update · October 12, 2026
RimWorld Update 1.7 Moves the Game to the Waylith Engine
Ludeon Studios is shifting RimWorld from Unity to its new in-house Waylith Engine in update 1.7, delivering performance gains up to 4x. The update is currently available on the unstable Steam branch.
Ludeon Studios announced update 1.7 for RimWorld, transitioning the colony survival game from the Unity engine to Waylith, an in-house engine built by the developer. While the game looks and plays identically, internal testing shows performance improvements ranging from 2x to 4x. Update 1.7 is available now on the unstable Steam branch for testing.
Performance and Mod Loading
Compared to version 1.6, the Waylith engine delivers faster startup times, quicker game loads for large mod lists, faster world and map generation, and higher ticks-per-second. Stress tests on late-game colonies showed a 2.2x performance boost. A test modpack containing 1,500 mods saw its load time drop from 14 minutes down to 6 minutes.
Compatibility and Savegames
Version 1.6 savegames load correctly on version 1.7, and 1.7 saves work if reverted to 1.6. Most existing mods function without author changes, though some may display a yellow potentially unsupported warning due to the version number change. Players on PCs older than 10 years may encounter launch issues, which Ludeon is tracking on the official RimWorld development Discord.
Tools for Modders
Modders can utilize the latest C# language features and build complex mods without performance penalties. Visual changes and custom effects are also more accessible. Modders should publish a 1.7-compatible version once tested to remove the warning flag for players.
Why this patch matters
Update 1.7 focuses squarely on technical foundation, offering substantial load time and tick rate gains for heavy colonies and massive mod lists without breaking existing save files.