RimWorld moves from Unity to Ludeon’s in-house Waylith Engine in update 1.7

Ludeon Studios is moving RimWorld off Unity and onto its own in-house Waylith Engine with the upcoming update 1.7. Rock Paper Shotgun reported that the studio announced the change in a Steam update and said performance should improve by roughly two to four times.

According to Rock Paper Shotgun, Ludeon says the sci-fi colony sim will “look and play exactly the same” on the new engine. The studio says the gains cover startup, load times with large mod lists, map and world generation, and ticks per second. In one example Ludeon gave, a modpack with 1,500 mods took six minutes to load instead of 14.

Ludeon also says community mods will keep working after the engine change. Because the version number is changing, some mods may be labeled as potentially unsupported, but the studio says they will still run as before. Players can also bring their 1.6 saves into 1.7, so updating won’t cost them any progress.

There is a hardware warning, though. Rock Paper Shotgun quotes the announcement as saying that “if your PC is more than 10 years old, 1.7 may not run on it.”

Update 1.7 is available now on a beta branch on Steam, so players and modders can test it before the full release. Ludeon has not given a date for that release in the material available. Rock Paper Shotgun noted that players commenting in a Reddit thread about the announcement mostly reported better performance and working mods. Some said the new version uses noticeably more RAM.

Rock Paper Shotgun compared the move to Mega Crit’s decision to switch Slay the Spire 2 from Unity to Godot. That switch came after Unity tried to bring in a per-installation fee for developers, a plan the company later dropped.