RimWorld players can now test a version that replaces Unity with Ludeon Studios’ own Waylith engine, with the developer reporting performance improvements of two to four times in its tests. Update 1.7 is available through Steam’s unstable beta branch, not the standard release, which remains on version 1.6.
In its update announcement on Steam, Ludeon says the engine switch preserves how RimWorld looks and plays. Existing colonies can make the move too: 1.6 saves load in 1.7, and saves made in 1.7 will still work if players return to 1.6.
There is a hardware warning worth checking before switching. Ludeon says PCs more than ten years old may be unable to run 1.7, and asks affected players to report problems through its development Discord so it can investigate possible changes.
Faster colonies and mod compatibility
The improvements cover simulation speed as well as waiting for the game to load. Ludeon reports faster startup, map and world generation, loading with large mod lists and general ticks per second. Its late-game colony stress test ran 2.2 times faster on 1.7, while a separate modpack containing 1,500 mods loaded in six minutes instead of fourteen. Those are the studio’s results, not a guaranteed gain on every PC or mod setup.
RimWorld’s colony simulation tracks individual colonists’ needs, relationships and injuries alongside animals, weather and emergencies. Faster simulation can therefore help with the busy settlements described in Ludeon’s announcement, not just shorten the initial loading screen.
Ludeon says the vast majority of mods should work without changes. A yellow compatibility warning can simply mean that a mod has not been marked for version 1.7; authors are asked to test their mods and publish a version flagged as compatible. Waylith also supports newer C# language features and, according to the studio, makes complex mods and custom visual effects easier to develop.
To try the beta, right-click RimWorld in the Steam library, open Properties, select Betas and choose the unstable branch. Restart Steam if the update does not start automatically, and select Play 1.7 Unstable if prompted. Ludeon has not given a date in the announcement for moving 1.7 onto the main branch.