Getting Started with Slime Rancher 2 Modding
What's different from Slime Rancher 1, and the IL2CPP MelonLoader install path
If you've modded Slime Rancher 1 and you're moving to Slime Rancher 2, throw out most of your muscle memory. The two games look identical but their modding stacks are entirely different — SR2 is IL2CPP-compiled, which means MelonLoader's IL2CPP branch instead of the Mono branch, no SRML, and a smaller catalogue of mods to draw from.
This guide walks the SR2-specific install path and the things that catch SR1 modders off guard.
What's different from Slime Rancher 1
| Slime Rancher 1 | Slime Rancher 2 | |
|---|---|---|
| Unity runtime | Mono | IL2CPP |
| Loader | MelonLoader (Mono) | MelonLoader (IL2CPP) |
| Helper framework | SRML | None comparable |
| Catalogue size | Mature, hundreds of mods | Smaller, mostly framework-tier |
| Save format | Stable | Still in flux (Early Access) |
Mods compiled for Slime Rancher 1 will not load in Slime Rancher 2. The binaries are incompatible.
Step 1 — Install MelonLoader (IL2CPP build)
Download the MelonLoader installer and run it. Point it at SlimeRancher2.exe. The installer detects IL2CPP automatically and installs the IL2CPP-capable hook (rather than the Mono one).
First launch takes longer than on Slime Rancher 1: MelonLoader needs to dump and generate the IL2CPP interop assemblies on first run. Expect a 30–60 second startup the first time, then back to normal launch speeds.
The MelonLoader console opens alongside the game. The Slime Rancher 2 main menu shows the MelonLoader tag when everything's hooked correctly.
Step 2 — Install your first mod
The Slime Rancher 2 mod community is small. Check Nexus Mods Slime Rancher 2 page and the SR2 modding Discord (linked from Nexus) for the current crop.
Mods are MelonLoader .dll files dropped into the Mods/ folder Slime Rancher 2 created on first launch. There's no SRML-equivalent meta-framework to install first; mods target MelonLoader directly.
Restart the game. The MelonLoader console logs each mod's load on startup; check for any red error lines before you start playing.
Step 3 — Save compatibility
Slime Rancher 2 saves are in %AppData%/../LocalLow/Monomi Park/Slime Rancher 2/. Back them up before installing your first mod.
Slime Rancher 2 is still in Early Access. Save schemas change between major patches; a mod that worked with version 1.0 may break on 1.1 even without being updated, because the underlying save format shifted. Pin your game's Steam beta branch if you're running a long playthrough with mods.
Step 4 — Co-op with mods
Slime Rancher 2 supports up to 4-player co-op. With mods, all participants need:
- The same MelonLoader version
- The same mod set
- Identical mod versions
The host's save is the authoritative state. Joiners with missing mods get warnings and often immediate disconnects.
There's no built-in mod sync. Coordinate manually in Discord or via a shared cloud folder.
Common gotchas
- You installed the Mono MelonLoader build. MelonLoader picks the right branch automatically when pointed at SlimeRancher2.exe, but if you manually overrode the version, you might have the SR1 branch on the SR2 install. Reinstall via the installer to recover.
- First-run IL2CPP generation seems hung. The first MelonLoader-enabled launch of Slime Rancher 2 takes a long time because it's generating the IL2CPP interop assemblies. It's not actually hung — wait it out. Subsequent launches are fast.
- Mod targeted an older Slime Rancher 2 version. Early Access version mismatches are the leading cause of "mod doesn't load" reports. Read the mod's README for its supported game version.
- No SRML for SR2. Searching for "SRML for Slime Rancher 2" produces dead ends. There isn't one. Mods target MelonLoader directly.
- Co-op disconnects on join. Almost always a mod-set mismatch between host and joiner. Compare mod lists.
The Slime Rancher 1 guide here covers the Mono-Unity equivalent of this setup if you're modding the original. The two paths are not interchangeable.