I had created the basis of the control rod system that is still used today, this being the first system to be actually based on reality, by May I'd implemented the Narrow Profile Gauges and updated various models, making the game look closer to how it does today, by September of 2023 (1 year after I began), I laid out the foundation for moving the game from a singleplayer game to a multiplayer game and even did the first multiplayer test with 3 others, by November of 2023 I'd updated the physics of the reactor to behave far more closely to how it does today, no more of that either constantly increasing or decreasing system.

From January of 2024 through to the initial release in July, I updated the models of the buttons and switches, I updated the lighting, and most importantly I hired my first developer to flush out the control room into a decent recreation of Chernobyl Unit 4.

Development Struggles

Despite how much progress and success I experienced in the first year of development especially, by late 2023 and even moreso 2024, the cracks really started to show, it became more and more obvious that the game couldn't handle the amount of things being added to it, along with all the modifications of year old systems originally created when the goal was simplicity, however I tried to push through these issues.

By the time of June 2024, the project was near impossible to update easily, new features would break things untouched since 2022 and the performance was getting worse and worse, despite this I managed to get the FPS to a semi-stable 70, so I continued, but then came the control room update, this singular update managed to lower the FPS from 70, to 15, and at this point it was early July, 2 weeks until the already delayed release date, so I gutted several things graphically, along with doing my best to optimise the now 1 and a half year old codebase, due to this I managed to get the game up to around 30 FPS by the time of release, and I told everyone that I'd do my best to release some quality of life changes, bug fixes and performance updates in the coming weeks.

1.0.0a

At this point, I had begun work on the 1.0.0a update, I fixed several things from physics issues, to gameplay cheeses to obscure bugs, yet even a month later I couldn't seem to fix the spawning player bug, I searched and I searched to try and find any idea as to what could be causing it, and the only possible thing I found was that it was an issue with how much was being loaded at once, so I began to make some changes to the way things were loaded, and then Unreal Engine crashed, I tried to re-open the project and it gave me a vague and weird error, eventually though I managed to get back into the project a couple days later, and when I got in I found nearly the entire map completely corrupted, leading to the eventual abandonment of that update, as even the backups were screwed.

1.0.1

At this point I begun work on what would eventually be named the 1.0.1 update, this update was fully back to square one, using the original 1.0.0 source code as its base, and due to a combination of all of the previously mentioned development issues, I was able to fix nearly everything except for the spawning player bug, and eventually, after months of work I finally managed to modify the loading of the game and increase the optimization without breaking and corrupting half the game to the point multiplayer was working again and the game was running slightly better, I continued to try to optimise the project more, however this lead to a scare in which the project broke temporarily, however I managed to recover it this time as the corruption wasn't as severe.

And after nearly 6 months following the 1.0.0a update being corrupted, I finally released the 1.0.1 update publicly.

What comes next?

Due to all the aforementioned issues with the 2022 codebase, I've made the decision to move on from it, this does not mean that I am abandoning the project, it does mean however that I will be fully rebuilding the game from the ground up, this is not a new game, merely a massive update under the hood, this means that the next update will take several months, however this will allow me to not only put out future updates faster, but to better optimise the game, and to allow far more complex systems to be implemented.

Thank you all for taking the time to read this and I hope it's helped explain the struggles of making this game, along with the future plans for this project :)

(If you have any feedback, feel free to leave it in the discussion or community Discord server)

[ 2025-03-05 05:35:55 CET ] [Original Post]

Version 1.0.1 | Small Update

New content

Added an optional tutorial to also help newer players
Added optional challenge modifiers for players who have started the reactor at least once
Added various extra labels to help newer players
Added some extra annunciators to reduce some confusion

Gameplay changes

Added an "Anti-cheese" to the AZ-5 malfunction system in order to prevent players from being able to force it with an auto-clicker
Added the "System wear" mechanic, a simple system that slowly increases the likelihood of a malfunction occurring the longer you go without one
Slowed the rate iodine decays into xenon slightly
Slowed the rate xenon decays from the reactor drastically
Slightly modified the conditions for control rod jamming

Misc changes

Updated outdated UI elements to be more coherent with the game theme
Modified some annunciator text
Updated several music tracks used in game
Changed the colours of some game objects
Disabled some misleading indicators belonging to unused systems
Removed the "friends only" option when hosting a lobby due to issues
Added the ability to password protect lobbies

Bug fixes

Fixed the spawning player bug
Fixed a bug that caused the USP selsins to not light up when fully withdrawn
Fixed a bug that caused the SIUB warning alarm to randomly activate
Fixed the centering of the text on some UI buttons
Fixed some switches using the wrong sound effects and models
Fixed most malfunctions accidently being disabled
Fixed an exploit with the KOM switch that allowed players to bypass the rod selection limit

[ 2025-02-25 04:01:04 CET ] [Original Post]

Testers

Hello!

I've been working on RNPS a lot over the last few weeks, and I'm looking for some testers to help me test some things here and there, however I should make it very clear that being a tester doesn't mean you just get early access. You'll be preforming some somewhat structured tests in the game in which I explain the basic direction I want you to go, and then you do it, explaining everything you do along the way and reporting any issues you find, along with providing feedback on things such as preformance, gameplay and overall changes.

You can apply to be a tester on this google forms page here

https://forms.gle/SGbU8aKb4VBSqyhv8

[ 2024-11-05 10:38:20 CET ] [Original Post]

Development issues

I'm sorry for all the issues that are happening with Rasvyat at the moment, such as the
"Spawning Player" bug, or the horrible optimization and the numerous other bugs.

I'm genuinely doing my best to fix them as I care about this game and about all of you, but every fix I do just causes another bug, and so on so on, meaning 1.0.0a may take a while, even other random bugs are popping up out of nowhere as I develop this update with no logical explanation or fix in sight, such as all inputs completely breaking after closing the settings menu in-game.

I'm trying my utter best, please don't think that I've given up, I really haven't, it just may be a little while until I can get this update out.

[ 2024-07-25 13:07:01 CET ] [Original Post]

Rasvyat is now out!

Rasvyat has released 3 days late, sorry for that, however it is now out, there's currently no in game tutorial, sorry, however the game is now available.

There are currently a lot of bugs however they will be resolved in the coming weeks, there is a multiplayer issue where the player may get stuck on the "Spawning Player" screen on some lobbies, the only real solution currently is to press ALT - F4 to force exit the game and host your own lobby, sorry for any inconvenience.

[ 2024-07-17 18:09:19 CET ] [Original Post]

Final Progress Report Prior To Release

Preparing for release progress report

I have hired my first map builder to help out, Ade, because of Ade the release will have a fully flushed out control room.

Beyond this, I have added several new things myself:

A new pump system which will be finished at some point after release
New button and switch models to replace the old blocky placeholders
Basic xenon simulation
New alarm sounds

Unfortunately, since I now have someone else working on the project with me, and because I will be hiring more developers in the future in order to rewrite several older parts of the game, plus getting out updates quicker, I have decided to make the game paid on day one. To make up for this, I will be giving away 30 free keys on launch day in my Discord server, along with this, I'm going to be making the game 40% off for the first week after launch.

Thank you all for sticking around with me for the past 2 years as I've developed this game, it's really been an awesome experience and I hope that you enjoy the game!

[ 2024-07-11 20:00:54 CET ] [Original Post]

Version 0.12.4 | Bug fixes and malfunctions

Content

Random Malfunctions, UZS and UZSR sensors, AR, and AZ-5 can now malfunction.
Added some new annunciators.

Changes

Modified some annunciator functionality.
Changed blackouts to run on the same logic as malfunctions for consistency.
Changed EPS cover SFX.

Bug Fixes

Fixed a bug that caused the reactor period sensors to become desynced on the client.
Fixed a bug that caused EPS cover positions to become desynced.
Fixed several issues with the selsyns.
Sprinting works again.

[ 2024-05-13 10:35:04 CET ] [Original Post]

Version 0.12.3 | Bug fix, quality of life, and feature update.

Content

Automatic shutdown systems are now re-enabled.
Pumps now wind down far slower.
Channel ruptures can now be heard from the control room.
Modified the conditions and worsened the affects of a channel rupture.
Added a new pause menu and settings menu.
VSync can now be enabled.
Your FPS limit can now be changed.
Added player nametags.
Added a new music system (Unfinished).
Added functionality to the annunciators on the SAOR panels.

Bug Fixes

Reactor period sensors now work again.
Fixed various switches not working correctly on the hosts end.
Fixed various server backend functions.
Fixed many issues with voice chat, you should be able to speak in game again.
Fixed a bug that caused the players mouse to be in the wrong input mode in certain situations.

[ 2024-05-09 07:22:59 CET ] [Original Post]

Release Date

As previously announced, the release date was delayed to June 30th, however this unfortunately clashes with a Steam sale which would affect the games visibility on release day, which would mean less players and a worse experience overall.

As a result the final date is July 15th, 15 days more than the original voted time.

[ 2024-04-25 09:04:47 CET ] [Original Post]

Release HAS been delayed

Hello everyone, as the title states, Rasvyats release date has been delayed. Previously I made announcements on Steam, Discord and YouTube asking if you wanted to delay the initial release due to development being behind schedule, and the majority of you HAVE voted for a delay, meaning the game is now going to release on June 30th to allow me more time to finish the game and implement more features.

[ 2024-04-20 09:40:46 CET ] [Original Post]

Release date

The game is currently in a buggier state than expected around the general time of release, I could release it now in its current state, however this would lead to the game having many unfinished features and completely broken things as is, I'm currently running very low on time to actually get the game ready for release and do not think I'll be able to.

However as I've already promised a release date (April 26th) I'll leave it up to you all to vote on if you want the games first build delayed or released on the expected date. I'm very sorry for all of this, I just want the game to be as good as possible for you all upon release, rather than giving a completely broken build.

To make your opinion count, you can vote on this poll

https://forms.gle/C4KdDtCn3yRae3QSA

[ 2024-04-13 06:40:23 CET ] [Original Post]

Game update / information

This is a pretty small update for the game its self, there are very few things of note, however these are the changes:

Updated the login screen with a nice new animation and the actual game logo
Made some changes to multiplayer to improve the server list
Removed debug buttons from the control room
Fixed player nametags

Important information:

The game isn't going to be receiving any updates on the main branch for a while, from now on smaller updates purely for testing that may break things will be posted to the private test branch, instructions on how to access this will be posted in the testers channel on my Discord server, if you are not in the Discord server, please DM me, my tag is thxtnt

[ 2024-03-24 04:04:45 CET ] [Original Post]

Multiplayer Fix

Multiplayer has been fixed, I've also added voice chat, however I haven't tested it yet, please let me know in the Discord if it works.

[ 2024-03-19 13:40:59 CET ] [Original Post]

Warning

The game is broken as hell right now, I've got the game set to debug so I can have logs to figure out what the hell is going on with the multiplayer -_-

[ 2024-03-17 07:17:07 CET ] [Original Post]