Ludeon Studios posted an announcement on October 12, 2026, detailing update 1.7 for RimWorld. The update moves the game from Unity to the Waylith Engine, the studio’s own in-house engine. The announcement is available on the RimWorld Steam news page.
What Changed
The update 1.7 brings the Waylith Engine to RimWorld. The game looks and plays the same, according to Ludeon, but performance is improved by 2-4x in their tests. Players can try 1.7 on the unstable beta branch right now.
Performance improvements are broad. Compared to 1.6, 1.7 on Waylith has faster startup time, game load time with big mod lists, map generation, world generation, and general ticks-per-second. A colony with 40 colonists, 200 ducks, and 100+ mods will run much smoother, the announcement says.
Ludeon 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. The studio notes these are just their results and individual performance may vary due to specific PCs or mods.
Savegames are compatible in both directions. 1.6 savegames will load on 1.7, and 1.7 saves also work if a player goes back to 1.6. No action is needed when switching.
The vast majority of mods work on 1.7 without any changes from authors. Some may show up in yellow as “potentially unsupported” only because the version number changed. Modders should publish a version marked as 1.7-compatible after testing so the yellow warning goes away for players.
Older PCs may have trouble. If a PC is more than 10 years old, 1.7 may not run on it. Ludeon asks players to report this on the official RimWorld development Discord, as they may be able to make changes to help.
Waylith gives modders more to work with. They can use the latest C# language features, write complex mods without negatively impacting game performance, and access big visual changes and complex custom effects more easily. Over two dozen modders helped prep RimWorld for Waylith’s debut by testing and sharing feedback.
Update 1.7 is available on the unstable Steam branch. Players can access it by right-clicking RimWorld in their Steam library, selecting Properties, then the Betas tab, and choosing branch “unstable”. Restart Steam if the game does not automatically update, and choose “Play 1.7 Unstable” if prompted. The main branch most people play on is unaffected and still on version 1.6 for now.
RimWorld isn’t the only game on Waylith. Ludeon is working on something new, but it may be a little while before more details are shared.
Who It Affects
All RimWorld players will eventually see the engine change, but the immediate beta is for those who opt into the unstable branch. Modders are asked to test and mark compatibility. Players with PCs over 10 years old may not be able to run 1.7 and should report issues on the development Discord.
Your colony of 40 colonists, 200 ducks, and 100+ mods will run much smoother.
For all RimWorld announcements, check the RimWorld update tracker.
