Ongoing progress

Posted November 12th, 2015 by Tynan Sylvester

Hello everyone! As I’ve mentioned in previous posts, I’m still on a bit of a break here until early next year. However, I just wanted to update you on our ongoing progress.

With the magic of laptops and Internet, and excellent work from coding prodigy Piotr ‘ison’ Walczak, progress on the game itself is continuing at full speed even while I’m not at home. Currently I’m working something like quarter-time on finance, business, game design, PR and code consultation, while Piotr provides most of the mental muscle and keystrokes to actually write and refine the code. The end result is that we’re adding features almost as fast as we ever have.

We work iteratively, so things change a lot, often in unexpected ways. So I won’t go into detail about exactly what’s being added. But I can offer some generalities. So far, we’ve added:

  • Self-reproducing, spreading underground insect hives
  • Social relationships with friends, rivals, family, chats, arguments, and fights
  • Many more animals, some of which will hunt people
  • “Components” resource used for machinery and electronics
  • Ground-traveling trade caravans from other factions
  • Character records which keep stats on each character like number of kills, injuries, surgeries, etc.
  • Extreme desert biome

I appreciate all discussion but please don’t ask for more details on these! Check the FAQ for more info on why we don’t release detailed descriptions of unreleased designs.

I’m afraid there won’t be any releases until I’m back. I want to be fully present to manage the tricky and sometimes hectic process of testing and release. So I’m sorry you won’t see these goodies for a while. But that should mean the next version will be a bigger content jump than any before.

RimWorld original soundtrack by Alistair Lindsay released

Posted October 28th, 2015 by Tynan Sylvester

Alistair Lindsay’s original soundtrack for RimWorld is now available for purchase!

Check it out here

It includes all the songs in the currently-released game, as well as several that aren’t yet out (but will be included in future builds).

Have a listen. Let Al’s dulcet synth-backed guitar tones accompany you during work, relaxation around the house, or other games without such an awesome soundtrack. You won’t regret it.

Tiny hotfix to Alpha12d

Posted August 29th, 2015 by Tynan Sylvester

I’ve just released a tiny hotfix. For compatibility info and how to update, see this post on hotfixes.

This is just a balance update to solve issues with unlucky flashstorms ending the game in a rather un-entertaining way. The only change is:

  • Flashstorms are much less intense

This bring the game version to Alpha 12d, build 0.12.914.


A Man and His Dog

Posted August 27th, 2015 by Tynan Sylvester

Fan video by IskOtter.

Hotfixed to Alpha12b (now Alpha12c)

Posted August 26th, 2015 by Tynan Sylvester

I’ve just uploaded a hotfix to version Alpha12b. This is purely a fixing and balancing hotfix.


  • Your saves from A12 should still work. Hooray!
  • Data/XML-only mods from A12 should still work. Yay!
  • Mods with code from A12 may work, or they may break. You may need to recompile them with the new DLL. Aww.

To get the update: Download using your previous link from your last email and install to a clean empty folder. There will not be a new email sent. Your personal download link is permanent and always has the latest version. If you need help with anything, please go to

Changes in Alpha12b:

  • Rebalanced animal hauling, traps, charge rifle, assault rifle.
  • Rebalanced animal hunger rates and plant nutritions so animals need larger grass pastures to be sustainable.
  • Thrumbo is much more powerful in combat.
  • Sleeping pawns now wake up when harmed.
  • Float menu column is wider to avoid cut-off text.
  • Ship part incidents won’t occur so early.
  • First raid comes a bit earlier on Cassandra and Phoebe.
  • Fixed: Manual work priorities being used after switching to non-manual priorities.
  • Fixed: Colonists have ‘colonist left unburied’ thoughts when tame animals were left unburied.
  • Fixed: Eggs can only be used for simple meals
  • Fixed: Trade items dropping in weird places.
  • Fixed: Colonists incapable of violence can slaugher animals.
  • Fixed: Alphabeavers leave the map after they sleep because they get hungry.
  • Fixed: Date changes over at 6am, not midnight.
  • Misc other fixes and improvements.

Change in Alpha12c:

  • Poison ship part event now only drops one ship part instead of 2-3.

RimWorld Alpha 12 – Animal Taming released

Posted August 21st, 2015 by Tynan Sylvester

Animal taming is here! You can now tame animals, milk them, eat them, and train them into whirling furry/scaly death machines! We’ve also added codified room roles and statistics (like room wealth and room impressiveness), new traits, animals, threats, items, bonuses, bugfixes, and bugs. A full change list is at the end of this post.

How to upgrade: If you own the game, you can get the new version by re-downloading from the link you used before (it is a permanent link and always has the newest version). You should also get an update email from us. Anyone still having trouble should start at the support page which includes an automatic link sender tool and our support email. There may be a delay of some hours before your download count resets or your email arrives.

Also note that this build will not load old savegames or old worlds, so please don’t try to load these in the new version. They’ll probably just crash the game.

Change list:

Animal taming

  • Colonists with the Animal Handler work type will now interact with animals.
  • Animal handling success rates are governed by the new Animals skill.
  • Handlers can tame animals. They approach designated wild animals with food and attempt to tame them to make them part of the colony.
  • Handlers can train animals as designated in tame animals’ Training tab. Animal training looks like taming, requires food, and trains one “trainable skill” at a time. Not all animals can learn anything; they need sufficient trainable intelligence.
  • Trainable skills:
    • Obedience: has master, follows master while master is drafted and defends him.
    • Release: master can release animal during combat to attack distant enemies, and call animal back.
    • Rescue: animal will rescue wounded colonists and take them to bed. Animal must be smart and large enough to do this.
    • Haul: animal will intermittently haul items like a colonist would. Animal must be smart enough to do this, and will haul an amount related to its body size.
  • Added Animals main tab, which lists all colony animals and provides interfaces to set their master and area restriction.
  • Each animal has a ‘wildness’ indicating how difficult it is to tame.
  • Animals have a minimum handling skill. Player is warned if they designate taming an animal that no handler can actually tame.
  • Tame animals can be assigned animal areas in which they will try to remain.
  • Tame animals can be bought and sold. Bulk traders carry normal animals, while exotic goods traders can buy and sell any weird animal, pre-tamed.
  • Tame animals can be designated for slaughter and animal handlers will slaughter them.

New animal behaviors and mechanics

  • Some animals (alpaca, muffalo, camel) can be shorn for wool that can be crafted into apparel.
  • Some animals (muffalo, cow, camel) can be milked.
  • Some animals (chicken, cobra, iguana, tortoise, etc) can now lay eggs. Fertilized eggs will hatch. All eggs can be eaten or cooked.
  • Animals can be pregnant and give birth. Animals are made pregnant when a male approaches and mates with a female. Birth is accompanied by amniotic fluid spray.
  • You can now build animal beds and animal boxes and place animal sleeping spots.
  • Animals all sleep.
  • Animals can have different graphics per gender.
  • Animals have “life stages” related to their ages. Baby animals are tiny and weak, juveniles somewhat larger, and adults are full size.
  • Colony starts with a random pet.
  • Animals can nuzzle colonists, improving their mood.
  • Animals can be named when tamed or when nuzzling. Names are drawn from a large bank of animal names.
  • All organisms including animals have life expectancies and will develop chronic conditions like frailty or cataracts in old age.
  • New incident: Farm Animals Wander In (some tame farm animals wander to and join the colony)
  • New incident: Self Tame (random wild animal on map becomes tame).
  • Doctors will treat animals’ wounds if the animal is in a colony bed.
  • Some animals may attack on a failed taming attempt.
  • Animals produce animal filth, proportional to body size, inversely proportional to petness.
  • Tons of new animal graphics and sounds for new animals.

New animals

  • Boomalope (large fragile animal that explodes and sets fires on death)
  • Thrumbo (giant peaceful powerful creature with amazing fur and horn)
  • Chinchilla (very valuable fur)
  • Capybara
  • Cow
  • Pig
  • Chicken
  • Yorkshire terrier
  • Labrador retriever
  • Husky
  • Elephant

Room roles and stats

  • Rooms now have ‘roles’ and stats based on what is inside them. These are automatically-defined values that, in turn, passively affect thoughts and events in the room.
  • Room roles and stats can be inspected with a new inspection tool (bottom right of screen).
  • Room roles are:
    • Bedroom
    • Barracks
    • Prison bedroom
    • Prison barracks
    • Dining room
    • Hospital
    • Laboratory
    • Kitchen
    • Rec room
    • Tomb
  • Room stats are:
    • Impressiveness (most important stat; an aggregate of other stats, mostly for pride psychology)
    • Wealth
    • Space
    • Beauty
    • Cleanliness (has a direct effect on medical outcomes)
  • Room stats affect things like:
    • Immunity gain speed
    • Medical treatment quality
    • Room stats create many variants on thoughts like:
    • Ate in impressive dining room
    • Own impressive bedroom
    • Own bed in impressive barracks
    • Did joy activity in impressive rec room
  • Added traits:
    • Greedy: Unhappy without a very impressive room.
    • Jealous: Unhappy if anyone has a room noticeably better than him.
    • Ascetic: Unhappy unless he has a very crappy room.


  • Added ‘facilities’ – passive buildings that give bonuses to nearby buildings:
  • Vitals monitor (improves healing in adjacent medical bed)
  • Tool cabinet (improves production at nearby work table)
  • Multi-analyzer (speeds research at nearby research bench)

Ancient artifacts

  • Ancient artifacts with psychic powers can be bought, sold, and found in ancient crypts.
  • Psychic powers work at any range through obstacles.
  • Artifacts are one-use.
  • The artifacts are:
    • Psychic insanity lance – drives a single target insane
    • Psychic shock lance – drops a single target asleep
    • Psychic animal pulser – drives animals berserk map-wide
    • Psychic soothe pulser – gives a temporary mood boost to everyone on the map

Graves and sarcophagi

  • Graves are no longer just glorified storage slots; colonists must actually ‘bury’ corpses.
  • Can now build sarcophagi out of solid materials. High-quality sarcophagi are art items.
  • Colonists will visit graves of dead colonists for a joy activity.

Misc new incidents

  • New incident: Poison ship. A variation on the psychic drone ship that kills plants in an expanding circle.
  • New Flashstorn. A localized, intense lightning storm in one area of the map. Causes big fires.

Interface rework

  • Main tabs like Work, Outfits, World, Factions, etc are now tabs permanently displayed along the bottom of the screen instead of being buried in an Overview window.
  • Some tabs, like Work, will not take more space than they need to given the number of entries (colonists) to display.


  • Added heart attacks. People or animals approaching or past their life expectancy will have a chance of heart attack, which will progress and resolve in a random way. Heart attack is emergency-treatable to improve outcomes.
  • Added hay (animal food only, for getting through winter). Added haygrass (long growing, high yield of hay).
  • Added way to enable/deny medicine in different qualities to any colonist, prisoner, or tame animal, from a the health tab.
  • All furniture is now ‘minifiable’ like televisions and telescopes. This means beds, chairs, etc can be moved without being rebuilt, bought, and sold.
  • New trait: Night owl. Happy when awake at night, sad if awake around midday.
  • New thought: Crowded – In a space with too many people.
  • New installable implant: Painstopper. Prevents all pain, but reduces consciousness permanently.
  • New installable implant: Joywire. Large permanent happiness boost, but reduces consciousness permanently.
  • Furniture can now be art engraved.
  • New floors: gold tile, sterile tile, cream carpet, dark gray carpet.
  • Game start now has a “select random landing site” button if you don’t want to choose.
  • Improvements to trade interface: better layout, expands vertically to use all screen space, increment/decrement buttons and launch/drop all buttons added.
  • Added ‘open’ designator for opening cryptosleep caskets, graves, sarcophagi, and other containers.
  • Manhunter pack incident can use animals besides wargs.
  • Commands are shown if there is at least 1 selected object with this command, instead of requiring all selected things be able to accept the command.
  • Dazed broken pawns will now randomly strip off clothes and drop things.
  • New graphics for squirrel and warg.
  • New graphics for research bench and other buildings.
  • Unskilled or injured growers can fail at harvesting, destroying the harvest for one plant
  • A bunch of new music from Alistair Lindsay.
  • Carrying capacity is now a stat that can change for body size and manipulation capacity.
  • Siegers will never be sent with only melee weapons (too exploitable).
  • Sappers now avoid mining through high-health ores and barriers.
  • Rebalanced crop yields and harvesting challenges so crops require a bit more space.
  • Game will auto-reset mods config on startup crash to try to recover.
  • Tons and tons of bugfixes and other adjustments, refactorings, balancings and tunings.

Hotfixed to Alpha11c (Update: Alpha11d)

Posted July 22nd, 2015 by Tynan Sylvester

Alpha11c is a very small hotfix to Alpha11b that fixes a few serious bugs. All save games and mods should still be compatible.

Update: Now to Alpha11d. This is the same as Alpha11c, but the save game location will be correct on Macs. (I originally built Alpha11c against a slightly old version of Unity from before they changed the save game path).

There will not be a new email sent. You can download using your previous link from your last email. Your personal download link is permanent and always has the latest version. If you need help getting your link, please go to


  • Mitigated a game-killing bug caused by corrupted pawns. The corrupted pawn will now be destroyed instead of causing broken saves and game crashes. I’m still tracing the root cause of this so I can make the game not generate corrupted pawns in the first place.
  • Fixed a stuck-pawn bug caused by wardens trying to recruit downed prisoners and immediately ending their job, over and over.
  • Fixed prisoner config resetting at inappropriate times.
  • Fixed floor smoothing speed being determined by mining skill (it’s now construction).
  • Fixed repeated EMP damage canceling stuns in progress.

Quick update upcoming developments

Posted July 22nd, 2015 by Tynan Sylvester

Hey everyone, hope summer treats you well. So here’s the state of development now:

First, players found some rare but game-killing bugs in Alpha 11b. As in, they can actually kill your save game and make it unloadable. I’ll probably be releasing a small, non-essential hotfix to Alpha11 to fix these. This will be a minimal fix with no new content or changes to compatibility.

Second, Alpha 12’s key feature will be animal husbandry and related features. It’s an ambitious update: new animals, animal mating, reproduction, egg laying, species life stages with different labels, appearances, and statistics, perhaps animal training, attack animals, and so on. Piotr is also working on some other juicy features: new varieties of one-use ancient artifacts for psychic attacks and control, a new room stats system so pawns get happier when they have impressive rooms and heal better in sterile hospitals, and passive ‘facility’ buildings that enhance the function of other nearby buildings.

So I think Alpha 12 will be an important update, but it will take some time. It might not be finished before the end of August, in which case it’ll have to wait until 2016 (since I’m taking a break starting in September). I considered just releasing what we have but I really don’t want to release animal husbandry in a half-done state. I want you to experience the glory of it all at once.

In general everything’s been going great, and work is progressing rapidly. Currently I, Piotr, Rhopunzel, and Al are all working on RimWorld, so great new stuff is getting slammed in every day. It’s fun!

And now, a picture of wargs and Yorkies next to a pile of corpses.



Alpha11b released

Posted July 4th, 2015 by Tynan Sylvester

I’ve just released RimWorld Alpha11b! This is a fix-and-adjust build without crazy new features. You can still load saves from Alpha 11 (though they will report some errors on loading and have a few minor issues around load time, they should play fine in the long term).

Mods might become incompatible. I’ve tried to keep the API the same as it was before, but a few places have necessarily changed. Also, since the DLL was recompiled, the ABI might not be identical. This means the functions and variable names are the same, but the compiler might have changed the way the bits and bytes are passed around, causing code compiled against the old DLL to not work properly when it tries to talk to the new DLL. This means:

  • Simple mods (especially those which are purely XML data, images, and sounds without any code) should still work without any changes.
  • Mods with code might work without changes, but there’s a good chance they’ll need to be recompiled against the new DLL.
  • A few mods will actually need to have code changed if they touch parts of the API that I changed.

If you own the game, you can get the new version by re-downloading from the link you used before (it is a permanent link and always has the newest version). Anyone still having trouble should start at the support page. A new email will not be sent for this update.

Full change list:

  • Colonists will now try to avoid pathing outside their allowed area.
  • Open doors equalize temperature faster.
  • Much, much smarter sapper escort AI.
  • Sapper now avoid mining high-health ore while finding tunnelling paths.
  • Reorganized and clean up options menu and graphics settings.
  • Mods config page shows load order of mods.
  • Toxic fallout kills plants much more slowly.
  • Enemies (especially wargs) now ignore unpowered unmanned turrets and mortars.
  • We no longer allow buying back prisoners you just sold as a way to insta-recruit anyone.
  • Can no longer sell rotten items.
  • Treatment result is now indicated with a text mote, not a global message.
  • Adjusted a bunch of sound volumes.
  • Fixed pirate merchants only bringing slaves when population is high. This should be reversed.
  • Reworked how slave prices are calculated so they take injuries, capacities, and skills into account better.
  • Colonists now harvest planted trees on their own.
  • Optimizations to grower work scan algorithms.
  • Cleanup on main menu background image.
  • Smelt slag recipe can use do until you have X.
  • Siegers can never use melee weapons (too exploitable).
  • New sound: warg voices.
  • New sound: treatment.
  • New sound: medicine used successfully.
  • Player-created backstories and translations have been updated.
  • About 150-200 bugfixes – some big, some small.

Steam release moved to 2016

Posted July 3rd, 2015 by Tynan Sylvester

So after some great conversations about the Steam release and some more thought, I’ve decided to hold off on the Steam release until next year.

Originally, I wanted to get the Steam release out so you would all have access to Steam features and automatic updates while I was on break. To alleviate concerns about me not being around for my break, I thought I’d write a blog post describing the exact state of the game and where development was heading. The idea was that anyone could read it and decide for themselves whether they wanted to buy the game or not.

However, on further discussion it seems like a risk. These days, people assume a lot about a developer and their process very quickly, and a lot of it can be negative. A lot of people have been burned. So no matter how much I communicate, a lot of those messages won’t be read, understood, or even believed. I hope I’ve built up some trust among RimWorld players by my actions in the past – but with a Steam release come a lot of new players who don’t know me from a hole in the wall. My fear is that misunderstandings and accusations around me taking a break soon after release would taint what I think will be an otherwise strong release on Steam.

The benefit of pushing to Steam now doesn’t seem worth it. Steam Workshop is nice, but a lot of people don’t use it even when they have the option. Automatic updates are cool, but there’s not much point when the game isn’t being updated because the developer is on break. We already have a well-working release system that’s served us all well for almost two years. So there’s just no great hurry there that outweighs the risks.

I’m sorry for the confusion on this and I hope this isn’t letting anyone down too much. Of course, the game itself will be the same either way (in fact, we might get more content out in the near term because of time saved from Steam release hassles). I also really appreciate everyone who took the time to write out a full set of thoughts on this topic. You’re not just giving me two-line low-effort responses; you’re giving me entire essays, and it’s really useful. I am listening and learning from you guys all the time.

In other news, Piotr Walczak, Polish coding prodigy has rejoined me after his school year. You may remember him as the guy who wrote the original code for the health system last summer. Having him around should help increase development speed.

Alpha11b is approaching final testing. It’s a massive bugfixing, tuning, and adjusting release, with hundreds of bugfixes and many balance changes and other small improvements. It’s also compatible with Alpha 11 saves! So look for that to come out soon.