RimWorld 1.7 moves from Unity to Ludeon's in-house Waylith engine

Ludeon Studios has released RimWorld update 1.7 and moved the game off Unity onto its new in-house Waylith engine, claiming substantial performance gains. In testing Waylith boots, loads large mod lists, generates maps and worlds, and runs ticks much faster - Ludeon reports 2-4× improvements in many areas, a 2.2× speedup in a late-game stress test, and a 1500-mod pack loading drop from 14 to 6 minutes. Visually and gameplay-wise RimWorld remains the same, but players should notice smoother performance with big colonies, lots of animals, or heavy mod use. The update is available now on an unstable Steam beta branch for testing.

Savegames and most mods remain compatible: 1.6 saves load on 1.7 and 1.7 saves can be opened in 1.6, and the vast majority of mods work without changes (some will show a yellow “potentially unsupported” flag until authors publish a 1.7-compatible version). Very old PCs (over ~10 years) may fail to run 1.7; Ludeon asks affected users to report hardware on the development Discord. Modders gain access to newer C# features, easier performance-safe complexity, and better options for visuals and effects. Ludeon thanks modders who helped test and hints that Waylith will power another upcoming game.