Anomaly expansion and update 1.5 announced!

Posted March 13th, 2024 by Tia Young

Sanity-shredding perils abound in this new horror-themed expansion

We’re super excited to announce our new horror-themed expansion, RimWorld – Anomaly!

This expansion adds all manner of monstrous, mysterious, and maddening threats, containment facilities to capture and study dark entities, and a new reality-twisting endgame. Anomaly releases in one month!

We’re also announcing the upcoming update 1.5 to the base game (which will be released at the same time as Anomaly). You can currently test this update on the unstable Steam branch – see the bottom of this announcement for details. (Note that this is only base game content – Anomaly is not yet available.)

We’ll be releasing more info about Anomaly in a series of blog posts over the next few weeks.

Spoiler warning: Below is a high-level description of the expansion content. There are some spoilers here.


The expansion begins when your colonists accidentally provoke a mad superintelligence. From then on, madness manifests: Monstrous creatures, mind-bending mysteries, infiltrating parasites, and sanity-shredding phenomena that twist the whole world around you.

Inspired by classics like Cabin in the Woods, The Thing, The Cthulhu mythos, Hellraiser, and many more, Anomaly goes beyond fighting monsters. This expansion presents ominous, puzzling, mind-controlling, and earth-shaking threats to build your personal horror story.

Some of the twisted scenarios you’ll encounter:

  • At night, hear the screeching of a psychically-invisible hunter that feeds on human souls. Build proximity alarms to detect when it’s near, but you can only fight it when it chooses to reveal itself. Chip away at its health every time it returns, and collect and study chunks of its flesh. Turn the tables, become the hunter and kill it where it sleeps.
  • A massive flesh creature is growing across the landscape, consuming and covering the whole map with a quivering mass of meat. It defends itself with beasts and acid. Fight it to get samples of its nervous system, then study them until you can venture to its heart and kill it for good.
  • A parasite has mind-controlled some of your colonists – but who? They pretend to be human as they work to infest others. Track evidence, imprison, interrogate, and medically test people to find out who is infested before it’s too late.
  • A pulsating obelisk crash-lands near your base. You can try to suppress its filthy energy, but the obelisk may lash out and violently mutate your people, copy them endlessly, or abduct them to an endless gray maze.
  • Your colonists become obsessed with a beautiful golden cube, one by one. They build statues of the cube. They worship the cube. They love the cube.
  • A corpse arrives that looks exactly like one of your colonists – and seems to follow them. No matter what you do, the corpse returns…
  • And many more weird and horrifying events!

Horror combat

You’ll fight battles against shrieking fleshbeasts, hordes of shambling undead, spherical death-machines, massive devouring water-beasts, lumpen imitations of human beings, and many more nightmarish perils. Use the monsters against your normal human and mechanoid foes where you can!

Construct new tools and gear to help you – flamethrowers and hellcat rifles, IEDs that resurrect the dead, flesh-mutating pulsers that transform living creatures, insanity-inducing weapons, and crossbows that stun your targets.

Capture and study entities in your facility

To defeat the monolith’s manifestations, you must gain their power. Build a grand containment facility so you can capture monsters, study them, and exploit them. Expand it with stronger walls, floors, and doors to keep them secure. Exploit your captives to use their power against your enemies – but don’t push them too far!

Harvest the new bioferrite and shard resources from your malevolent menagerie to use in experimental serums, psychic rituals, ghoulification surgeries, and void-powered constructions.

Fight the cultists who serve the machine-mind

Macabre cultists will attack and perform their psychic rituals with suicidal commitment. They may stand in rows, or chant around a ritual circle, or whisper hateful psychic curses against your colony. Destroy them before they summon bloody beasts, abduct your people, or drive you mad with psychic influence.

You can use the same rituals for your own purposes. Summon the massed dead, rain rage-filled blood, connect with the void, steal the minds and health of your foes, and more.

Choose your fate in a new endgame

In the end, the abyssal void will swallow the world and you must choose your fate.


Ludeon Studio’s founder Tynan on why he decided to make Anomaly:

“I wanted to give players new kinds of emotions they haven’t encountered before in RimWorld. We’ve explored feelings around dramatic combat tension, family warmth, problem-solving and many more. Now I wanted to provoke new emotions – dread, psychological tension, suspicion and mystery. The horror theme unlocks a new emotional landscape for us to explore.

There aren’t many games which mix management and horror either, so it was an interesting design challenge to marry these two elements.

Plus I saw Cabin in the Woods and I thought the monster lab was awesome.

It was important to me that this not just be a collection of monsters to shoot at, because the base game already generates those feelings of combat tension and I wanted something new. So we made sure to design the new threats to follow the arc of classic horror stories: The protagonists encounter a mystery, then realize it’s a threat, and try to survive while they learn more about it, slowly building advantage before they try to turn the tables. It’s a very RimWorld kind of chaos when several of these things are happening at once with different threats.

This was really fun to work on and I think the team did an awesome job – I can’t wait for everyone to play it.
– Ty”


We have a lot to say about update 1.5 – it’s been nearly 18 months of work!

If you’re interested in trying update 1.5, you can play on the unstable Steam branch. To get access, go to your Steam library, right-click RimWorld and select “Properties”, then select the BETAS tab and choose branch ‘unstable’. Restart Steam if your game does not automatically update.)

Modders should be able to use this public 1.5 unstable branch to update their mods before update 1.5 is released to everyone next month.

Read the full 1.5 changelog here (18 pages of changes!) or read the summary below.

Books, bookcases, couches, ornate doors: There are now books for your colonists to read, and bookcases to store them in! Books are great for recreation and for their unique bonuses: textbooks increase a specific skill, schematics progress a certain research project, novels increase recreation faster, and tomes progress an Anomaly-specific research project. You can obtain books from traders or as quest rewards. Storing books in bookcases increases the beauty of a room, makes nearby research benches faster, and increases the XP and recreation gained from reading.

Couches function like armchairs but now have room for two! And ornate doors are the first 2×1 door in RimWorld (it took some work for the system to support doors that weren’t 1×1!). They’re very fancy and suit throne rooms, temples, or other prestigious buildings.

Wall lamp, flood lights, and hidden conduits: Yes, you can now put lights on your walls and hide your conduits! Wall lamps and wall torches can be placed directly on walls. They function like a floor lamp or torch would, but with a little less light. Flood lights are very powerful (and expensive) outdoor lights that cover large areas, which saves you from building several small lamps. Hidden conduits are useful for two reasons: they’re harder to damage from explosions or fire, and they’re invisible to the player unless you’ve got the power/building UI turned on.

Performance improvements: We’ve continued to work on optimizing RimWorld’s performance. Pawns (characters and animals) are now drawn in parallel on a separate thread, the pawn render system was rewritten to allow for easy addition/removal of visuals, and lots of optimizations were done on alerts, beauty calculations, and pen animal food-searching behavior.

Crawling: When downed, humans can now crawl on the ground! Crawling colonists leave blood trails, move away from danger, and will seek out the nearest place to recover, like a hospital bed or sleeping spot. You’ll see enemies crawling around too. It’s rather dramatic.

Possessions from traits: When choosing your starting colonists, there’s now a chance for them to spawn with possessions related to their traits. For example, a psychopath might carry a human heart, or a pyromaniac comes armed with molotovs, or someone who’s greedy could have pockets full of gold.

Mechanoid water emergence and slag chunks: Did you think the water was safe? Mechanoids can now surface from bodies of water, which requires adapting to oceans and lakes when building your base’s defenses. Also, certain large mechanoids have a chance to drop a “mechanoid slag chunk” when they’re broken down – these act like steel slag chunks and can be smelted for steel.

Bionic jaws and organ decay: Sometimes colonists lose their jaws in a terrible accident, but they can now be replaced with the new bionic prosthetic. Keep an eye on your colonists’ organs too – there’s a chance they may develop a very rare organ decay disease.

“Mine vein” designator: This command orders colonists to mine out a whole mineral lump in one click. For example, if you just want to mine gold ore and want to ignore the surrounding rock, the “mine vein” tool tells colonists to mine all the visible gold plus any gold that gets revealed in the process.

Clean room: Selecting a colonist and right-clicking a room that’s dirty now gives you the option to clean the room. This is far more convenient than manually clicking dirt on the floor and queueing up cleaning actions.

New wanderers after a “game over”: When all of your colonists are dead or gone, there’s a new option as part of the game over letter to “create new wanderers”, if you want a second chance with your colony. This allows you to create 1-6 new colonists to inhabit the remains of your colony instead of ending the game. This is entirely optional and you don’t have to use it if you prefer a more hardcore experience.

Search function: In the bottom right corner, there’s now a magnifying glass icon and a search bar you can type in to find items, structures, enemies, etc. on your map. No more losing items! The default hotkey is “Z”.

Tainted apparel visual changes: Tainted apparel (clothes worn by someone that has died) now has a distinct, darker color. Previously, it was easy to mix up tainted apparel with non-tainted apparel.

UI improvements: There’s an option to make colonists’ moods on the colonist bar much more visible. When you zoom out very far, pawns become highlighted so they’re easier to spot on the map. We also redesigned the prisoner and health tabs and improved the research UI and policy UI for a better experience.

Art improvements: There’s new and improved weapon art. We also added new immature crop art and leafless tree art for the plants missing those.

Miscellaneous: There are lots of smaller things that were done for 1.5 (see the 18-page changelog), including an option to capture carried pawns without having to drop them, improved construction hauling, and better firefighting.


Please wishlist Anomaly!

And stay tuned for our Anomaly feature blogs as we approach release day (which is in one month)!

Anomaly has more content than any previous expansion. We expanded the team and worked for 18 months on this expansion and update 1.5, so it’s got a lot of passion in it!

Anomaly adds new feelings to RimWorld. It creates moments of terror, new roleplaying opportunities, unforgettable stories, and a unique narrative experience for every player. We seriously cannot wait to let you get your hands on it.

In the meantime, we’d love to hear what you have to say about Anomaly and update 1.5!

  • Join the discussion on Reddit
  • Share your thoughts on X (formerly Twitter)

If you’d like to help us test the 1.5 unstable build and report bugs, please join the official RimWorld Development Discord.

See you soon!
Ludeon Studios

Get 20% off when you buy the game bundle, or 20% off the game you don’t own to complete the set!

The RimWorld & Medieval Dynasty bundle is now available:

Survive through time! Begin in the Middle Ages and endure hard yet wonderful times, then continue your adventure on a sci-fi Western-themed world in the far future! Medieval Dynasty meets RimWorld – a unique opportunity to experience both of these top indie hits.

About Medieval Dynasty: Hunt, survive, build and lead in the harsh Middle Ages: Create your own Medieval Dynasty and ensure its long-lasting prosperity or die trying! Play alone or team up with friends to enjoy the ultimate medieval experience.

About RimWorld: A sci-fi colony sim driven by an intelligent AI storyteller. Generates stories by simulating psychology, ecology, gunplay, melee combat, climate, biomes, diplomacy, interpersonal relationships, art, medicine, trade, and more.

Good luck on your medieval and sci-fi adventures!

Winter Sale, Merry Christmas and Happy New Year!

Posted December 21st, 2023 by Tia Young

Tis the season to be merry!

We had a great 2023 together with you guys! Thank you for sharing your love for what we’ve all created. We see your mods, art, writing, videos, screenshots, Reddit posts, lore analyses, bug reports, comments, suggestions, Steam reviews, memes… all of it!

In 2023, we released our first ever official plushie (the Thrumbo), the Ideology expansion came out on consoles, and our team grew again. Also, RimWorld turned ten years old in November – that even surprised us. How can time go by so quickly?!

You can find us at the official RimWorld development Discord where we test and submit bugs, on the RimWorld subreddit, or at the Ludeon Studios twitter. Please don’t hesitate to leave RimWorld or its expansions a Steam review if you enjoy them!

Merry Christmas, Happy Holidays, and Happy New Year!
Ludeon Studios

RimWorld’s second expansion, Ideology, is out now on Xbox and PlayStation!

The Ideology expansion gives every person in the game a belief system. Expand your RimWorld Console Edition experience with a ton of new additions and features! Everything is customizable. You can build mind-bending temples, hold unforgettable rituals, hunt the venerated relics of your belief system, and seek transcendence beyond reality in the new, epic archonexus endgame.



Rare plushie thrumbos have wandered into the area!

Posted April 27th, 2023 by Tia Young

Get your own Thrumbo plushie!

Hello! We just launched these adorable plush thrumbos on Makeship! They’re delightfully fluffy and only available for a limited time – the campaign ends May 17. (They’re also our very first official RimWorld merch.)

Get your own thrumbo before they move on:

Something cute has wandered into the area!

Posted April 25th, 2023 by Tia Young

Announcing an adorable collaboration between RimWorld and Makeship… coming soon!

See you on April 27!

Update 1.4.3704 released

Posted April 19th, 2023 by Tia Young

Hello hello! There’s a little update today that fixes a bug where colonist assignments were removed when you entered a caravan, plus some other useful changes. 🙂

Changelog is below! And if you encounter a bug, please share it over on our Official RimWorld Development Discord.

Cheers! – Tia


– Clarify that pawns with no xenogenes cannot implant their xenogerm into another person. Show correct warning message on attempt.
– Updated psychic bonding hediff tooltip to factor in pawns contained in buildings.
– Updated player name-in-game content.


– Fix: Load stack count is incorrect for caravan itab when there is only one thing in the transferable and the player isn’t taking the whole stack.
– Fixed some typos.
– Fix: Magenta square fetus graphics when reloading.
– Fix: Pawns leaving map have their assignments reset.
– Fix: Error on corpse destruction when completedObligations is null.
– Fix: Gibbet cage description mentions they are made of “steel” but can actually be made of any metal.

We’ve got great news for our console RimWorld fans: The Ideology expansion is coming out in April this year!

If you didn’t already know – RimWorld Console Edition is available on PlayStation and Xbox!

Read all the details over here:


Update 1.4.3682 released

Posted March 28th, 2023 by Tia Young

Spring is here, so we’re springing into action with a (small) update of fixes for RimWorld and its expansions.

The changelog is below, but here are the highlights! We fixed an issue where captured prisoners were escaping from your caravans and another issue where siblings became unrelated to each other if their parents were removed from the game.

If you like following these updates, you’re welcome to join us and even test new builds over at the Official RimWorld Development Discord!

Enjoy! – Tia


– The bestowing ceremony lord will now be removed once the last pawn has left the map.
– Removed 2 second damage stagger from tunneler mechs. Staggering is based on weapon stopping power as with all other pawns.
– Update previous passion values if a child growth moment picks a skill with passion dropped by gene.
– Pawns that generate with passion-dropping genes will no longer generate with passion for those skills.
– Updated player name-in-game content.


– Fix: Incapable of violence pawns can activate rocketswarm launchers.
– Fix: Error when shield belt on ground is hit by EMP explosion.
– Fix: Captured prisoners escaping from reformed caravans.
– Fix: Slaves freed on exiting map.
– Fix: Ranged weapons that don’t do bullet damage don’t display “Headshot” text on head hit.
– Fix: Dead calm pawns go berserk when arresting fails.
– Fix: Embryo skin color not preserved in growth vat between save/load.
– Fix: Pawns incapable of manipulation are able to strip targets via float menu option.
– Fix: Caravans holding relics cause “relic lost” thought on map exit.
– Fix: Rare exception occurring when attempting to start a queued job with a null def.
– Fix: Rare error when attempting to dye buildings.
– Fix: Items in fogged areas counting as complete for bills.
– Fix: Invalid destination for shuttle causes errors.
– Fix: Pollution overlay grid not updating after cell-filling buildings are destroyed.
– Fix: Pawn sibling relationships disappearing when parents are removed.
– Fix: Long range mineral scanner tune command has no description.
– Fix: Hard-coded English string “No description.” for commands without a description.
– Potential fix for TKey system suggesting long-form translation aliases.
– Fix: Missing period in legionary description.
– Fix typo: “Do really want to hack…”
– Fix: Awkward wording in dirtmole description.

Update 1.4.3641 released

Posted February 15th, 2023 by Tia Young

Hi again, just dropping by with another small update. We addressed some issues with Biotech and fixed a UI scaling issue that occurred when players had DSR enabled. (UI was way too big!). The changelog is below for you to read.

The update is small and should be compatible with all RimWorld savegames and mods.

Just a reminder that you can share any bugs you find and even help us test builds on our official RimWorld Development Discord! Our community helps us a ton with getting these updates and fixes out quickly. 😀

Until next time! – Tia


– Betrayal quests now fail once all the surviving refugees have joined your faction instead of just any.
– Don’t display owner types for cribs since cribs don’t have their owner types changed as the room changes.
– Updated name-in-game content.
– Colonists can now put unadopted babies born to prisoners in cribs.
– Moved speech letter translation keys to Core from Royalty.
– Allow rescuing babies, even if they are from a hostile faction, without having to adopt them first.
– Ageless gene stops aging progress at 18.5 instead of 18.
– Unassign beds from pawns that have grown too large to fit in them.
– Added an alert for babies from other factions which have no local caregivers and can be adopted.
– Moved some speech-related translation keys from Royalty to Core.


– Fix: Recommended screen resolution incorrect when using DSR.
– Fix: UI scale resetting to higher numbers for monitors with height below expected values. (eg 1280×720)
– Fix: If a child goes through a growth moment expecting passion increase choices, but there are no available passions, the UI will lock.
– Fix: Errors when trying to bring a baby to a mom inside a container to breastfeed.
– Fix: Colonist in labor letter doesn’t have look target set.
– Fix: Error on releasing space refugee prisoners.
– Fix: Pawns considered free when using shuttle/pods, causing “Relic lost” thought if equipped.
– Fix: Generated immediate family relationships unable to generate.
– Fix: Fabricors not making medicine.
– Fix: Paramedics not fighting fires automatically.
– Fix: Apparel that can be made of any non-smeltable stuff does not show up on the smelting bill UI. (Eg plate armor)
– Fix: Permits not reset when royal pawn dies, has title inherited, then is resurrected.
– Fix: Psychic suppression targeted by healer mech serum.
– Fix: Mech global work speed is affected by darkness. Inconsistent with move speed.
– Fix: Error when non-human pawn reaches growth moment age.
– Fix: Exception when trying to get mech with no energy need for tooltip in niche circumstances.
– Fix: Inactive sterile gene affects fertility.
– Fix: Gauranlen and polux seeds can be planted on hydroponics basins and plant pots.
– Fix: Beard and genes offset incorrectly based on rotation in some situations.
– Fix: Growth stat appearing on humans.
– Fix: Lancer shoulder parts labels inconsistent.
– Fix typo “crytosleep”.
– Fix: Typo in config error when pawn kind appears in more than one BossDef.
– Fix typo: “means that so”.
– Fix typo “forth body ring”.