A wrong load order causes half of all the red errors in the log. Mods apply from top to bottom: if two mods change the same thing, the one lower in the list wins. That is why libraries and frameworks must load before content, and patches — after everything else.
The basic mod order template
- 1Core (the game itself) — always first, never move it.
- 2DLC: Royalty → Ideology → Biotech → Anomaly — in release order.
- 3Harmony — the shared patcher, right after Core and DLC.
- 4HugsLib — the utility library, right after Harmony.
- 5Frameworks: Vanilla Expanded Framework, Humanoid Alien Races and other series "core" mods.
- 6Large content mods and gameplay overhauls (Combat Extended, Hospitality and the like).
- 7Small mods: weapons, furniture, apparel, QoL utilities.
- 8Compatibility patches — at the very bottom.
The built-in mod list highlights dependencies and offers a sort button, but do not trust it blindly: mod authors set their requirements by hand, and not always accurately.
Why Harmony has to be first
Harmony does not change your saves — it gives the mods below it in the list a safe patching mechanism. If Harmony ends up below a mod that requires it, you will see a "requires Harmony" error on load and the mod will not work. The same goes for HugsLib: it must sit right after Core, which its description states outright.
Automatic mod sorting
Utilities like RimSort analyse mod dependencies and sort them automatically using a community rule database. It is a good starting point for a 50+ mod list, but always check the final order with your own eyes: auto-sorters cannot know every unconventional dependency out of the box. For step-by-step installation instructions, see our guide on how to install RimSort.
Typical symptoms of a wrong order
- Red errors on startup mentioning XML, def or duplicate — almost always the order or a conflict.
- A mod claims a feature but it is missing in-game — another mod lower in the list overrode it.
- "Requires Harmony/HugsLib" in the error — the library sits below the dependent mod.
- Items vanished after updating the list — a content mod loaded before its framework.
Change the order one step at a time and restart the game: that way you immediately see which move fixed (or broke) the list.
For finding the culprit among a hundred mods, see the guide on RimWorld mod errors and conflicts. And if the game simply runs slow, start with Performance Fish and RocketMan — they speed RimWorld up regardless of load order.
Harmony
by Brrainz
Harmony is the shared patch library used by many RimWorld mods. This mod provides Harmony to the game so other mods can depend on one common version instead of each shipping their own copy. For play
HugsLib
by Symbolic
Shared-functionality library for many RimWorld mods, with the Ctrl+F12 log publisher for easy bug reports. Place right after Core.
Performance Fish
by Michael
Performance Fish patches RimWorld's core methods for better framerates and tick times with identical behaviour - big lategame gains, made by Bradson, safe alongside RocketMan.
RocketMan - Performance Mod
by SubmarineMan
RocketMan is a RimWorld performance mod built to claw back FPS and cut loading times in heavily modded games - its author credits nine months of development and over 1,200 hours of testing, with gains of up to 500 TPS reported.
Load order FAQ
Where do RimWorld translations go in load order?
Localizations belong at the very bottom of the list, after every mod and patch. Translation files must override original strings, so the lower an entry sits, the more likely its text wins. The only exception is translations whose author explicitly recommends another spot.
Do I need Harmony if no mod requires it?
Yes. Harmony is the baseline patching library — almost every content mod depends on it directly or through compatible frameworks. Keep it right after Core and DLC; that is the convention understood by sorting utilities and mod authors alike.
In what order should RimWorld DLC be installed?
Release order works best: Royalty → Ideology → Biotech → Anomaly → Odyssey. The expansions are independent, so the exact sequence barely matters — just keep all of them after Core and before libraries and content mods.
Is it safe to reorder mods mid-playthrough?
Content mods are usually safe to move: they add items and events rather than rewrite core systems. Moving libraries (Harmony, HugsLib), frameworks and hard-patching mods is riskier — test the new order on a throwaway colony and read the log before returning to your main save.
Where do Performance Fish and RocketMan go?
Performance mods belong near the bottom: after content mods but before patches and localizations. Performance Fish requires Harmony above it. Always check the mod description — authors normally specify the allowed range of the load order.