Rimworld: Update 1.7 Moves the Game to the Waylith Engine

Ludeon Studios has announced Rimworld update 1.7, which moves the game from Unity to the Waylith Engine, the studio's own in-house engine. The announcement went up on October 12, 2026, and the developers say the game looks and plays exactly the same.

What does change is speed. If you run a big colony or a long mod list, this is the update you've been waiting for. Below, we cover the performance numbers, what happens to your saves and mods, and how to try 1.7 right now.

What the Waylith Engine Changes

According to Ludeon's tests, performance is improved by 2-4x. Compared to 1.6, the studio lists faster startup time, faster game load time with big mod lists, and faster map generation and world generation. General ticks-per-second are better too, along with "just about everything else."

Ludeon shared two stress tests in the official announcement:

• Late game colony: 2.2x better performance on 1.7 than on 1.6.
• 1,500-mod modpack: load time dropped from 14 minutes to 6 minutes.

These are the developer's own results, so your numbers may vary with your PC and your mods. Ludeon also warns that a PC more than 10 years old may not be able to run 1.7. If that happens, the studio asks you to report it on the official RimWorld development Discord, since it may be able to make changes to help.

Saves, Mods and Modders

You don't need to do anything when you switch to 1.7. Your 1.6 savegames will load on 1.7, and 1.7 saves also work if you go back to 1.6.

The vast majority of mods work on 1.7 without any changes from their authors. Some may show up in yellow as "potentially unsupported," but Ludeon says that's only because the version number changed. Modders should publish a version marked as 1.7-compatible once they've tested it, so the warning goes away for players. If a mod behaves differently than it did in 1.6, modders can ask for help on the development Discord.

Waylith also gives modders more to work with. You can use the latest C# language features, complex mods are easier to write without hurting the game's performance, and big visual changes and custom effects are more accessible. Ludeon thanked the over two dozen modders who tested the engine before its debut.

How to Try Update 1.7

Update 1.7 is available now on the unstable Steam branch. Right-click RimWorld in your Steam library, select Properties, open the Betas tab and choose the branch "unstable." Restart Steam if the game doesn't update on its own, and pick "Play 1.7 Unstable" if Steam prompts you. The main branch most people play is unaffected and still on 1.6 for now.

Ludeon also teased that RimWorld isn't the only game on Waylith, saying it's working on something new with no details yet. While you wait, our guides to the best Rimworld traits and every room type will help your colony hold up once 1.7 lands.