On the upcoming Steam release

Posted July 1st, 2015 by Tynan Sylvester

The news that people have been asking me about for years is finally here! I’m planning on releasing RimWorld on Steam Early Access around the end of July or early August.

At that time, the key distributor will be set up to give out Steam keys to existing buyers (currently it only gives your non-Steam download links). I’ll try to get the keys up at the same time as the Steam release, but be warned that there might be a day or so of delay. In either case, the content will be the same on and off Steam.

Steam Workshop will be supported from day one of the Steam release, so it’ll be extremely easy to subscribe to mods. In fact I’m a little worried that people won’t come to our thriving mods forum any more! But I think it’ll be okay. A community this awesome is about more than just getting the mods.

In the run-up to the Steam release, I’ve been focusing my efforts on perfecting what there is of RimWorld rather than biting off chunks of new content. If you read my changelog you already know that I’ve been obsessively bugfixing for a month now. As I mentioned in the Alpha 11 release video, I’m pretty satisfied with the shape of the game. Up until Alpha 11, there were always big holes in the design. Back in the days of yore it was the lack of real hauling and stockpiling (resources were stored in hammerspace, like StarCraft II). Then it was the monotony of a single enemy type with a single strategy. Then the monotony of a single biome. As each piece was added, it filled in a missing piece in the design. The last hole was the one represented by the all-powerful killbox strategy which funneled dumb enemies into a single turret-lined room. Alpha 11’s new sapper strategy solved that.

Now, for the first time, I look at the design and I don’t see gaping holes that need to be filled. Of course, there are still countless things that could be added to the game. I have a document listing hundreds of them. But they all feel optional to me. What’s there is a rounded, integrated design. In my mind the design always used to look like an irregular lump of Swiss cheese; now it’s more-or-less rounded and more-or-less smooth.

So is it done? I’ve thought a lot about what it means to call a game “done”. Ten years ago, a game was done when it was printed to disc. But with digital distribution, we never lose the ability to keep changing a game. So when is a game done? Is it just when you stop adding things? No, because a game can be abandoned without being finished. Is it when there’s nothing else that could be added? That’s not reasonable; I could work on RimWorld for 50 years and never satisfy that. In the end, I think that a game is done when promises have been fulfilled, and there aren’t holes in the design. And we’re reached that point, so RimWorld is done.

That said, just because RimWorld is done doesn’t necessarily mean I’m done with it.

I like working on the game, you all like playing it, and it’s profitable. So I probably will add more content to the game. In the meantime, though, I think it’s time for a bit of a break. I’ve been working on RimWorld and its prototypes for going on three years straight now, and my hours are usually pretty long. I’m starting to feel a bit of burnout. I often seem to develop this dull ache behind the eyes after a couple hours of work. I have trouble concentrating for the lengths of time that used to be normal for me. For that reason – and just because I believe in having a life that isn’t all work – I’m taking some time off from full-time RimWorld development starting in September. Currently it’s looking like it’ll be about six months. I’ll still be around to interact, but I won’t be developing constantly like I have been.

I can’t say exactly what will happen when I return. I might just take the feedback from the Early Access release, integrate it and release RimWorld 1.0 without major new features. Or, I might continue developing the game for years. As I said, I like working on RimWorld, but I’ve also learned that the future is very uncertain and it’s a bad idea to make promises you’re not sure you can keep. That’s part of why I’m telling you about my break now, before the big Steam release. In any case, as always, I encourage people to only make buying decisions about the game based on what it is today. Please don’t ever buy any game – including mine – based on a guess at what it might some day become. Hype trains crash a lot.

So – that’s all the news! I also want to say thank you. There are a lot of scary stories about indie development, and back when I quit Irrational I wasn’t looking forward to facing the poverty and vicious online hatred I kept hearing about. Thankfully, this whole process has actually turned out to be great all around. You’re make this community fun and interesting to interact with. This is an awesome job and I very much appreciate you in giving it to me.

New trailer released

Posted June 13th, 2015 by Tynan Sylvester

I’ve just released a new RimWorld trailer! The format is the same as the old one, but all the content has been updated to the new hotness. Enjoy.

RimWorld Alpha 11 – Sappers and Traps released

Posted June 10th, 2015 by Tynan Sylvester

It’s here! This update includes clever new AI strategies including sappers who blast and dig around your defences and raiders who burn crops. I’ve also added a number of incidents, including several long-term atmospheric conditions like volcanic winter and toxic fallout. There is also an array of new traps for players to use, dozens of other new features and hundreds of fixes and small improvements. A full change list is at the end of this post. If you wish, you can also read my day-to-day work log here.

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 this thread. 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:


  • Added new raid type: sappers.
  • Sappers attempt to dig or blast their way around your hardest defensive point. The circumvent ‘killbox’-like strategies.
  • Enemies now flee things that are about to explode
  • Enemies remember trap positions that their faction has encountered before, and avoid them.
  • Raiders opportunistically ignite crops on fire.
  • Pawns can now do ‘job override’ checks to see if a new job should start before ending their current job. These are now used liberally to have pawns respond faster and more intelligently to changing conditions (especially in combat).
  • Pawns check for job override when taking damage. It will no longer be possible to bug out the centipede enemy and kill him at close range while he tries to take a firing position.
  • Enemies no longer take unpowered player turrets as primary targets.
  • Pawns choose sky-gaze, wander, eating and other positions by traversing the region graphic instead of by random coordinate scattering, which solves problems with them taking long paths around long walls.


  • Added deadfall trap: A simple rearmable trap that falls on enemies and damages them.
  • Added IED trap: An artillery shell connected to a trigger that detonates after a short delay.
  • Added incendiary IED trap: Like IED, but sets fires.

New incidents

  • New incident: Toxic fallout. A toxic cloud that lasts for days or weeks. It kills plants, rots food, and slowly poisons people outside. Toxic buildup in characters leads to vomiting, dementia, and eventually death.
  • New incident: Volcanic winter. Lasts weeks or months and significantly reduces temperatures and light levels, leading to poorer harvests.
  • New incident: Manhunter pack. A pack of deadly wargs arrives and stalks the local area for a while before moving on. Fight them or hide inside from them.
  • New incident: Chased refugee. A refugee radios and offers to join the colony if you’ll fight the raiders on his tail.
  • New incident: Psychic soothe. The opposite of a psychic drone.

Allowed areas

  • Assign colonists to allowed areas.
  • Every item and location outside the allowed area is considered forbidden.

Storyteller changes

  • Storytellers will never entirely disallow events because of population.
  • Randy’s event chances are affected by population (somewhat).
  • Re-tuned storyteller population intent based on new output tables for smoother population gain with higher maximum and better recovery at small populations

Ice sheet

  • Ice sheet biome is now playable (though perhaps not survivable).


  • Added strip designator to reduce stripping micromanagement.
  • You can toggle allowing sowing in a growing zone.
  • Doors can be held open.
  • Door locking is now door forbidding (it’s clearer).
  • Added copy/paste functionality for storage zone/building settings.
  • World data now saves into map file to prevent game state confusion with multiple saves on one world.
  • Added new joy activity: build snowman.
  • You can now remove floors to reveal the terrain underneath.
  • You can now perform surgery on guests. Violating surgery will anger their faction.
  • Guests are smarter and no longer walk out of the colony bleeding.
  • Added new hairs donated by Shinzy.
  • Slave trader changed to pirate merchant, can still show up to buy slaves even when your population is high (though they may not carry any).
  • Hundreds more bugfixes, tuning changes, optimizations, and other small improvements.

Bug warning: Don’t change storytellers

Posted May 1st, 2015 by Tynan Sylvester

A bug has been discovered that will break storytellers if you change between Randy and Cassandra/Phoebe.

If you do this, the game will simply cease sending events. No traders, no raids, nothing.

You can still change difficulties. You can also still change between Cassandra and Phoebe. Just don’t change to or from Randy.

Sorry about that. Will be fixed in next build.

Hotfixed to Alpha10e (updated to Alpha10f)

Posted April 22nd, 2015 by Tynan Sylvester

This hotfix was broke for the first few hours of its release, when it was called Alpha10e. If you got it during that time, please re-download the fixed Alpha10f. The fix solves an issue in Alpha10e where rain would never put out fires, leading to the whole map burning down.

This small hotfix cleans up some minor issues that remained in Alpha10d.

To update, just use your existing download link from your last update email – it always gives the latest version. Save games from Alpha 10 will still work. To install, delete your old install directory and unzip the new Alpha 10f files to a clean empty folder (your save data is not stored in the install directory).


  • Reworked apparel optimization AI. Now they very much prefer wearing anything over wearing nothing (so they don’t walk around naked with clothes on the floor), and have a lower threshold of quality difference to replace apparel.
  • Optimized fire significantly so large fires won’t slow down your computer as much.
  • Some very minor fixes.

Hotfixed to Alpha10d

Posted April 20th, 2015 by Tynan Sylvester

So I got to have that special moment where you’re looking at some game code and you realize that the game you shipped last week to 75,000 people is totally horribly broken in subtle but game-destroying ways. This is the hotfix to the problem I found and others. Up to now, Alpha 10 has been basically broken.

There were a number of issues but the biggest one was probably the broken enemy fleeing and recruitment code that made it way too hard to get new people.

Sorry about releasing a kind-of broken version. I’m thinking that for Alpha 11 I’ll start doing public unstable builds a week before the stable release. It’s getting really hard to catch all the bugs in the game as it becomes more complex and it takes longer to play.

To update, just use your existing download link; it always gives the latest version. Save games from Alpha 10 will still work. To install, delete your old install directory and unzip the new Alpha 10d files to a clean empty folder (your save data is not stored in the install directory).


  • Fixed and rebalanced prisoner recruiting: Prisoners no longer get cabin fever and no longer have a joy need (until we get support for proper prison complexes). They can be recruited at any mood over 35% (though the chance may be very low).
  • Fixed a units change bug that caused 40% of enemies to flee after taking one hit, and other enemies to never flee. Now the flee properly with individual health thresholds again.
  • Fixed PawnName parsing so pawns with apostrophes in their names will work.
  • Cleaned up and robustified the AI with regards to finding a space to stand next to medical beds. Abolished the “medical bed needs headspace” alert as it’s no longer needed.
  • Fixed a bug that caused colonists to get stuck switching apparel over and over given certain weather conditions and combinations of apparel (they were considering the needed warmth in relation to their own current apparel instead of in relation to their absolute naked needs).
  • Fixed a bug that would crash the UI if colonists hauled a sculpture or TV while the player was selecting an install location.
  • Fixed bug that caused pawns to sometimes teleport to the bottom left corner of the map.
  • Fixed the needs tab not displaying on animals if a human was never previously selected with the needs tab.
  • Fixed a bug that caused colonists to spaz out around the billiards table when they reached full joy instead of just ending the job.
  • Some minor storyteller tuning.
  • Some minor typo fixes in game text.

Hotfixed to Alpha10c

Posted April 17th, 2015 by Tynan Sylvester

I’ve released another hotfix addressing some bugs and balance issues. Thank you for being patient with these!

This is a silent hotfix; there will be no update email. Just re-download from your existing link.

Save games from Alpha 10 will still work. To install, delete your old install directory and unzip the new Alpha 10c files to a clean empty folder (your save data is not stored in the install directory).

  • Changes to speed up pacing: reduced building costs, start with more steel, a colonist will join reasonably early (on Cassandra or Phoebe). Recruiting is slightly easier. Joy tolerance is gained slower.
  • You’ll get a letter when an animal goes insane due to taking damage. Also, the chance of this happening is reduced.
  • Colonists will stand away from boomrats while executing them.
  • Joy-related thoughts are broken up more finely and balanced.
  • Planning designation has dark outline for easy visibility.
  • Trees are still sowable, but it takes a lot of time to sow them.
  • Bugfix: Colonists will no longer get stuck if you put a blueprint under a hopper and they try to fill it.
  • Bugfix: Colonists no longer relax socially in prisons.
  • Bugfix: Cooks will no longer make more meals than requested in the “do until you have X” bill repeat mode.
  • Bugfix: Unpowered lamps will no longer start glowing after being destroyed.

Hotfixed to Alpha10b

Posted April 16th, 2015 by Tynan Sylvester

I’ve released a quick hotfix for Alpha 10 that should address some bugs, design mistakes and imbalances in the first released version.

You should get an update email some time today. Or, you can just download from your existing link (as it always gives the latest version).

Save games from Alpha 10 will still work. To install, delete your Alpha 10 install directory and unzip the Alpha 10b files to a clean empty folder (your save data is not stored in the install directory).

Change list:

  • Substantially increased the speed of joy gain.
  • Door locking is really door forbidding, so it happens instantly again and does not require colonist interaction.
  • Trees are sowable again.
  • The first enemy raider will never flee (makes him easier to capture).
  • Colonist names can now include numerals.
  • Fixed colonist outfit apparel search so colonists with guns will not take personal shields.
  • Improved colonist outfit apparel selection in general.
  • Some other smaller fixes.

Edit: Just realized comments were closed. Opening them…

RimWorld Alpha 10 – Joy System released

Posted April 15th, 2015 by Tynan Sylvester

Alpha 10 has arrived! This time we’ve added a new “joy” need with a bunch of ways to fulfil it, new timetable, outfits, and thing filter management tools, and dozens of smaller improvements. A full change list is at the end of this post.

If you own the game, you can get Alpha 10 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 this thread. 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:


  • New joy need added. Colonists want to have “joy”, which means anything that lets the stop working and enjoy themselves for a while.
  • Added joy sources
    • Skygazing
    • Meditating/praying
    • Social relaxation around campfire or table, with or without beer
    • Horseshoes game
    • Chess
    • Billiards
    • Television (purchasable)
    • Telescope for astronomy (purchasable)
  • Added armchair and dining chair
  • There are various kinds of joy. Repeated use of the same kind of joy builds up a tolerance, reducing its impact. Colonists will prefer joy sources they are not already tolerant to. Result: it’s beneficial to provide a variety of joy sources.

Outfits system

  • New outfits manager system added. You can design ‘outfits’ (restrictions on what a colonist is allowed to a wear) and assign them to colonists in a central interface. Colonists will then independently work to find the best apparel possible given their outfit and the current season. They will automatically switch out damaged apparel for better apparel, or poor-quality apparel for high-quality apparel.
  • If the player manually assigns apparel, the colonist will never remove it until the manual assignment is cleared.

Timetable system

  • New timetable system added. You can assign each colonist a daily timetable which describes when they should sleep, work, have joy, or decide on their own.


  • Colonists can fall unconscious on their own if over-exhausted.
  • Reworked how melee verbs are selected so they’ll be selected with a bit more randomness. e.g. Someone with one scyther blade hand won’t use it exclusively; you’ll need to get them two if you want a true killing machine.
  • Beer can now be wielded as a weapon (like wood).
  • Passion flames are now displayed subtly on the work overview screen.
  • New end credits song from Al!
  • Reduced skill degradation rate.
  • Day length extended from 24,000 to 30,000 ticks. Days per month reduced from 12 to 10.
  • Hunters will now approach and execute downed animals at close range.
  • Reworked food search so it smoothly integrates information about food distance, taste, and psychological preference to get the most optimal food source.
  • Health tab now displays overall bleeding rate.
  • Starvation and blood loss are now staged and affect consciousness as they worsen.
  • Reworked how skills generate so there will be more initial skill variation and age affect starting skills more.
  • Rebalanced and reformatted plant ecology tunings to lengthen crop cycles and slow wild plant spread. Reworked plant growth in relation to light levels so plants can still grow slowly in dim light (e.g. tundra summers).
  • Pain now creates unhappiness.
  • String lists are now part of language data and can be translated.
  • Butcher table, sculptor’s table, and stonecutter’s table can now be made of various stuffs.
  • Trees are no longer sowable. Traders carry wood.
  • Characters will now sometimes resist arrest.
  • You can now set a minimum skill level on bills.
  • Visitors will now carry away wounded guests from their faction.
  • Hunted animals will occasionally fight back. Some animals always fight back.
  • Doctors now automatically rescue downed colonists.
  • Generalized toggle power interaction to ‘switch flicking’ and applied it to power switch toggling and door locking as well as building power on/off.
  • Many many other fixes, adjustments, and optimizations.

Edit: Just realized comments were closed. Opening them…

Hotfixed to Alpha9e

Posted February 23rd, 2015 by Tynan Sylvester

I’ve released a hotfix to Alpha 9, Alpha9e, that rebalances a few things and fixes a few issues. This is build 0.9.727.

You won’t receive an email for this hotfix as we don’t want to spam people. The download link is the same one you got all other versions of the game from. Your personal download link never changes and always gives the latest version.

You can update by deleting your old installed game, downloading the new build from your existing download link, and installing it to a clean empty folder.

If you need help with your download please email ludeonhelp@gmail.com.

All save games from Alpha 9 will still be playable and mod compatibility shouldn’t be affected.

Changes include:

  • Reduced room temperature equalization rates.
  • Room walls that are two or more cells thick now equalize temperature slower.
  • Balanced sieges to be slightly weaker.
  • Various tuning adjustments to several thought mood effects.
  • Removed “buildings need power” alert as it is annoying to see it when a power switch is off.
  • Fixed a bug that corrupts savegames if you sell a statue that is marked to be installed.
  • While firefighting, colonists will now fight any fire they walk into.
  • Fixed a bug that caused non-prisoner beds to be set as prisoner beds on load.
  • Fixed a bug that froze wounded colonist prisoners if they were marked to get doctor care.
  • Fixed a bug that prevented prisoners from using nutrient paste dispensers in their cells.
  • Fixed a bug that caused temperatures indoors to sometimes become NaN (not a number).
  • Fixed a rare bug that prevented running a game that saved with some corrupted work priorities data.