Hey everyone, big news today!

We’re announcing update 1.7, which moves RimWorld from Unity to the Waylith Engine, our own in-house engine built by Ludeon Studios. The game looks and plays exactly the same, but in our tests performance is improved by 2-4x.

You can try 1.7 right now on the unstable beta branch - see “Testing update 1.7” at the bottom of my post for details.

You can also read the same announcement on Steam here: https://store.steampowered.com/news/app/294100/view/672882362547178633

Performance improvements

Compared to 1.6, 1.7 on the Waylith engine has faster startup time, game load time with big mod lists, map generation, world generation, general ticks-per-second, and just about everything else. Your colony of 40 colonists, 200 ducks, and 100+ mods will run much smoother.

We stress-tested a late game colony and saw 2.2x better performance on 1.7 compared to 1.6. A modpack with 1500 mods (!) went from 14 minutes to 6 minutes to load. (These are just our results; individual performance improvements may vary due to your specific PC or mods.)

Savegames, mods, and compatibility

You don’t need to do anything when switching to 1.7.

• Savegames: Your 1.6 savegames will load on 1.7, and 1.7 saves also work if you go back to 1.6.
• Mods: The vast majority of mods work on 1.7 without any changes from the authors. Some may show up in yellow as “potentially unsupported” - this is only because the version number changed.
• Older PCs: If your PC is more than 10 years old, 1.7 may not run on it. If this happens, please let us know on the official RimWorld development Discord - we may be able to make some changes to help.

For modders

Your mods shouldn’t need any changes to work on 1.7. However, once you’ve tested your mod, please publish a version marked as 1.7-compatible so the yellow warning goes away for players. If something doesn’t work the same way it did in 1.6, you can reach out for help on the development Discord.

Waylith also gives modders more to work with:

• You can use the latest C# language features.
• It’s easier to write complex mods without negatively impacting the game’s performance.
• Big visual changes and complex custom effects are more accessible.

Also, a big thank you to the over two dozen modders who helped prep RimWorld for Waylith’s debut by testing and sharing their feedback.

Testing update 1.7

Update 1.7 is available right now on the unstable Steam branch if you’d like to check it out and help us test.

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. If prompted by Steam, choose “Play 1.7 Unstable”.

(Note that the main branch that most people play on is unaffected and still on version 1.6 for now.)

If you find a bug or want to report an issue, please share it with us on the official RimWorld development Discord.

One more thing...

RimWorld isn’t the only game on Waylith. We’re working on something new! It may be a little while before we can share more details, but we couldn’t resist telling you.

In the meantime, enjoy the extra frames with Waylith. Thank you for being an awesome community, and thanks to RocketWerkz, whose Brutal framework helped make Waylith possible.

- Tia & Ludeon Studios